[0001] The present invention relates to a method for casting a component for application
in a high wear industrial environment with a composite zone containing titanium carbides
in a matrix material. The composite zone is formed in-situ during casting of molten
bulk material and obtained by using a powder composition comprising reactant powder,
which forms the titanium carbides within the composite zone and comprises titanium
and carbon, and moderator powder, which forms the matrix surrounding the titanium
carbides within the composite zone and comprises metal powders.
[0002] In high wear industrial environments, such as those associated with the metallurgical,
mining, cement, recycling, energy, agriculture and offshore sectors, for example,
the surfaces of the implemented components undergo complex wear processes, due to
the physical phenomena occurring during service. Such phenomena include but are not
limited to crushing, fragmenting, milling, drilling, boring, loading, and locomotion
of solids, liquids and/or mixtures thereof. These wear processes, which include abrasion,
erosion, adhesion, surface fatigue and/or tribo-corrosion, result in the reduction
of component dimensions, ultimately causing loss of functionality and deterioration
of the given structural component. This necessitates the frequent replacement of these
components, increasing costs and reducing profitability of the utilized machines and
processing routes.
[0003] It is well known within the field, that in order to increase the life expectancy
of a component implemented in a high wear application field, the periphery of the
component, which is exposed to the wear conditions, and the inner bulk material, which
forms the main dimensions of the component, must exhibit high hardness and plastic
properties, respectively. This ensures a certain level of wear resistance, while simultaneously
averting complete brittle and/or sudden failure of the component.
[0004] Accordingly, it is common for finished components, i.e. those that have been formed
and are in or near their end-product dimensions, to be coated with hard surface layers
via such techniques as spraying, cladding, welding, plating etc. prior to fielding
said component. These layers usually contain a high content of ceramic phases, such
as carbides, borides and/or nitrides, arranged in a matrix material, generally composed
of a metallic material. Due to the application of the wear resistant coating subsequent
to component forming, complications due to bonding with the underlying bulk material
and complete covering, due to undercuts and other form specifications, arise. Furthermore,
the fabrication of such a component requires a multi-step manufacturing process, which
increases production time and therewith-associated costs.
[0005] As an alternative to the post-forming application of a hard coating, a harder periphery
zone of a component can be produced in-situ during the initial casting of molten bulk
material, thereby reducing the required manufacturing steps for a component.
[0006] The
WO 2017/081665 A1 discloses a casted component with a composite zone containing titanium carbides.
A mix of powders containing 100 wt.%, 90 wt.%, 70 wt.% 50, wt.%, 30 wt.% and 10 wt.%
reactant powder and 0, 10 wt.%, 30 wt.%, 50 wt.%, 70 wt.% and 90 wt.% moderator powder,
respectively, is utilized to form casting inserts. The reactant powders are composed
of 50 at.% Ti and 50 at.% C, while the moderator powder is a high-manganese steel.
The inserts are subsequently placed and fixed to walls of a cavity of a casting mold.
Six kilograms of a molten cast steel are poured into the mold, initiating a reaction
between titanium and carbon, by supplying thermal energy via the molten casting steel.
Due to a self-propagating high temperature synthesis (SHS) reaction, a composite zone
containing titanium carbides within a matrix composed of a high-manganese steel is
fabricated, thereby producing a harder zone of the component where the powder composition,
in the form of the casting inserts, was originally placed. The main dimensions of
the casted component is composed of the cast steel.
[0007] However,
WO 2017/081665 A1 further discloses that for the casted components manufactured implementing minimal
amounts of moderator powder (i.e. 0 wt.%, 10 wt.% and 30 wt.%), no stable composite
zones are obtained. Rather, fragments of titanium carbides within a high-manganese
steel matrix are randomly distributed throughout the main dimensions of the casted
component and do not remain at their intended location. This prevents the local reinforcement
of hardness values within the regions of the casted component that are exposed to
harsh wear conditions. Furthermore, due to their random distribution, the titanium
carbide phases do not establish an interconnected network, thereby reducing the component's
resistance to crack propagation and promoting local chipping. Consequently, an increase
in moderator powder to a minimum of 50 wt.% is required to establish a somewhat stable
composite zone. This, however, consequently reduces the amount of reactant powder
that can be implemented and the therewith-associated amount of formed titanium carbide
phases. As the titanium carbides are primarily responsible for the hardness of the
composite zone, reducing their quantity in order to ensure stabilization of the composite
zone results in a maximum hardness that can be achieved in the casted component.
[0008] Consequently, the present invention seeks to present a method for casting a component
with improved hardness properties in the composite zone of such a casted component.
[0009] The present invention proposes a method for casting a component for application in
a high wear industrial environment with a composite zone containing titanium carbides
in a matrix material, the composite zone formed in-situ during casting of molten bulk
material and obtained by using a powder composition comprising reactant powder, which
forms the titanium carbides within the composite zone and comprises titanium and carbon,
and moderator powder, which forms the matrix surrounding the titanium carbides within
the composite zone and comprises metal powders, characterized in that a powder composition
consisting of 55-80 wt.% reactant powder and 20-45 wt.% moderator powder is inserted
into a mold cavity with a wall thickness of at least 40 mm and at least 30 kg, preferably
at least 100 kg of molten bulk material is poured into the mold cavity.
[0010] The composite zone of the casted component is formed in-situ during casting of molten
bulk material. This occurs due to a known self-propagating high temperature synthesis
(SHS) reaction, which is initiated when molten bulk material reaches a powder composition
contained within a mold cavity. The powder composition encompasses elements and/or
compounds that form phases of the resulting composite zone. Furthermore, the powder
composition comprises reactant powder and moderator powder, which form the strengthening
phases and the surrounding matrix, respectively. The powder composition consists of
55-80 wt.% reactant powder and 20-45 wt.% moderator powder. The reactant powder consists
of 45 at.% Ti to 55 at.% C or 55 at.% Ti to 45 at.% powder, with a certainty of 2
%. Preferably, the titanium powder stems from a pure metal and merely contains impurities
associated with the manufacturing and/or pulverizing process. Most preferably the
titanium powder contains at least 95.5 at.% Ti, a maximum of 0.03 at.% H and a maximum
of 0.4 at.% O. The titanium powder has a particle size up to 70 µm, but preferably
no larger than 50 µm, more preferably no larger than 40 µm and are most preferably
35 µm. The titanium powder is preferably irregular sponge powder, usually manufactured
by hydrogenation-dehydrogenation. The carbon powder is preferably in the form of graphite,
flake graphite, amorphous graphite, black carbon, a carbonaceous material or a mixture
thereof. Preferably, the carbon powder contains at least 96.1 at.% C and a maximum
of 0.05 at.% S. The carbon powders have a particle size up to 20 µm, but preferably
no larger than 10 µm, more preferably no larger than 5 µm and most preferably between
5-10 µm.
[0011] The moderator powder can comprise at least one pulverized metal from the group of
Fe, Co, Ni, Mo, Cr, W, Al, Mn, Cu, Si, Ti, V, B, Li or Mg, preferably comprising at
least two of these metals. Preferably, the moderator powder comprises a mixture containing
Fe, Mn, Si and C powders, most preferably also containing Cr powder. The maximum amount
of H in the moderator powder is preferably 0.03 at.%. Preferably, the moderator powder
has a chemical composition associated with a grey cast iron, white cast iron, chromium
cast iron, chromium cast steel, unalloyed cast steel, low alloyed cast steel, martensitic
cast steel, stainless cast steel, heat-resistant cast steel, manganese cast steel
or a Ni-Cr cast iron. Due to its effect on compactability, the shape of the moderator
powder is preferably irregular. Furthermore, in the case where Fe is the main component
of the moderator powder, a powder size distribution of Fe is preferably between 45
µm and 150 µm. If Cr is the main component of the moderator powder, a powder size
of 63 µm is preferred.
