BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a method of forming a composite component, in which
a plurality of feed materials are initially in a powdered state and a solid component
is formed by the application of heat.
[0002] The present invention also relates to an apparatus for forming a composite component,
of the type in which a plurality of feed materials are initially in a powdered state
and a solid component is formed by the application of heat.
2. Description of the Related Art
[0003] Composite components are component parts made from two or more dissimilar materials
that are consolidated to produce a single structure with characteristics different
from the individual constituent materials. The composite structure may be preferred
for a number of reasons for example in creating a multi-layer component having a hard
exterior surface but a low density, light-weight interior.
[0004] JPH 06 7916 (Kiyadeitsuku Technol Service K) shows an example casting method to create
this type of composite component in which a mixture of two powdered materials is added
into a mould cavity and utilises an induction coil so as to melt the powder mixture
so as to control the melting and solidifying and thus microstructure of the final
component.
[0005] A variety of methods are known for producing a multi-layer component comprising one
or more dissimilar materials, such as hard facing or laser cladding.
[0006] However these known methods incur a number of problems. Firstly, a disadvantage is
experienced in the number of separate processes required to create the finished component.
Secondly, such techniques of applying a layer of material to the exterior of a solid
object result in a non-discreet join of the two materials, leading to a structural
weakness at the interface.
[0007] US 2013/294901 A1 (Mironets et al) shows a method of component forming which includes positioning a metal powder into
a cavity before being melted in an induction furnace. This document also suggests
using component strengthening structures which are held in position by the component
once the component has been formed. A further method is shown in
EP 1 724 438 A2 (General Electric) in which a slip case is used in the casting method which separates
the two different powdered materials. The slip case is then removed to allow the powdered
materials to mix before solidification.
[0008] EP 0 072 175 A1 (Mowill) is an example of a hot isostatic process in which a basket is placed within an enclosure
to provide two separate regions for different powders or alloys. The basket allows
for diffusion of the two alloys as the alloys begin to melt. The basket may be removed
once the component is formed or melted and evaporated.
BRIEF SUMMARY OF THE INVENTION
[0009] According to a first aspect of the present invention, there is provided a method
of forming a composite component from a plurality of dissimilar powdered feed materials
comprising the steps of; obtaining a negative ceramic mould of a component defining
a first aperture associated with a first region of the mould and a second aperture
associated with a second region of the mould; deploying a first powdered feed material
into said first region of the negative mould via the first aperture and a second powdered
feed material into said second region of the negative mould via the second aperture;
preventing diffusion of said first feed material with said second feed material by
means of a partition separating said first region and said second region; increasing
the temperature within said negative mould to a first temperature causing said first
feed material to melt during a heating stage; and melting said partition to allow
diffusion of said first feed material with said second feed material.
[0010] According to a second aspect of the present invention there is provided an apparatus
for forming a composite component from a plurality of dissimilar powdered feed materials
comprising; a negative ceramic mould defining a first aperture associated with a first
region of the mould and a second aperture associated with a second region of the mould;
wherein said first aperture is configured for insertion of a first powdered feed material
into said first region of the mould and said second aperture is configured for insertion
of a second powdered feed material into a second region of the mould; and said negative
ceramic mould is suitable for heating to a first temperature during a heating stage,
characterised in that: said negative ceramic mould further comprises a partition separating
said first and said second regions, said partition configured to prevent diffusion
of said first feed material with said second feed material when in a solid form and
further configured to melt to allow diffusion of said first feed material with said
second feed material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
Figure 1 shows a method of forming a composite component from powdered feed materials;
Figure 2 shows a procedure for the creation of a negative mould;
Figure 3 shows the deployment of feed materials together in the mould of Figure 2;
Figure 4 shows a feeder section of a negative mould;
Figure 5 shows the negative mould of Figure 4 after solidification;
Figure 6 shows a mould with two regions and two feed materials being inserted separately;
Figure 7 shows the mould of Figure 6 after heating to join the feed materials;
Figure 8 shows a cross section view of a first mould with a partition;
Figure 9 shows in cross section a second mould with a partition;
Figure 10 shows a processing apparatus;
Figure 11 shows a temperature-time graph for the process of Figure 8;
Figure 12 shows a temperature-time graph for the process of Figure 9.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
Figure 1
[0012] A method of forming a composite component from powdered feed materials falling outside
the claimed invention is illustrated in Figure 1, in which a solid component is formed
from a plurality of dissimilar powdered feed materials by the application of heat.