[0012] The powder composition is inserted into the mold cavity in the form of compacted
inserts and/or coatings, for example. The powder composition can be inserted and positioned
so that it directly contacts the mold cavity wall(s), which encompass the mold's cavity.
The powder composition can also be inserted and positioned so that a distance between
the powder composition and the wall(s) of the mold cavity is maintained. Preferably,
a distance of 20 mm between the powder composition and the wall(s) of the mold cavity
is not exceeded and preferably a distance of at least 5 mm is maintained. By ensuring
a distance between the powder composition, in the form of compacted inserts, and the
mold cavity, the depletion of thermal energy from the SHS reaction front during carbide
formation by the mold material can be prevented and/or reduced. Furthermore, the powder
composition is positioned in areas of the mold cavity that relate to zones of the
casted component that should be reinforced. Options on how inserts and/or coatings
could be manufactured are known to those skilled in the art.
[0013] The positioning of casting inserts within the mold cavity can be achieved via an
assembly system, which can include such elements as metal wires, perforated metal
sheets, screws, nuts, washers etc. Said components are then utilized to manufacture
various ring and rail systems, for example, that thread the individual casting inserts
together via metals wires or rods to ensure a defined position of said inserts. Subsequently,
the casting inserts are fastened via metal bolts and/or screws, for example, to ensure
the defined positions are maintained during insertion.
[0014] For the construction of the utilized assembly systems, care must be taken when positioning
and placing the individual casting inserts, to ensure appropriate distance between
them. Due to high infiltration, the dimensions of the inserts may increase after the
in-situ SHS reaction, influencing the coalescence of the individual composite zones.
This can further lead to crack initiation and propagation during solidification and
post-casting heat treatments. To avoid this destructive phenomena, a minimal separation
distance of 5 mm, preferably 8 mm, between the casting inserts must be maintained,
Furthermore, after every fourth, preferably eighth, casting insert, the separation
distance should be increased to 10 mm, preferably 12 mm. A separation distance between
the casting inserts should not exceed 30 mm, preferably 25 mm.
[0015] Once the molten bulk material is cast into the mold and reaches the powder composition,
the synthesis reaction is initiated by point heating of the powders. The heat energy
of the liquid bulk material provides the activation energy to ignite the synthesis
reaction between the titanium and the carbon. This initiates the formation of titanium
carbides. This synthesis reaction is a highly exothermic combustion reaction that
generates heat and a combustion wave that passes through the powder composition, converting
the reactant powder to the titanium carbide product. It is therefore self-sustained
and consistently proceeds until the powder composition has completely reacted and/or
until the thermal dissipation rate from the reaction front exceeds the thermal generation
rate at the reaction front. Once the formation of titanium carbide phases is initiated,
they continue to nucleate, grow and eventually coalesce.
[0016] However, the high formation enthalpy of titanium carbide (-183 kJ/mol), which equates
to the highly exothermic nature of the formation reaction, results in a rapid temperature
increase at the reaction front. These high temperatures promote infiltration of the
molten bulk material between the individual titanium carbide phases. This is due,
for example, to reduced viscosity at elevated temperatures, which promotes the flow
of molten bulk material between the titanium carbide phases, ultimately separating
them and possibly transporting them away from their intended location within the cavity
mold towards the inner, main dimensions of the casted component. This separation of
the titanium carbides by the molten bulk material is known as destructive infiltration,
while the distribution of the titanium carbides away from the composite zone is known
as destructive fragmentation. Both phenomena are detrimental to the longevity of the
casted component. Not only are the mechanical properties, e.g. hardness, of the expected
composite zone diminished, the inclusion of hard and brittle titanium carbide phases
throughout the component can result in crack propagation, reducing the fracture toughness
and durability of the casted component.
[0017] Additionally, the heat liberated by the reaction and the associated elevated temperature
may be lost to local surroundings, leading to the evaporation of volatile components
and the dissociation of the resulting products. The emission and dissolution of such
gaseous products result in imminent risk of the formation of cavities and pores within
the intended composite zone. This further reduces the hardness and wear resistance
values, while also reducing the flexural strength of the component.
[0018] The moderator powder component of the powder composition absorbs and dissipates the
high heat energy produced during the SHS reaction of the titanium carbides, by melting.
This reduces the infiltration of the molten bulk material between the carbides and
hinders destructive fragmentation of the composite zone. Therefore, the moderator
powder plays a central role in stabilizing the composite zone. Furthermore, since
the moderator powder ultimately forms the matrix material within which the titanium
carbide phases are embedded, the mechanical properties of the matrix, and therefore
the chosen moderator powder, influence those of the resulting composite zone.
[0019] The ratio of reactant powder to moderator powder in the powder composition determines
the stability and hardness values of the resulting composite zone. With an insufficient
quantity of moderator powder, destructive fragmentation occurs and the locally targeted
mechanical properties are not achieved. If, however, the moderator powder content
exceeds stability requirements, the hardness values are not maximized, as the titanium
carbide content is too low. It is therefore critical to maintain the moderator powder
as low as possible in order to preserve the integrity of the composite zone while
maximizing the titanium carbide content and the therewith-associated hardness values.
[0020] According to the invention, the optimal ratio between the reactant powder and the
moderator powder is not an independent variable but is directly influenced by the
casting parameters during fabrication of the casted component. Most especially, the
destructive infiltration and fragmentation phenomena of the composite zone can be
manipulated by altering the geometry of the mold cavity. According to the invention,
by enlarging the mold cavity size and the resulting casted component, the amount of
moderator powder required to stabilize the composite zone can be reduced. This ensures
more titanium carbide phases can be produced, thereby increasing the overall hardness
of the composite zone.
[0021] The two main aspects that characterize the geometry of the mold cavity are the total
volume and the specific dimensions, i.e. shape, of the mold cavity.
[0022] The total volume of the mold cavity is commonly represented by the weight of the
molten bulk material to be poured into the mold cavity. The relationship between these
parameters is established via the density of the bulk material. However, due to the
inclusion of the powder composition within the mold cavity prior to pouring of the
molten bulk material, an effective mold cavity volume, which reflects the amount of
molten bulk material to be poured, can be calculated by subtracting the volume of
powder composition inserted into the mold cavity from the total mold cavity volume.
However, volume merely quantifies a three-dimensional space enclosed by a surface.
It can therefore not singularly provide sufficient information regarding the solidification
processes of the molten bulk material, as the distribution of this volume within the
mold cavity is also of consequence.
[0023] The volume distribution of molten bulk material within the mold cavity occurs due
to the specific shape or dimensions of said mold cavity. This can result in local
volumes that differ throughout the mold cavity, due to the form of the casted component.
The smallest of the three dimensions that define the local volume is known as the
wall thickness. Local volumes with smaller wall thickness values exhibit increased
cooling rates and shorted solidification rates. In comparison, local volumes with
larger wall thickness values exhibit decreased cooling rates and prolonged solidification
rates. This is a result of the associated heat transfer processes and paths, in addition
to the thermal conductivity and heat capacity properties of the molten bulk material
and/or the mold material, for example.
[0024] The local volume of interest, according to the invention, is a region of the mold
cavity that includes the powder composition. Therefore, the wall thickness according
to the invention is associated with the smallest value of the three dimensions that
define the local volume within a mold cavity containing the powder composition. It
is understood that the mold cavity can have various wall thickness values but preferably
exhibits only a singular value.