[0013] At step
101, a negative mould
102 is obtained that defines the profile of a component to be produced. At step
103, the powdered feed materials, first feed material
104 and second feed material
105 are deployed into the negative mould. At step
106, heat is applied to the mould increasing the temperature and causing the powdered
feed materials to melt during a heating stage. At step
107 the temperature is maintained where necessary to allow diffusion of first feed material
104 with second feed material
105. At step
108 the temperature is decreased, causing the molten feed materials to solidify during
a cooling stage.
Figure 2
[0014] As discussed with reference to step
101 of the method of Figure 1, a negative mould is obtained from a positive model of
a component.
[0015] A method of obtaining a negative mould is illustrated in Figure 2. A positive model
201 is created from an appropriate medium such as a rapid prototyping material, polystyrene
or wax, defining the geometry of the desired component.
[0016] Negative mould
102 is then formed around the positive model to define a negative profile of the component.
In a first embodiment, the negative mould comprises a layer of material having a melting
point higher than that of first feed material
104 and second feed material
105, such as a very high temperature ceramic material. The ceramic shell is created by
applying a plurality of layers of ceramic slurry to the exterior of the positive model,
until the required wall thickness is achieved.
[0017] The sacrificial positive model material
201 is then evacuated from the negative mould
102 via aperture
202 using an appropriate removal technique, such as the application of heat and/or a
solvent. This leaves a cavity
203 defining the exterior surface of the component.
Figure 3
[0018] Step
103 of the method of Figure 1 for the deployment of feed materials is illustrated in
Figure 3. The positive sacrificial model
201 has been removed as shown previously with reference to Figure 2, leaving negative
mould
102 ready to receive feed material, such as first feed material
104 and second feed material
105 contained within feed device
301. In an embodiment the filling of negative mould
102 is facilitated by vibration of the mould to encourage the powdered feed materials
to settle. Negative mould
102 is placed upon vibrating table
302, itself supported by stable base member
303. In this way, as powdered feed materials are introduced to the mould they tend to
compact under gravity.
[0019] In the embodiment illustrated in Figure 3 first feed material
104 and second feed material
105 have been combined in powder form in feed device
301, prior to introduction to the mould. This type of powder preparation is advantageous
as it allows for very precise material compositions and uniform dispersions of particles
before agglomeration. First feed material
104 comprises a metallic melt powder with a first melting point and second feed material
105 comprises a ceramics substance with a much higher melting point than that of first
feed material
104.
[0020] Thus, in the illustrated embodiment first feed material
104 and second feed material
105 are deployed into the mould together via aperture
202 so as to fill cavity
203 within negative mould
102, and then heated as in step
106 during a heating stage. The temperature is increased by heating the negative mould
102 to a first temperature, approximately equal to the melting point of first feed material
104, thereby causing first feed material
104 to melt. However second feed material
105, having a melting point much higher than that of the first temperature is not melted
and remains in its solid particulate form.
[0021] In alternative embodiments the heating stage described above is performed in a pressure
controlled environment at a pressure other than atmospheric pressure of 1 bar. In
a first embodiment the pressure is reduced to below atmospheric pressure by removing
air from the pressure controlled environment. In a second embodiment the applied pressure
is increased to a level above atmospheric pressure. Equally the heating stage may
be performed under time-evolving pressure conditions.
Figure 4
[0022] A negative mould
401, substantially similar to negative mould
102, of Figure 3 is shown in partial cross section in Figure 4 after deploying step
103 and heating step
106. As previously described with reference to Figure 3, negative mould
401 has been heated to a first temperature thereby melting first feed material
104 whilst second feed material
105 is not melted but remains uniformly distributed throughout the casting. In this embodiment
mould
401 includes a component section
402 and a feeder section
403. The feeder section
403 defines a generally cylindrical passageway
404, extending from a first open end
405 and entering the component section
402 at a second end
406 via aperture
407.
[0023] Feeder section
403 feeds additional liquefied material into negative mould
401 during cooling stage
108 as the molten material contained within negative mould
401 contracts in volume. When materials cool from their molten liquid phase, their volume
reduces as the temperature decreases to the point at which they become solid. Therefore
feeders are used to provide liquefied material to compensate for the shrinkage cavities
that would otherwise form at one or more thermal centres in the interior of the casting.
Therefore the volume of the liquefied material in feeder section
403 is determined by the requirement for sufficient liquid material to be provided in
order to compensate for the volume reduction of the material as it cools. During solidification
the material contracts typically by about 7% by volume and consequently an equal volume
of liquefied material enters the component section from the feeder section.
[0024] The efficiency of the feeder section
403 is influenced by the static pressure in the feeder, resulting from the amount of
liquefied material it holds and its vertical height. The static pressure head assists
in forcing the liquefied material into the casting as it cools. Moulds in accordance
with this preferred embodiment have one or more feeders that are sufficiently tall
such that during production of the composite component, the height of liquefied material
within the feeder remains above the tallest part of the component section of the mould.
This allows sufficient pressure to be exerted on the molten material within the mould
as to ensure that any fine features defined by the mould are reproduced.
Figure 5
[0025] As previously discussed with reference to Figure 4, in an embodiment only first feed
material
104 is melted whilst second feed material
105 remains in its solid form. Figure 5 shows negative mould
401 after cooling stage
108 whereby the temperature within the mould has decreased to below the first temperature
causing said first feed material to solidify and the volume of liquefied material
within the feeder section has reduced to level
501. Therefore after cooling step
108, the molten first feed material
104 solidifies consolidating said second feed material particles
105 within the bulk casting providing structural locking. In this way composite components
may be produced that exhibit improved tensile and impact strengths, compared to those
components with a uniform composition.
[0026] Unlike negative mould apparatus of the prior art, in the illustrated embodiment negative
mould
401 is not hermetically sealed during heating stage
106 and cooling stage
108. Moulds of the prior art compensate for a reduction in volume of feed materials during
temperature changes by plastically deforming. In an embodiment negative mould
401 is substantially rigid and is configured to be incompressible so as not to deform
during heating stage
106 and cooling stage
108. In order to account for fluctuations in volume of the material within the negative
mould during temperature changes, negative mould
401 is configured to be pervious to the atmosphere during use. Therefore negative mould
401 exchanges volume with the atmosphere via aperture
407 and feeder section
403. However, in an alternative embodiment negative mould
401 is hermetically sealed after deploying stage
103 and prior to heating stage
106, by capping feeder section
403 to prevent interaction with the atmosphere.
[0027] In alternative embodiments the cooling stage may be conducted under pressure conditions
other than atmospheric pressure, or applied pressure may be varied as a function of
time. Altering the pressure under which the material solidifies can influence the
crystal structure of the casting. Solidifying during the cooling stage under increased
pressure conditions is likely to result in a denser and more structurally uniform
casting, enhancing the impact properties of the component.
Figure 6
[0028] The negative moulds
102 and
401 described with reference to Figures 1 to 5 have only a first aperture and corresponding
feeder section to allow deployment of feed materials into the mould. These embodiments
fall outside the present invention. However in an alternative embodiment in accordance
with the present invention, a mould is provided which has more than one aperture for
deployment of feed materials separately into different regions of the mould.
[0029] An example of such a mould is shown in cross section in Figure 6. The mould
601 has a first region
602 and a first aperture
603 associated with said first region
602, and a second aperture
604 associated with a second region
605. Similar to mould
102, mould
601 also includes feeder sections
606 and
607 extending from respective apertures.
[0030] First feed material
608 is deployed into first region
602, via first aperture
603 and feeder section
606. Second feed material
609 is deployed separately to said first feed material
608 into second region
605, via second aperture
604 and feeder section
607. This results in a casting with different materials localised to different regions
of the component. The feed materials are deployed into their respective regions at
roughly the same rate therefore they meet at an interface
610 that is approximately equidistant between first aperture
603 and second aperture
604.
Figure 7
[0031] Negative mould
601 previously discussed with reference to Figure 6 is shown in Figure 7 during the application
of heat. In this embodiment first feed material
608 and second feed material
609 are both metallic melt powders, therefore are melted when the temperature of mould
601 is increased to their respective melting points.
[0032] First feed material
608 is a metal powder with a melting temperature of 700°C and second feed material
609 is a different metal powder with a melting temperature of 1000°C.
[0033] Heat is applied to negative mould
601 as indicated by the arrows, so as to raise its temperature to a first temperature,
approximately equal to the melting point of the first feed material. Therefore first
feed material
608 is melted within first region
602. The temperature is further increased to a second temperature approximately equal
to the melting point of second feed material
609, thereby melting second feed material
609.
[0034] In an embodiment said first feed material
608 is joined to said second feed material
609 by selective alloying through solid state diffusion of the particles.
[0035] At this point both first feed material
608 and second feed material
609 are in their molten liquid states and thus diffusion occurs resultant of the Brownian
motion of the particles. At the interface
610 some of the particles of first feed material
608 deployed in first region
602 drift rightwards into second region
605. Similarly particles of second feed material
609 drift leftwards from second region
605 into first region
602, thereby alloying said first feed material
608 to said second feed material
609 across an alloyed region
701 about the interface
610.