[0025] It can also be surmised that since the specific shape of the mold cavity defines
the distribution of the molten bulk material, other processes such as diffusion are
equally directed and governed by the dimensions of the mold cavity. The respective
transportation phenomena associated with diffusion, for example, are bounded by the
walls of the mold cavity and are accordingly directed and/or obstructed. As such,
a total thickness of the wall of the mold cavity, i.e. the wall thickness, permits
an enlarged diffusion path with increased size and does not provide the same amount
of containment as a smaller wall thickness could.
[0026] Together, the mold cavity volume, expressed as the weight of the molten bulk material
to be poured, and the mold cavity dimensions, more specifically the wall thickness,
influence the occurrence of destructive infiltration and fragmentation. The synergetic
relationship between wall thickness and total casting weight provides the means to
anticipate which mold cavity geometries will inherently lead to a reduction of necessary
moderator powder to stabilize the resulting composite zone. As such, according to
the invention, casting at least 30 kg, preferably at least 100 kg, of molten bulk
material into a mold cavity with a wall thickness of at least 40 mm requires a powder
composition consisting of 55-80 wt.% reactant powder and 20-45 wt.% moderator powder
to produce a casted component with composite zone.
[0027] According to a preferred further development of the method according to the invention,
when pouring at least 100 kg of molten bulk material into a mold cavity with a wall
thickness of at least 80 mm, a powder composition consisting of 60-80 wt.% reactant
powder and 20-40 wt.% moderator powder should be inserted into the mold cavity. In
this case, the molten bulk material can be a manganese steel or a martensitic steel.
[0028] According to another preferred further development of the method according to the
invention, when pouring at least 250 kg of molten bulk material into a mold cavity
with a wall thickness of at least 80 mm, a powder composition consisting 70-80 wt.%
reactant powder and 20-30 wt.% moderator powder should be inserted into the mold cavity.
In this case, the molten bulk material can be a manganese steel or a martensitic steel.
[0029] According to another preferred further development of the method according to the
invention, when pouring at least 600 kg of molten bulk material into a mold cavity
with a wall thickness of at least 85 mm, a powder composition consisting 60-80 wt.%
reactant powder and 20-40 wt.% moderator powder should be inserted into the mold cavity.
In this case, the molten bulk material can be a cast iron, grey cast iron or a white
chromium cast iron.
[0030] According to another preferred further development of the method according to the
invention, when pouring at least 800 kg of molten bulk material into a mold cavity
with a wall thickness of at least 50 mm, a powder composition consisting 55-70 wt.%
reactant powder and 30-45 wt.% moderator powder should be inserted into the mold cavity.
In this case, the molten bulk material can be a manganese steel or a martensitic steel.
[0031] Furthermore, the present invention also proposes a casted component for application
in a high wear industrial environment with a composite zone containing titanium carbides
in a matrix material, the composite zone formed in-situ during casting of molten bulk
material and obtained by using a powder composition comprising reactant powder, which
forms the titanium carbides within the composite zone and comprises titanium and carbon,
and moderator powder, which forms the matrix surrounding the titanium carbides within
the composite zone and comprises metal powders, characterized in that the bulk material
of the casted component weighs at least 30 kg, preferably at least 100 kg and the
casted component has a wall thickness of at least 40 mm.
[0032] The casted component comprises a bulk material, which forms the main dimensions of
the component, and a composite zone, which is located at the periphery of the component.
The periphery refers to an outer surface of the component, which is in direct contact
with the surrounding environment, and/or a near surface region, which lies beneath
the outer surface of the component without necessarily contacting said outer surface.
Preferably, a near surface region remains distant from the main dimensions of the
component and is surrounded by casted bulk material.
[0033] The bulk material is a metallic material, based on iron, nickel or cobalt. Preferably,
the bulk material is an iron alloy containing carbon, chromium, manganese and/or silicon.
Most preferably, the bulk material is unalloyed cast steel, low alloyed cast steel,
a manganese cast steel, a martensitic cast steel, a cast iron, a grey cast iron, or
a white chromium cast iron. It is understood that impurities related to the manufacturing
of the bulk material, regardless if a pure metal or an industrial alloy, are to be
disregarded, as their inclusion within the material is not intentional nor is their
removal economically feasible. Such impurities are commonly referred to as incidental
impurities and can include sulfides, oxides and nitrides, such as MnS, Al
2O
3, TiN, respectfully, and/or elements such as S, P, Ti, Al and/or Ca.
[0034] The composite zone is a region of the component that contains at least one type of
phase that chemically and/or physically differs from that of the bulk material and
does not originate from the bulk material. Furthermore, this phase also chemically
and/or physically differs from the matrix material with which it is surrounded. The
composite zone according to the invention contains at least titanium carbide, preferably
only titanium carbide, as the ceramic phase.
[0035] The matrix material and the bulk material are preferably not the same material. The
matrix material is preferably a metallic material and contains at least one metal
from the group of Fe, Co, Ni, Mo, Cr, W, Al, Mn, or Cu, preferably comprising at least
two of these metals. Preferably, the matrix material contains Fe, Mn, Si and C, most
preferably also containing Cr powder. Most preferably, the matrix material has a chemical
composition associated with a grey cast iron, white cast iron, chromium cast iron,
chromium cast steel, unalloyed cast steel, low alloyed cast steel, manganese cast
steel or a Ni-Cr cast iron.
[0036] It is preferable that the amount of titanium carbide within the composite zone is
at least 40 vol.%, preferably at least 50 vol.%, more preferably at least 60 vol.%
and most preferably at least 70 vol. %. The remaining volume within the composite
zone contains the matrix material. It is understood that bulk material may also be
contained within the composite zone. Preferably, the amount of bulk material is below
60 vol.%, more preferably below 40 vol.%, even more preferably below 20 vol.% and
most preferably below 10 vol.%. The boundary between the composite zone and the main
dimensions of the casted component are defined by an amount of titanium carbide below
40 vol. %.
[0037] The composite zone manifests globular titanium carbide phases that are preferably
coalesced together, forming what can be considered a scaffold, or spider web, of titanium
carbide phases. It is understood that said scaffold can also be composed of individual
titanium carbide phases clustered together, so that they are directly adjacent to
one another yet remain separate phases. This scaffold interconnects the individual
titanium carbides phases, most preferably all of the titanium carbide phases within
the composite zone, while the matrix material is located in the interspatial regions
formed by the titanium carbide scaffold. Such a scaffold hinders crack propagation,
due to its blocking and redirecting effect. Furthermore, by preventing individual
titanium carbide phases from presenting within the matrix material, the risk of cracking
and chipping of the composite zone can be reduced. Therefore, the matrix material
preferably manifests a limited amount, most preferably zero, individual titanium carbide
phases. A composite zone as described above can be considered to display a lake-landscape
or "foam on water"-like appearance, when imaged using an optical light microscope
or a scanning electron microscope, for example.
[0038] Preferably, a casted component as described above is a hammer, a blow bar, a roller,
a cone, a mantle, a plate, a screen liner, teeth, a chute or a duct.
[0039] According to a further development, a casted component with a wall thickness of at
least 80 mm and a manganese steel or martensitic steel bulk material weighting at
least 100 kg.
[0040] According to another further development, a casted component with a wall thickness
of at least 80 mm and a manganese steel or martensitic steel bulk material weighting
at least 250 kg.
[0041] According to another further development, a casted component with a wall thickness
of at least 85 mm and a cast iron, grey cast iron or a white chromium cast iron bulk
material weighting at least 600 kg.
[0042] According to another further development, a casted component with a wall thickness
of at least 40 mm and a manganese steel or martensitic steel bulk material weighting
at least 800 kg.