[0036] The extent to which said first feed material
608 is alloyed to said second feed material
609 is controlled by the diameter
d of the alloyed region
701. The diameter
d of alloyed region
701 is dictated by the distance to which the particles are allowed to diffuse into the
adjacent region. This is dependent on the energy of the particles, itself a function
of the temperature, and the time period for which the feed materials are in their
molten state.
[0037] In the illustrated embodiment the second temperature is maintained during step
107, for a time period of 10 seconds, so as to allow diffusion of particles over an alloyed
region of diameter
d. When the desired degree of alloying is achieved the temperature of negative mould
601 is decreased to below the melting points of the feed materials thereby preventing
excessive diffusion of the molten materials.
[0038] Therefore once solidified a component is produced with a non-uniform metallurgy along
its length, with a discreet interface between the different regions of material. In
this way the component enjoys the functional benefits of both first feed material
608 and second feed material
609, whilst maintaining the structural properties of a single casting.
Figure 8
[0039] An example of a component produced by a process embodying the present invention is
illustrated in cross section in Figure 8. Figure 8 shows a negative mould
801, similar in construction to negative mould
601 of Figures 6 & 7, in that the moulding defines a component comprising a first region
802 and a second region
803, accessed by apertures
804 and
805 respectively. First region
802 is filled with first feed material
806 which is a titanium powder and second region
803 is filled with second feed material
807 which is a titanium carbide powder.
[0040] Additionally negative mould
801 comprises a partition
808 thereby dividing first region
802 and second region
803. Partition
808 is a titanium sheath that is approximately 2mm in thickness and completely separates
first region
802 from second region
803.
[0041] When producing more complex components using powder pressing techniques a problem
is experienced in terms of maintaining the positioning of the feed materials, to prevent
gravitational sedimentation or incidental dispersion in the powder phase prior to
melting. By including partition
808 first feed material
806 in first region
802 is prevented from migrating into second region
803 and diffusing with second feed material
807 until partition
808 is melted.
[0042] In this embodiment the object to be produced is a rack component corresponding to
a rack and pinion arrangement, used for transforming the rotational motion of a toothed
pinion gear into linear motion of the splined rack. The splined surface of the rack
component is repeatedly subjected to a torque exerted by the pinion gear; therefore
must be extremely hard so as to be resistant to material degradation. However, additionally
the component must be relatively lightweight.
[0043] Thus, it is desirable to have a first region of the component composed of a substance
that is sufficiently lightweight, such as titanium, but wherein the driving splines
have an increased surface hardness for example by using a titanium carbide powder.
[0044] In the illustrated embodiment first feed material
806 second feed material
807 and partition
808 each have a melting point corresponding to a first temperature. Therefore upon application
of heat to a first temperature, as in step
106 and described with reference to figure 7, first feed material
806, second feed material
807 and partition
808 are melted, thereby allowing interaction of the molten feed materials in the opposing
regions.
[0045] As in step
107 the temperature is maintained for a period of time to allow a diffusion layer of
sufficient diameter as to create a discreet interface between first feed material
806 and second feed material
807 to form.
[0046] When the diffusion layer forming the alloyed region is the desired diameter the temperature
is decreased to below said first temperature, causing the casting to solidify during
a cooling stage.
[0047] Although cooling at a natural rate may be suitable for some materials, others may
require accelerated cooling. In an embodiment the temperature of the mould is decreased
rapidly by forcing an inert gas such as argon or helium to flow over the negative
mould
801.
Figure 9
[0048] A fifth example of a mould embodying the present invention is shown in Figure 9.
Mould
901 for producing a gas turbine blade component is illustrated comprising a first region
902 innermost, contained within partition
903 and a second region
904 outermost.
[0049] Similarly to Figure 8, first region
902 is fed via first feeder section
905 through first aperture
906, and second region
904 is fed through second feeder section
907 and second aperture
908.
[0050] In an embodiment of the invention partition
903 is invested within the positive wax model of the component, as shown with reference
to Figure 2 during construction of mould
901. Therefore when the sacrificial material forming the positive model is removed partition
903 remains inside negative mould
901 supported by feeder section
905.
[0051] In the illustrated embodiment first feed material
909 in first region
902 and second feed material
910 in second region
904 are metallic powders. First feed material
909 is a low density metal powder such as aluminium with superior thermal conductivity
characteristics, whilst second feed material
910 is a high density metal such as steel with increased surface hardness. First feed
material
909 and second feed material
910 both have a melting point corresponding to a first temperature.
[0052] Partition
903 comprises a third material such as nickel which is beneficial to the alloying process,
and having a melting point corresponding to a second temperature, higher than the
first temperature.
[0053] Therefore when the temperature of mould
901 is increased to the first temperature, both first feed material
909 and second feed material
910 are melted, however they are separated by partition
903 which remains in solid form. Further increasing the temperature of the negative mould
901 to the second temperature causes the partition
903 to be melted, thereby allowing diffusion of first feed material
909 with second feed material
910, creating an alloyed region comprising both first feed material aluminium particles,
second feed material steel particles and partition material nickel particles.
[0054] By altering the composition of the material used to create partition
903 it is possible to influence the melting point and therefore alloying temperature
of the various feed materials.
[0055] In an embodiment the partition
903 is formed of a ceramic material having a melting point far greater than the melting
points of the feed materials. Therefore the alloying process is conducted at a greatly
increased temperature, resulting in a more uniform crystalline structure of the alloyed
region.
[0056] Although the invention has been described by embodiments present using only two powdered
feed materials, it will be appreciated that in alternative embodiments any number
of dissimilar feed powders may be used.
[0057] Equally components may be created with any number of different localised regions
of dissimilar materials, accessed by any number of apertures for insertion of feed
materials. Indeed in a yet further alternative embodiment of the present invention
a multi-core rod component is formed, comprising ten regions separated by nine partitions
into which ten dissimilar feed materials are deployed.
Figure 10
[0058] Apparatus for performing the processing method embodying the present invention in
which moulds such as negative mould
901, containing powdered feed materials are processed to form a composite component, is
illustrated in Figure
10.
[0059] The apparatus
1001 comprises a vacuum furnace
1002, creating a vacuum-tight chamber
1003 and having a door
1004 to allow loading and unloading of the chamber
1003.
[0060] In an embodiment vacuum furnace
1002 includes means for varying the temperature and pressure within. Vacuum furnace
1002 has a heat source for producing radiant heat such as resistance heating element
1005, which is connected to power supply
1006.
[0061] The apparatus
1001 also includes a vacuum pump
1007 connected to chamber
1003 for evacuating air from the chamber
1003 such that the pressure in the chamber may be reduced to below atmospheric pressure.
Additionally a compressor
1008 is also provided so as to allow the pressure inside the chamber
1003 to be increased above atmospheric pressure.
[0062] Electronic controller
1009 is provided comprising temperature sensor
1010 and pressure sensor
1011 and associated wiring. Temperature sensor
1010 is located within chamber
1003 and is configured to provide signals indicative of the actual temperature within
chamber
1003. Similarly pressure sensor
1011 is configured to provide an indication of the air pressure within the chamber
1003.
[0063] Electronic controller
1009 is configured to receive signals from temperature sensor
1010 and pressure sensor
1011, and modulate the power supply
1006 for the resistance heating element
1005, vacuum pump
1007 and compressor
1008 accordingly. In an embodiment, controller
1009 is a programmed computer system or microcontroller.
[0064] In an embodiment of the invention it is desirable that the cooling stage is accelerated
to cause the molten feed materials to decrease in temperature and solidify more rapidly.
Therefore compressor
1008 is used to force an inert gas, such as nitrogen into vacuum chamber
1003 whilst vacuum
1007 evacuates the spent gas, thereby creating a cooling convection current over negative
mould
901.
Figure 11
[0065] An example of process steps
106-108 embodying an aspect of the present invention as illustrated in Figure 8 is depicted
by the graph of Figure 11. The graph
1101 shows a plot of temperature (T) as a function of time (t).
[0066] Initially at time
1102 the chamber of vacuum furnace
1002 is at ambient temperature
1103. Electrical power is then supplied to the resistance heating coils, at time
1104 until time
1105 to raise the temperature within the chamber to a first temperature
1106, above the melting point of first feed material
806, second feed material
807 and partition
808, thereby establishing molten liquid within mould
801.
[0067] The increased temperature
1106 is stably maintained between times
1105 and
1107, thereby maintaining the feed materials in their molten state and enabling a degree
of diffusion at the interface.
[0068] When the period of time that has elapsed is sufficiently long to allow a suitable
amount of diffusion between first feed material
806 and second feed material
807, creating an alloyed region of desired diameter, power to the resistance coils is
interrupted and heating stops.