[0043] The present invention is further detailed in the following specific examples in connection
with correlating figures. The corresponding specific description clarifies further
details, features and advantages of the present invention. The figures below include:
Figure 1: A schematic representation of a casted jaw (A), including a perspective
view of a utilized casting insert (B) and a section of an implemented assembly system
(C), in addition to the insertion location of said assembly system in a mold cavity
(D) and the resulting location of composite zones within the casted jaw component
(D).
Figure 2: A schematic representation of a cast mantle (A), a cross-sectional view
of the cast mantle wall illustrating the location of the produced composite zones
(B), and an assembly system for positioning and inserting the casting inserts (C &D)
into a corresponding mold cavity (E).
Figure 3: A schematic representation of a cast cone (A), a cross-sectional view of
the cast cone wall illustrating the location of the produced composite zones (B),
and an assembly system for positioning and inserting the casting inserts (C &D) into
a corresponding mold cavity (E).
Figure 4: A schematic representation of a cast roller (A), a cross-sectional view
of the cast roller wall illustrating the location of the produced composite zones
(B), and ring implemented for constructing an assembly system for positioning and
inserting the casting inserts (C) into a corresponding mold cavity (D).
Figure 5: Scanning electron micrographs of the upper composite zone of a roller casted
implementing a powder composition comprising 75 wt.% reactant powder and 25 wt.% moderator
powder according to example 4 (A to D) and of the transisional area between the composite
zone and the bulk material (E).
Figure 6: A schematic representation of a cast blow bar (A), a cross-sectional view
of the cast roller wall illustrating the location of the produced composite zones
(B), and a section of an assembly system implemented for positioning and inserting
the casting inserts in a mold cavity(C).
Figure 7: Scanning electron micrographs of the composite zone of a blow bar casted
implementing a powder composition comprising 70 wt.% reactant powder and 30 wt.% moderator
powder according to example 5 (A and B).
Figure 8: A schematic representation of a cast hammer (A), a cross-sectional view
of the cast hammer wall illustrating the location of the produced composite zones
(B), and a section of an assembly system implemented for positioning and inserting
the casting inserts in a mold cavity(C).
Example 1
[0044] As described in detail below, this example aims to produce a jaw component 100, as
shown in Figure 1A, for a jaw crusher and reinforced with titanium carbide composite
zones.
[0045] A powder composition is produced by mixing a 70 wt.% reactant powder with 30 wt.%
moderator powder. The reactant powder contains titanium sponge powder, which is manufactured
by hydrogenation-dehydrogenation and is composed of at least 99 at.% Ti and maximally
0.4 at.% O and 0.03 at.% H, and flake graphite, which is composed of at least 96 at.%
C and maximally 0.05 at.% S. Both the titanium and carbon powders manifest irregular
shapes and exhibit an average diameter of 35 µm and 5-10 µm, respectively. The ratio
of titanium powder to carbon powder is 45 at.% to 55 at. %C. The moderator powder
has the composition of a manganese steel with 21 wt.% Mn and Fe, Si, and C. Furthermore,
the minor inclusion of other elements due to the use of ferroalloys to fabricate the
moderator powder cannot be excluded.
[0046] The powders are subsequently mixed, dried and compressed by uniaxial cold pressing
under a compaction pressure of 500 MPa or isostatically under a pressure of 200 MPa,
to obtain 136 casting inserts 101 with dimensions of 20 x 20 x 100 mm.
[0047] The produced casting inserts 101 are subsequently provided with two through-holes
102 via a conventional drilling means, as shown in Figure 1B, in order to construct
seventeen assembly systems 103 for placement within a mold cavity. A section of an
assembly system 103 is illustrated in Figure 1C, each assembly system 103 consisting
of eight casting inserts 101 positioned at a separation distance of 8 mm from another
and fixed to the same perforated metal sheet 104 via screws 105. Thereupon, the assembly
systems 103 are placed and positioned in a mold cavity 106 of a sand mold, a cross-section
of which is illustrated in Figure 1D, at locations associated with the highest wear
expectation of the jaw component 100, i.e. at the vertexes 107 of the jaw teeth. The
wall thickness 108 of the vertex 102 associated with the tooth width is 40 mm while
the wall thickness 109 of the vertex 102 associated with the tooth root is 40 mm.
[0048] A molten bulk material consisting of a manganese steel containing 12 wt. % Mn and
a weight of 800 kg is poured into the mold cavity. The thermal energy of the molten
steel initiates a self-propagating high temperature synthesis (SHS) reaction between
the titanium and carbon components of the powder composition. The moderator powder
melts, thereby dissipating the produced heat energy and preventing infiltration of
the molten bulk material and subsequent destructive fragmentation.
[0049] As illustrated in a section of a cross-sectional view of a casted jaw component 100
in Figure 1D, the produced composite zones 110 exhibit globular titanium carbide phases
homogenously distributed within matrix material comprising a manganese steel with
21 wt.% Mn and Fe, Si, and C. The bulk material 111 of the jaw component 100, which
surrounds the composite zones 110, manifests a softer austenitic microstructure composed
of a manganese cast steel.
[0050] Mechanical properties of the composite zone 110 and the bulk material 111 were measured,
the results of which are presented in Table 1 below. Hardness values were obtained
via the Vickers hardness test with a load of 294.3 N for a hold time of 10 seconds.
Ten measurements were conducted for each testing locations, the results of which were
averaged. The tests to determine the resistance to abrasive wear, i.e. dry-sliding
wear, were determined utilizing the ball-on-disc method according to ISO 20808:2004.
Said tests were conducted with an Ebit Polska Tribometer in a friction pair system
utilizing a corundum ball component with a diameter of 3.175 mm. Further testing parameters
include a friction radius of approximately 3.5 mm, a disc speed of 192 RPM, a testing
load of 10 N and a friction path of 704 m. After the ball-on-disc tests were undergone,
three-dimensional scans of the samples as well as depth measurements of the cross-sections
of the produced tracks enabled the determination of the wear index.
Table 1: Hardness and wear properties of the composite zone and bulk material of the
jaw component.
Casted Component |
Testing Location |
Vickers Hardness [HV30] |
Wear Index *10-9 [µm3/N*m] |
Jaw 100 |
composite zone 110 |
670.00 |
6.80 |
bulk material 111 |
242.70 |
85.90 |
[0051] As exemplified in Table 1, the composite zones 110 of the jaw component 100 manifest
over twice the hardness and almost fifteen times the wear resistance of the surrounding
bulk material 111.
Example 2
[0052] Example 2 relates to a casted mantle component 200, as shown in Figure 2A, which
is produced so as to exhibit areas reinforced with titanium carbides for suitable
application in a cone crusher. As the cross-sectional view of the mantle wall 201
in in Figure 2B illustrates, as sectioned from the corresponding circle in Figure
2A, the mantle 200 is reinforced with three titanium carbide composite zones, an upper
composite zone 202, a lower inner composite zone 203, both located at the inner circumference
of the mantle wall 201, and a lower outer composite zone 204..
[0053] A powder composition for the upper composite zone 202 is produced by mixing 60 wt.
% reactant powder with 40 wt.% moderator powder. The reactant powder contains titanium
sponge powder, which is manufactured by hydrogenation-dehydrogenation and is composed
of at least 99 at.% Ti and maximally 0.4 at.% O and 0.03 at.% H. The reactant powder
also contains flake graphite, which is composed of at least 99 at.% C and maximally
0.05 at.% S. Both the titanium and carbon powders manifest irregular shapes and exhibit
an average diameter of 35 µm and between 5-10 µm, respectively. The ratio of titanium
powder to carbon powder is 45 at.% Ti to 55 at.% C. The moderator powder has the composition
of a manganese steel with 21 wt.% Mn and Fe, Si, and C. Furthermore, the minor inclusion
of other elements due to the use of ferroalloys to fabricate the moderator powder
cannot be excluded.
[0054] A powder composition for the lower inner composition zone 203 is produced by mixing
63 wt. % reactant powder with 37 wt.% moderator powder. The specifics to the composition,
size, form and production of both the reactant powder and the moderator powder are
identical to that of the powder composition for the upper composite zone 202, detailed
above. The ratio of titanium powder to carbon powder is also 45 at.% Ti to 55 at.%
C. The moderator powder also has the composition of a manganese steel with 21 wt.%
Mn and Fe, Si, and C, with possible minor inclusion of other elements, due to the
selected powder manufacturing method.
[0055] A powder composition for the lower outer composition zone 204 is produced by mixing
60 wt. % reactant powder with 40 wt.% moderator powder. The specifics to the composition,
size, form and production of both the reactant powder and the moderator powder are
identical to that of the powder composition for the upper composite zone 202, detailed
above. The ratio of titanium powder to carbon powder is also 45 at.% Ti to 55 at.%
C. The moderator powder also has the composition of a manganese steel with 21 wt.%
Mn and Fe, Si, and C, with possible minor inclusion of other elements, due to the
selected powder manufacturing method.
[0056] Each of the three powders are subsequently mixed, dried and compressed by uniaxial
cold pressing under a compaction pressure of 500 MPa or isostatically under a pressure
of 200 MPa, to obtain a total of 371 casting inserts 205 with dimensions of 20 x 20
x 100 mm. Of these 289 casting inserts, 115 are composed of the powder for the upper
composite zone 202, 128 are composed of the powder for the lower inner composite zone
203 and 128 are composed of the powder for the lower outer composite zone 204.
[0057] The casting inserts 205 are inserted into the mold cavity of a sand mold via an assembly
system 206, as shown in Figure 2C. An enlarged section of the assembly system 206
is shown in Figure 2D. The assembly system 206 comprises three separate rings, and
upper ring 207, a lower inner ring 208 and a lower outer ring 209, each corresponding
to the upper composite zone 202, the lower inner composite zone 203 and the lower
outer composite zone 204, respectively. The upper ring 207, a lower inner ring 208
and a lower outer ring 209 each consist of 115, 128 and 128 casting inserts 205, respectively.
The casting inserts 205, which each exhibit two through-holes , are threaded by two
rods 210 to build each of the three rings of the assembly system 206. During threading
and positioning of the casting inserts 205 on the rods 210, a separation distance
of 8 mm is maintained between each casting insert 205. Furthermore, after every ninth
casting insert 205, the separation distance is increased to 10 mm.
[0058] The constructed assembly system 206 is then inserted into the mold cavity 211 of
the sand mold at a location associated with the highest wear expectation of the cone
crusher. As shown in Figure 2E, during installation of the assembly system 206 into
the mold cavity 211, both the lower inner ring 208 and the upper ring 207 are placed
at a position 10 mm from the inner mold cavity wall. Furthermore, the lower outer
ring 209 is positioned at a distance of 10 mm from the lower inner ring 208, which
distance is maintained by spacers that exhibit identical material properties as the
rods 220 implemented in the assembly system 206.
[0059] The wall thickness 212 of the mold cavity 211 associated with the upper ring 207
and the lower rings 208;209 is 90 mm and 80 mm, respectively, as shown in Figure 2E.
[0060] A molten bulk material consisting of a manganese steel containing 13 wt. % Mn and
exhibiting a weight of 1005 kg is poured into the mold cavity 211. The thermal energy
of the molten steel initiates a self-propagating high temperature synthesis (SHS)
reaction between the titanium and carbon components of the powder composition. The
moderator powder melts, thereby dissipating the produced heat energy and preventing
infiltration of the molten bulk material and subsequent destructive fragmentation.
[0061] As a result, three composite zones 202, 203 and 204, each containing globular titanium
carbide within matrix material comprising a manganese steel with 21 wt.% Mn and Fe,
Si, and C. within an austenitic bulk material 212 are fabricated, as depicted in Figure
2B.
[0062] The bulk material 213 of the mantle component 200, which surrounds the composite
zones 202, 203 and 204, manifests a softer austenitic microstructure composed of a
manganese cast steel, as given in Table 2 below. Mechanical properties of the composite
zones 202; 203; 204 and the bulk material 213 of the mantle component 200 were measured
analogous to the testing methods as described for the jaw component 100 in example
1.
Table 2: Hardness and wear properties of the composite zones and bulk material of
the mantle component.
Casted Component |
Testing Location |
Vickers Hardness [HV30] |
Wear Index *10-9 [µm3/N*m] |
Mantle 200 |
Upper composite zone 202 |
562.00 |
7.40 |
Lower outer composite zone 204 |
560.0 |
7.40 |
inner outer composite zone 203 |
645.00 |
6.50 |
bulk material 213 |
244.50 |
90.46 |
Example 3
[0063] In this example, the aim is to produce a cone 300, as shown in Figure 3A, reinforced
with titanium carbide containing composite zones.
[0064] Figure 3B, which depicts a cross-sectional view of the cone wall 301, as sectioned
via the circle in Figure 3A, shows that the cone 300 is reinforced with three titanium
carbide composite zones, an upper composite zone 302, a lower inner composite zone
303 and a lower outer composite zone 304, at the outer circumference of the cone wall
301.
[0065] A powder composition for the upper composite zone 302 is produced by mixing 60 wt.
% reactant powder with 40 wt.% moderator powder. The reactant powder contains titanium
sponge powder, which is manufactured by hydrogenation-dehydrogenation and is composed
of at least 99 at.% Ti and maximally 0.4 at.% O and 0.03 at.% H, and flake graphite,
which is composed of at least 99 at.% C and maximally 0.05 at.% S. Both the titanium
and carbon powders manifest irregular shapes and exhibit an average diameter of 35
µm and 5-10 µm, respectively. The ratio of titanium powder to carbon powder is 45
at.% Ti to 55 at.% C. The moderator powder has the composition of a manganese steel
with 21 wt.% Mn and Fe, Si, and C. Furthermore, the minor inclusion of other elements
due to the use of ferroalloys to fabricate the moderator powder cannot be excluded.
[0066] A powder composition for the lower inner composition zone 303 is produced by mixing
63 wt. % reactant powder with 37 wt.% moderator powder. The specifics to the composition,
size, form and production of both the reactant powder and the moderator powder are
identical to that of the powder composition for the upper composite zone 201, detailed
above. The ratio of titanium powder to carbon powder is also 45 at.% Ti to 55 at.%
C. The moderator powder also has the composition of a manganese steel with 21 wt.%
Mn and Fe, Si, and C, with possible minor inclusion of other elements, due to the
selected powder manufacturing method.
[0067] A powder composition for the lower outer composition zone 304 is produced by mixing
60 wt. % reactant powder with 40 wt.% moderator powder. The specifics to the composition,
size, form and production of both the reactant powder and the moderator powder are
identical to that of the powder composition for the upper composite zone 301, detailed
above. The ratio of titanium powder to carbon powder is also 45 at.% Ti to 55 at.%
C. The moderator powder also has the composition of a manganese steel with 21 wt.%
Mn and Fe, Si, and C, with possible minor inclusion of other elements, due to the
selected powder manufacturing method.
[0068] Each of the three powders are subsequently mixed, dried and compressed by uniaxial
cold pressing under a compaction pressure of 500 MPa or isostatically under a pressure
of 200 MPa, to obtain a total of 289 casting inserts 306 with dimensions of 20 x 20
x 100 mm. Of these 371 casting inserts 306, 87 are composed of the powder for the
upper composite zone 302, 101 are composed of the powder for the lower inner composite
zone 303 and 101 are composed of the powder for the lower outer composite zone 304.