[0069] At time
1107 the power is cut-off and the chamber is allowed to cool naturally, until at time
1108 the temperature has returned to ambient temperature
1103, the casting has solidified and may now be removed from the chamber.
Figure 12
[0070] A second example of process steps
106-108 embodying the aspect of the invention as illustrated in Figure 9, is shown by graph
1201 in Figure 12.
[0071] Again at time
1102 the vacuum furnace chamber is at ambient temperature
1103. At time
1104 the heating stage begins and the temperature of the chamber increases until the first
temperature
1106 at time
1105. At this stage first feed material
909 and second feed material
910, both having melting temperatures below first temperature
1106, have been melted and are in their molten state.
[0072] However as discussed with reference to Figure 9, partition
903 has a higher melting point than either first feed material
909 or second feed material
910, therefore remains in its solid phase. Therefore in this embodiment heating continues
for a further period of time, until time
1202 when the temperature has increased to second temperature
1203 and the partition is melted. At this stage both first feed material
909, second feed material
910 and partition
903 are in molten states and begin to diffuse at the interface. In this embodiment it
is desirable that the alloyed region created by the diffusion of particles is relatively
larger in diameter than the alloyed region created in the process shown in Figure
11. Therefore the increased temperature is maintained for a longer period of time,
from time
1202 until time
1203, thereby allowing a greater degree of particle diffusion. At time
1203 the alloyed region is of adequate diameter and therefore power to the heating coil
is interrupted and cooling begins.
[0073] In this embodiment it is desirable that the cooling stage is accelerated. Therefore
at time
1203 compressor
1008 and vacuum
1007 are configured to force a convection current over the negative mould
901, as described with reference to Figure 10 during the cooling step of
108. This results in a rapid decrease in temperature of negative mould
901 and consequently solidification of the molten feed materials occurs quickly. At time
1204 the temperature in the chamber has returned to ambient temperature
1003 and the mould may be removed from the chamber and further processed if necessary.
1. A method of forming a composite component from a plurality of dissimilar powdered
feed materials, comprising the steps of:
obtaining a negative ceramic mould (102, 401, 601, 801, 901) of a component defining
a first aperture (603, 804, 906) associated with a first region (602, 802, 902) of
the mould and a second aperture (604, 805, 908) associated with a second region (605,
803, 904) of the mould;
deploying a first powdered feed material (104, 608, 806, 909) into said first region
of the negative mould via the first aperture and a second powdered feed material (105,
609, 807, 910) into said second region of the negative mould via the second aperture;
preventing diffusion of said first feed material with said second feed material by
means of a partition (808, 903) separating said first region and said second region;
increasing the temperature within said negative mould to a first temperature (1106)
causing said first feed material to melt during a heating stage (106); and
melting said partition to allow diffusion of said first feed material with said second
feed material.
2. The method of claim 1, wherein said partition is melted when the temperature of said
negative mould is increased to said first temperature during said heating stage.
3. The method of claim 1 or claim 2, wherein said second feed material is melted during
said heating stage.
4. The method of any of claims 1 to 3, wherein said first powdered feed material diffuses
with said second powdered feed material during said heating stage to join said first
and second powdered feed materials.
5. The method of any of claims 1 to 4, wherein said first feed material and said second
feed material are metals.
6. The method of claim 5, wherein said first feed metal is joined to said second feed
metal by diffusion of the particles during said heating stage to alloy said first
and second metals over an alloyed region (701) at the interface (610).
7. The method of any of claims 1 to 6, further comprising the step of:
decreasing the temperature within said negative mould to below said first temperature
causing said first feed material to solidify during a cooling stage (108).
8. The method of claim 7, further comprising the step of:
feeding additional liquefied material into said negative mould during said cooling
stage as the material contained within said negative mould contracts in volume.
9. The method of any of claims 1 to 8, wherein said heating stage is performed under
a pressure other than atmospheric pressure.
10. The method of any of claims 7 to 9, wherein said cooling stage is performed under
a pressure other than atmospheric pressure.
11. The method of any of claims 1 to 10, wherein the temperature within said mould is
increased to a second temperature (1203) during said heating stage.
12. The method of claim 11, wherein said partition is melted when the temperature of said
negative mould is increased to said second temperature during said heating stage.