[0069] Subsequently, the casting inserts 306 are provided with through-holes to construct
an assembly system 307, for the ensuring insertion and positioning of said casting
inserts 306 in a sand mold. As depicted in Figures 3C and 3D, the assembly system
307 comprises three separate rings, an upper ring 308, a lower inner ring 309 and
a lower outer ring 310, ultimately corresponding to the upper composite zone 302,
the lower inner composite zones 303 and the lower outer composite zone 304, respectively.
The casting inserts 306 of each individual ring, are each threaded by two rods 311
to build the corresponding ring of the assembly system 307. During threading and positioning
of the casting inserts 306 on the rods 311, a separation distance of 8 mm is maintained
between each casting insert 306. Furthermore, after every ninth casting insert 306,
the separation distance is increased to 10 mm. The separation distance pattern between
the casting inserts 306 is illustrated in Figures 3C and 3D. Furthermore, , the two
lower rings 309;310 of the assembly system 307 are separated by spacers, which exhibit
identical dimensions and material properties as the rods 311 with which the casting
inserts 306 are threaded.
[0070] The constructed assembly system 307 is then inserted into a mold cavity 312 of the
sand mold at a location associated with the highest wear expectation of the cone.
As shown in Figure 3E, during installation of the assembly system 307 into the mold
cavity 312, all three rings are placed at a position 10 mm from the mold cavity wall.
The wall thickness 313 of the mold cavity associated with the upper 308 and lower
309; 310 rings is 70 mm and 95 mm, respectively.
[0071] A molten bulk material consisting of a manganese steel containing 13 wt. % Mn and
a weight of 840 kg is poured into the mold cavity 312. The thermal energy of the molten
steel initiates a self-propagating high temperature synthesis (SHS) reaction between
the titanium and carbon components of the powder composition. The moderator powder
melts, thereby dissipating the produced heat energy and preventing infiltration of
the molten bulk material and subsequent destructive fragmentation.
[0072] As a result, three composite zones 302, 303, and 304, each containing titanium carbide
within matrix material comprising a manganese steel with 21 wt.% Mn and Fe, Si, and
C, within an austenitic bulk material 314 are fabricated, as depicted in Figure 3B.
This results in a harder zone of the cone 300 where the powder composition was originally
placed.
[0073] The bulk material 314 of the cone component 300, which surrounds the composite zones
302, 303 and 304, manifests a softer austenitic microstructure composed of a manganese
cast steel, as given in Table 3 below. Mechanical properties of the composite zones
302; 303; 304 and the bulk material 314 of the mantle component 300 were measured
analogous to the testing methods as described for the jaw component 100 in example
1.
Table 3: Hardness and wear properties of the composite zones and bulk material of
the cone component.
Casted Component |
Testing Location |
Vickers Hardness [HV30] |
Wear Index *10-9 [µm3/N*m] |
Cone 300 |
Upper composite zone 302 |
570.07 |
6.87 |
Lower outer composite zone 304 |
563.00 |
6.87 |
Inner outer composite zone 303 |
661.00 |
5.66 |
Bulk material 314 |
244.50 |
90.46 |
Example 4
[0074] The production of a casted roller 400, as shown in Figure A, is described in detail
in the following. A cross-section of the roller wall 401, as taken from the section
circle in Figure 4A and depicted in Figure 4B, illustrates the roller 400 exhibits
two composite zones containing titanium carbide, namely an upper composite zone 402
and a lower composite zone 403.
[0075] A powder composition for the upper composite zone 402 is produced by mixing 75 wt.
% reactant powder with 25 wt.% moderator powder. The reactant powder contains titanium
sponge powder, which is manufactured by hydrogenation-dehydrogenation and is composed
of at least 99 at.% Ti and maximally 0.4 at.% O and 0.03 at.% H, and flake graphite,
which is composed of at least 99 at.% C and maximally 0.05 at.% S. Both the titanium
and carbon powders manifest irregular shapes and exhibit an average diameter of 35
µm and 5-10 µm, respectively. The ratio of titanium powder to carbon powder is 45
wt.% to 55 wt. %C. The moderator powder has the composition of a high chromium cast
iron with 16.0 wt.% Cr, 3.0 wt.% C, 0.6 wt.% Si, 0.7 wt.% Mn, 0.2 wt.% Ni, 2.0 wt.%
Mo, rest wt.% is Fe. Furthermore, the minor inclusion of other elements due to the
use of ferroalloys to fabricate the moderator powder cannot be excluded.
[0076] A powder composition for the lower composite zone 403 is produced by mixing 75 wt.
% reactant powder with 25 wt.% moderator powder. The specifics to the composition,
size, form and production of both the reactant powder and the moderator powder are
identical to that of the powder composition for the upper composite zone 201, detailed
above. The ratio of titanium powder to carbon powder is also 45 at.% Ti to 55 at.%
C. The moderator powder also has the composition of a manganese steel with 21 wt.%
Mn and Fe, Si, and C, with possible minor inclusion of other elements, due to the
selected powder manufacturing method.
[0077] Each of the two powders are subsequently mixed, dried and compressed by uniaxial
cold pressing under a compaction pressure of 500 MPa or isostatically under a pressure
of 200 MPa, to obtain a total of 289 casting inserts 404 with dimensions of 15 x 20
x 100 mm. Of these 238 casting inserts, 120 are composed of the powder for the upper
composite zone 402 and 118 are composed of the powder for the lower composite zone
403.
[0078] Utilizing the produced casting inserts 404, an assembly system 4 comprising two separate
rings 405, and example of which is shown in Figure 4C is fashioned. Said assembly
system is similarly constructed as those assembly systems 206; 307 implemented for
the mantle 200 and cone 300 components, as described above. Consequently, the two
rings 405 relate to the upper 402 and lower 403 composite zones formed during casting
of the roller 400. Furthermore, during threading and positioning of the individual
casting inserts 404, a separation distance of 8 mm is maintained between each casting
insert while the separation distance after every ninth casting insert is increased
to 10 mm. The separation distance pattern between the casting inserts 404 is illustrated
in Figures 4C.
[0079] The assembly system is then subsequently inserted into a mold cavity 406 of a sand
mold at a location associated with the highest wear expectation of the roller 400;
see Figure 4D. During installation of the assembly system into the mold cavity 406,
both rings 405 are fixed to the mold cavity walls so that the casting inserts 404
of the respective rings 405 are in direct contact with the mold cavity wall. The wall
thickness 407 of the mold cavity 406 associated with the upper and lower rings 405
is 60 mm and 70 mm, respectively.
[0080] Finally, a molten bulk material consisting of a chromium cast iron containing 15
wt.% Cr and exhibiting a weight of 850 kg is poured into the mold cavity 406. The
thermal energy of the molten steel initiates a self-propagating high temperature synthesis
(SHS) reaction between the titanium and carbon components of the powder composition.
The moderator powder melts, thereby dissipating the produced heat energy and preventing
infiltration of the molten bulk material and subsequent destructive fragmentation.
[0081] Consequently, two composite zones 402; 403, each containing titanium carbide phases
within a high chromium cast iron matrix material and a manganese steel with 21 wt.%
Mn matrix material, respectively, are fabricated. Furthermore, both composite zones
402; 403 are partially surrounded by a chromium cast iron with 15 wt.% Cr, which realizes
the bulk material of the cast roller 400 component.
[0082] Microstructural micrographs, as obtained from a scanning electron microscope (SEM),
of the upper composite zone 402 of the roller 400, are illustrated in Figure 5. The
titanium carbide phases, which are designated with the label "TiC", are globular in
shape and exhibit a strong network-skeleton, due to their local coalescence to each
other in the matrix phase. Furthermore, the matrix material, i.e. the high chromium
cast iron, forms individual "lake-like" formations that do not contain individual
titanium carbide phases, but are surrounded by a TiC carbides network. Furthermore,
Figure 5E displays the transition area between the composite zone and the chromium
cast iron bulk material.
[0083] Mechanical properties of the composite zones 402; 403 and the bulk material of the
roller component 400 were measured analogous to the testing methods as described for
the jaw component 100 in example 1.
Table 4: Hardness and wear properties of the composite zones and bulk material of
the roller component.
Casted Component |
Testing Location |
Vickers Hardness [HV30] |
Wear Index *10-9 [µm3/N*m] |
Roller 400 |
Upper composite zone 402 |
1076.10 |
3.59 |
Lower outer composite zone 403 |
989.00 |
3.59 |
Bulk material |
537.00 |
6.00 |
Example 5
[0084] As Figure 6A exhibits, the aim of this example is to produce a blow bar 500 reinforced
with titanium carbide composite zones 501, as shown in Figure 6B. Figure 6B, which
is a he cross-sectional view of the blow bar 500 taken along the section line X_X
in Figure 6A, illustrates two double rows of composite zones 501 parallel to the length
of the blow bar 500.
[0085] A powder composition is produced by mixing a 70 wt.% reactant powder with 30 wt.%
moderator powder. The reactant powder contains titanium sponge powder, which is manufactured
by hydrogenation-dehydrogenation and is composed of at least 99 at.% Ti and maximally
0.4 at.% O and 0.03 at.% H, and flake graphite, which is composed of at least 96 at.%
C and maximally 0.05 at.% S. Both the titanium and carbon powders manifest irregular
shapes and exhibit an average diameter of 35 µm and 5-10 µm, respectively. The ratio
of titanium powder to carbon powder is 45 at.% to 55 at. %C. The moderator powder
has the composition of a martensitic cast steel with 4,5 wt.% Cr and Fe, Mn, Si, and
C. Furthermore, the minor inclusion of other elements due to the use of ferroalloys
to fabricate the moderator powder cannot be excluded.
[0086] The powders are subsequently mixed, dried and compressed via cold uniaxial pressing
under a compaction pressure of 500 MPa or isostatically under a pressure of 200 MPa,
to obtain 80 casting inserts 502 with dimensions of 18 x 20 x 100 mm.
[0087] These casting inserts 502 are then inserted into a mold cavity of a sand mold via
an assembly system 503, illustrated in Figure 6C. The assembly system 503 encompasses
two double rows of casting inserts 502 placed on the top and bottom surfaces of a
rail 504 and fixed thereupon with screws 505, which are inserted through two through-holes
of each casting insert 502. During positioning of the casting inserts 502, a separation
distance of 8 mm is maintained between them. Each singular row of casting inserts
contains 20 individual casting inserts 502. The assembly system 503 is then inserted
into the mold cavity at a distance of 10 mm from the mold cavity wall. The wall thickness
if said location is 80 mm. A molten bulk material consisting of a martensitic cast
steel 3 wt.% Cr and a weight of 280 kg is poured into the mold cavity. The thermal
energy of the molten steel initiates a self-propagating high temperature synthesis
(SHS) reaction between the titanium and carbon components of the powder composition.
The moderator powder melts, thereby dissipating the produced heat energy and preventing
infiltration of the molten bulk material and subsequent destructive fragmentation.
[0088] Consequently and as shown in the scanning electron micrographs presented in Figure
7, a composite zone 501 containing titanium carbide phases (TiC) within a martensitic
cast steel matrix material is fabricated. As a result of coalescence, the titanium
carbide phases are globular und manifest a network-skeleton within which the martensitic
cast steel matric material forms individual "lake-like" formations. As shown, these
formations rarely contain individual titanium carbide phases therein, bur are rather
surrounded by the titanium carbide network skeleton.
[0089] Furthermore, as the mechanical property values presented in Table demonstrate, the
area of the cast blow bar 500 that contains the composite zone 501 is harder and exhibits
a higher wear resistance than that of the surrounding martensitic bulk material. Said
mechanical properties were measured analogous to the testing methods as described
for the jaw component 100 in example 1.
Table 5: Hardness and wear properties of the composite zones and bulk material of
the blow bar component.
Casted Component |
Testing Location |
Vickers Hardness [HV30] |
Wear Index *10-9 [µm3/N*m] |
Blow bar 500 |
Composite zone 501 |
885.00 |
4.47 |
Bulk material |
515.00 |
26.57 |
Example 6
[0090] In this example, the aim is to produce a hammer 600 reinforced with titanium carbide
based composite zones 601. As the cross-sectional view in Figure 8B shows, which is
taken along the X-X section line in Figure 8A, the hammer 600 manifests four composite
zones 601 within its lower corners, each corner exhibiting two composite zones 601
oriented orthogonal to each other.
[0091] A powder composition is produced by mixing a 65 wt.% reactant powder with 35 wt.%
moderator powder. The reactant powder contains titanium sponge powder, which is manufactured
by hydrogenation-dehydrogenation and is composed of at least 99 wt.% Ti and maximally
0.4 wt.% O and 0.03 wt.% H, and flake graphite, which is composed of at least 96 wt.%
C and maximally 0.05 wt.% S. Both the titanium and carbon powders manifest irregular
shapes and exhibit an average diameter of 35 µm and 5-10 µm, respectively. The ratio
of titanium powder to carbon powder is 45 at.% to 55 at.%C. The moderator powder has
the composition of a martensitic cast steel with 10 wt.% Cr and Fe, Mn, Si, and C.
Furthermore, the minor inclusion of other elements due to the use of ferroalloys to
fabricate the moderator powder cannot be excluded.
[0092] The powders are subsequently mixed, dried and compressed via cold uniaxial pressing
under a compaction pressure of 500 MPa or isostatically under a pressure of 200 MPa,
to obtain 36 casting inserts 602 with dimensions of 30 x 20 x 100 mm.
[0093] Prior to insertion into the mold cavity of a sand mold, the casting inserts 602,
which each exhibit two through-holes, are threaded together via screws 605 and fixed
to perforated metal sheets 604, see Figure 8C, which displays a section of said assembly
system. During positioning, a separation distance of 8 mm is maintained between the
casting inserts 602, with this distance increasing to 10 mm after every fourth casting
insert 602. The constructed assembly system 603 is then placed in the sand mold at
a location associated with the highest wear expectation at a distance of 5 mm from
the mold cavity wall. The wall thickness of said location is 80 mm.
[0094] .A molten bulk material consisting of a martensitic cast steel 10 wt.% Cr and a weight
of 100 kg is poured into the mold cavity. The thermal energy of the molten steel initiates
a self-propagating high temperature synthesis (SHS) reaction between the titanium
and carbon components of the powder composition. The moderator powder melts, thereby
dissipating the produced heat energy and preventing infiltration of the molten bulk
material and subsequent destructive fragmentation. As a result, a composite zone 601
containing titanium carbide within matrix material comprising a martensitic cast steel
with 10 wt.% Cr and Fe, Mn, Si, and C is fabricated. As shown by the mechanical properties
listed in Table 6 below,this results in a harder and more wear resistance area of
the hammer component 600 in comparison to the martensitic bulk material Said mechanical
properties were measured analogous to the testing methods as described for the jaw
component 100 in example 1.
Table 6: Hardness and wear properties of the composite zones and bulk material of
the hammer component.