13. An apparatus for forming a composite component from a plurality of dissimilar powdered
feed materials, comprising:
a negative ceramic mould (102, 401, 601, 801, 901) defining a first aperture (603,
804, 906) associated with a first region (602, 802, 902) of the mould and a second
aperture (604, 805, 908) associated with a second region (605, 803, 904) of the mould;
wherein;
said first aperture is configured for insertion of a first powdered feed material
(104, 608, 806, 909) into said first region of the mould and said second aperture
is configured for insertion of a second powdered feed material (105, 609, 807, 910)
into a second region of the mould; and
said negative ceramic mould is suitable for heating to a first temperature (1106)
during a heating stage(106), characterised in that: said negative ceramic mould further comprises a partition (808, 903) separating
said first and said second regions, said partition configured to prevent diffusion
of said first feed material with said second feed material when in a solid form and
further configured to melt to allow diffusion of said first feed material with said
second feed material.
14. The apparatus of claim 13, wherein said negative ceramic mould is configured to be
pervious to the atmosphere in use.
1. Ein Verfahren zum Herstellen einer Verbundkomponente aus einer Vielzahl unterschiedlicher
Einsatzmaterialien in Pulverform, bestehend aus folgenden Schritten:
Herstellen einer Negativform aus Keramik (102, 401, 601, 801, 901) für eine Komponente,
wobei eine erste Öffnung (603, 804, 906) als Zugang für eine erste Region (602, 802,
902) der Form sowie eine zweite Öffnung (604, 805, 908) als Zugang für eine zweite
Region (605, 803, 904) der Form dient;
Einfüllen des ersten Einsatzmaterials in Pulverform (104, 608, 806, 909) in diese
erste Region der Negativform über die erste Öffnung und eines zweiten Einsatzmaterials
in Pulverform (105, 609, 807, 910) in die genannte zweite Region der Negativform über
die zweite Öffnung;
Verhindern des Eindringens des genannten ersten Einsatzmaterials in das zweite Einsatzmaterial
mithilfe einer Trennvorrichtung (808, 903), die die oben beschriebene erste und zweite
Region voneinander trennt;
Erhöhen der Temperatur in dieser Negativform auf eine erste Temperatur (1106), durch
die das erste Einsatzmaterial während eines Erwärmungsvorgangs (106) schmilzt; und
Schmelzen der genannten Trennvorrichtung, sodass das oben genannte erste Einsatzmaterial
in das oben beschriebene zweite Einsatzmaterial eindringen kann.
2. Das Verfahren nach Patentanspruch 1, wobei die Trennvorrichtung schmilzt, sobald die
Temperatur der Negativform auf die oben beschriebene erste Temperatur des Erwärmungsvorgangs
ansteigt.
3. Das Verfahren nach Patentanspruch 1 oder 2, wobei das zweite Einsatzmaterial während
des Erwärmungsvorgangs schmilzt.
4. Das Verfahren nach den Patentansprüchen 1 bis 3, wobei das genannte erste Einsatzmaterial
in Pulverform während der beschriebenen Erwärmungsphase in das zweite Einsatzmaterial
in Pulverform eindringt, sodass sich erstes und zweites Einsatzmaterial in Pulverform
vermengen.
5. Das Verfahren nach den Patentansprüchen 1 bis 4, wobei es sich beim beschriebenen
ersten Einsatzmaterial und dem beschriebenen zweiten Einsatzmaterial um Metalle handelt.
6. Das Verfahren nach Patentanspruch 5, wobei das genannte erste Einsatzmetall mit dem
genannten zweiten Einsatzmetall durch Eindringung während des Erwärmungsvorgangs vermengt
wird, sodass eine Legierung des ersten und zweiten Metalls in einer Legierungsregion
(701) an der Kontaktstelle beider Materialien (610) entsteht.
7. Das Verfahren nach den Patentansprüchen 1 bis 6, die um den folgenden Schritt ergänzt
wurden:
Senken der Temperatur in der genannten Negativform auf eine Temperatur unterhalb der
genannten ersten Temperatur, sodass sich das genannte erste Einsatzmaterial während
eine Kühlphase (108) verfestigt.
8. Das Verfahren nach Patentanspruch 7, das um den folgenden Schritt ergänzt wurde:
Zuführen weiteren verflüssigten Materials in die genannte Negativform während der
beschriebenen Kühlphase, während der sich das Material in der genannten Negativform
zusammenzieht.
9. Das Verfahren nach den Patentansprüchen 1 bis 8, wobei die Erwärmungsphase unter einem
Druck durchgeführt wird, der nicht dem üblichen Atmosphärendruck entspricht.
10. Das Verfahren nach den Patentansprüchen 7 bis 9, wobei die genannte Kühlphase unter
einem Druck durchgeführt wird, der nicht dem üblichen Atmosphärendruck entspricht.