Casted Component |
Testing Location |
Vickers Hardness [HV30] |
Wear Index *10-9 [µm3/N*m] |
Hammer 600 |
Composite zone |
829.00 |
5.35 |
Bulk material |
480.00 |
37.00 |
List of Reference Numerals
[0095]
- 100
- Jaw
- 101
- Casting insert
- 102
- Through-hole
- 103
- Assembly System
- 104
- Metal sheet
- 105
- Screw
- 106
- Mold cavity
- 107
- Vertex
- 108
- Wall thickness
- 109
- Wall thickness
- 101
- Composite zone
- 111
- Bulk material
- 200
- Mantle
- 201
- Mantle wall
- 202
- Upper composite zone
- 203
- Lower, inner composite zone
- 204
- Lower, outer composite zone
- 205
- Casting insert
- 206
- Assembly system
- 207
- Upper ring
- 208
- Lower inner ring
- 209
- Lower outer ring
- 210
- Rod
- 211
- Mold cavity
- 212
- Wall thickness
- 213
- Bulk material
- 300
- Cone
- 301
- Cone wall
- 302
- Upper composite zone
- 303
- Lower inner composite zone
- 304
- Lower outer composite zone
- 305
- Cone wall
- 306
- Casting insert
- 307
- Assembly system
- 308
- Upper ring
- 309
- Lower inner ring
- 310
- Lower outer ring
- 311
- Rod
- 312
- Mold cavity
- 313
- Wall thickness
- 314
- Bulk material
- 400
- Roller
- 401
- Roller wall
- 402
- Upper composite zone
- 403
- Lower composite zone
- 404
- Casting insert
- 405
- Ring
- 406
- Mold cavity
- 407
- Wall thickness
- 500
- Blow Bar
- 501
- Composite zone
- 502
- Casting insert
- 503
- Assembly system
- 504
- Rail
- 505
- Screw
- 600
- Hammer
- 601
- Composite zone
- 602
- Casting insert
- 603
- Assembly system
- 604
- Metal sheet
- 605
- Screw
1. A method for casting a component for application in a high wear industrial environment
with a composite zone containing titanium carbides in a matrix material, the composite
zone formed in-situ during casting of molten bulk material and obtained by using a
powder composition comprising reactant powder, which forms the titanium carbides within
the composite zone and comprises titanium and carbon, and moderator powder, which
forms the matrix surrounding the titanium carbides within the composite zone and comprises
metal powders, characterized in that a powder composition consisting of 55-80 wt.% reactant powder and 20-45 wt.% moderator
powder is inserted into a mold cavity with a wall thickness of at least 40 mm and
at least 30 kg, preferably at least 100 kg of molten bulk material is poured into
the mold cavity.
2. A method for casting a component according to claim 1, characterized in that a powder composition consisting of 60-80 wt.% reactant powder and 20-40 wt.% moderator
powder is inserted into a mold cavity with a wall thickness of at least 80 mm and
at least 100 kg of molten bulk material is poured into the mold cavity, wherein the
molten bulk material is a manganese cast steel or a martensitic cast steel.
3. A method for casting a component according to claim 1, characterized in that a powder composition consisting of 70-80 wt.% reactant powder and 20-30 wt.% moderator
powder is inserted into a mold cavity with a wall thickness of at least 80 mm and
at least 250 kg of molten bulk material is poured into the mold cavity, wherein the
molten bulk material is a manganese cast steel or a martensitic cast steel.
4. A method for casting a component according to claim 1, characterized in that a powder composition consisting of 60-80 wt.% reactant powder and 20-40 wt.% moderator
powder is inserted into a mold cavity with a wall thickness of at least 85 mm and
at least 600 kg of molten bulk material is poured into the mold cavity, wherein the
molten bulk material is a cast iron, grey cast iron or a white chromium cast iron.
5. A method for casting a component according to claim 1, characterized in that a powder composition consisting of 55-70 wt.% reactant powder and 30-45 wt.% moderator
powder is inserted into a mold cavity with a wall thickness of at least 50 mm and
at least 800 kg of molten bulk material is poured into the mold cavity, wherein the
molten bulk material is a manganese cast steel or a martensitic cast steel.
6. A method for casting a component according to any of the above claims characterized in that the powder composition is inserted into the mold cavity as a layer and/or at least
one casting insert.
7. A method for casting a component according to any of the above claims characterized in that the powder composition is inserted into the mold cavity as at least two casting inserts,
which casting inserts are positioned with a separation distance of at least 5 mm,
preferably at least 8 mm.
8. A method for casting a component according to claim 7 characterized in that the powder composition is inserted into the mold cavity as at least five, preferably
at least nine casting inserts, wherein the separation distance between the fourth
and fifth, preferably the eighth and ninth, casting insert is increased to at least
10 mm, preferably at least 12 mm.
9. A method for casting a component according to any of the above claims, characterized in that the powder composition is inserted into the mold cavity and positioned to be in direct
contact with at least one wall of the mold cavity and/or at a distance to the wall
surfaces of the mold cavity.
10. Casted component for application in a high wear industrial environment with a composite
zone containing titanium carbides in a matrix material, the composite zone formed
in-situ during casting of molten bulk material and obtained by using a powder composition
comprising reactant powder, which forms the titanium carbides within the composite
zone and comprises titanium and carbon, and moderator powder, which forms the matrix
surrounding the titanium carbides within the composite zone and comprises metal powders,
characterized in that the bulk material of the casted component weighs at least 30 kg, preferably at least
100 kg and the casted component has a wall thickness of at least 40 mm.
11. Casted component according to claim 8, characterized in that the bulk material is a manganese cast steel, a martensitic cast steel, a cast iron,
a grey cast iron, or a white chromium cast iron.
12. Casted component according to claim 8, characterized in that the bulk material of the casted component weighs at least 100 kg, the casted component
has a wall thickness of at least 80 mm, and the bulk material is a manganese cast
steel or a martensitic cast steel.
13. Casted component according to claim 8, characterized in that the bulk material of the casted component weighs at least 250 kg, the casted component
has a wall thickness of at least 80 mm, and the bulk material is a manganese cast
steel or a martensitic cast steel.
14. Casted component according to claim 8, characterized in that the bulk material of the casted component weighs at least 600 kg, the casted component
has a wall thickness of at least 85 mm, and the bulk material is a cast iron, grey
cast iron or a white chromium cast iron.
15. Casted component according to claim 8, characterized in that the bulk material of the casted component weighs at least 800 kg, the casted component
has a wall thickness of at least 50 mm, and the bulk material is a manganese cast
steel or a martensitic steel.
16. Casted component according to any claims 8 to 13, characterized in that the casted component is a hammer, a blow bar, a roller, a cone, a mantle, a plate,
a screen liner, a pump chute or a duct.
17. A powder composition for casting a component for application in a high wear industrial
environment with a composite zone containing titanium carbides in a matrix material,
the composite zone formed in-situ during casting of molten bulk material and obtained
by using a powder composition comprising reactant powder, which forms the titanium
carbides within the composite zone and comprises titanium and carbon, and moderator
powder, which forms the matrix surrounding the titanium carbides within the composite
zone and comprises metal powders, characterized by a powder composition consisting of 55-80 wt.% reactant powder and 20-45 wt.% moderator
powder.
18. A powder composition according to claim 15, characterized in that the ratio of titanium to carbon in the reactant powder is 55 at. % to 45 at% or 45
at.% to 55 at.%, with a certainty of 2 %.
19. A powder composition according to claim 15 or 16, characterized in that the moderator powder consists of a mixture containing Fe, Mn, Si and C powder, preferably
also Cr powder.