11. Das Verfahren nach den Patentansprüchen 1 bis 10, wobei die Temperatur in der genannten
Form während der genannten Erwärmungsphase auf eine zweite Temperatur (1203) erhöht
wird.
12. Das Verfahren nach Patentanspruch 11, wobei die genannte Trennvorrichtung schmilzt,
wenn die Temperatur der genannten Negativform während der Erwärmungsphase auf die
genannte zweite Temperatur erhöht wird.
13. Eine Vorrichtung zum Herstellen einer Verbundstoffkomponente aus einer Vielzahl unterschiedlicher
Einsatzmaterialien in Pulverform, bestehend aus:
einer Negativform aus Keramik (102, 401, 601, 801, 901) mit einer ersten Öffnung (603,
804, 906) für eine erste Region (602, 802, 902) der Form sowie einer zweiten Öffnung
(604, 805, 908) für eine zweite Region (605, 803, 904) der Form, wobei
die genannte erste Öffnung zum Einführen eines ersten Einsatzmaterials in Pulverform
(104, 608, 806, 909) in diese erste Region der Form und die genannte zweite Öffnung
zum Einführen eines zweiten Einsatzmaterials in Pulverform (105, 609, 807, 910) in
die genannte zweite Region der Form vorgesehen ist; und
sich die genannte Negativform aus Keramik zum Erwärmen auf eine erste Temperatur (1106)
während eines Erwärmungsvorgangs (106) eignet, gekennzeichnet durch:
eine Trennvorrichtung (808, 903) der genannten Negativform aus Keramik zwischen der
genannten ersten und zweiten Region, wobei diese Trennvorrichtung ein Eindringen des
genannten ersten Einsatzmaterials in das genannte zweite Einsatzmaterial verhindern
soll, wenn diese in fester Form vorliegen, und schmilzt, um ein Eindringen des genannten
ersten Einsatzmaterials in das genannte zweite Einsatzmaterial zu ermöglichen.
14. Die Vorrichtung aus Patentanspruch 13, wobei die Atmosphäre in die genannte Negativform
aus Keramik eindringen kann.
1. Une méthode de formation d'un composant composite à partir de plusieurs matières d'alimentation
en poudre différentes, comprenant les étapes :
d'obtention d'un moule en céramique négatif (102, 401, 601, 801, 901) d'un composant
définissant une première ouverture (603, 804, 906) associée à une première zone (602,
802, 902) du moule et une deuxième ouverture (604, 805, 908) associée à une deuxième
zone (605, 803, 904) du moule ;
de déploiement d'une première matière d'alimentation en poudre (104, 608, 806, 909)
dans ladite première zone du moule négatif via la première ouverture et une deuxième
matière d'alimentation en poudre (105, 609, 807, 910) dans ladite deuxième zone du
moule négatif via la deuxième ouverture ;
de prévention de la dispersion de ladite première matière d'alimentation dans ladite
deuxième matière d'alimentation en grâce à une partition (808, 903) séparant ladite
première zone et ladite deuxième zone ;
d'augmentation de la température dans ledit moule négatif à une première température
(1106) entraînant la fonte de ladite première matière d'alimentation lors d'une phase
de chauffe (106) ; et
de fonte de ladite partition pour permettre la dispersion de ladite première matière
d'alimentation dans ladite deuxième matière d'alimentation.
2. La méthode selon la revendication 1, ladite partition fondant lorsque la température
dudit moule négatif est augmentée pour atteindre ladite première température durant
ladite phase de chauffe.
3. La méthode selon la revendication 1 ou 2, ladite deuxième matière d'alimentation fondant
pendant ladite phase de chauffe.
4. La méthode selon une quelconque des revendications 1 à 3, ladite première matière
d'alimentation en poudre se dispersant dans ladite deuxième matière d'alimentation
en poudre durant ladite phase de chauffe pour relier lesdites première et deuxième
matières d'alimentation en poudre.
5. La méthode selon une quelconque des revendications 1 à 4, ladite première matière
d'alimentation et ladite deuxième matière d'alimentation étant des métaux.
6. La méthode selon la revendication 5, ladite première alimentation métallique étant
reliée à ladite deuxième alimentation métallique par la dispersion des particules
durant ladite phase de chauffe pour allier lesdits premier et deuxième métaux sur
une zone en alliage (701) à l'interface (610).
7. La méthode selon une quelconque des revendications 1 à 6, comprenant également l'étape
de :
diminution de la température dans ledit moule négatif à une température inférieure
à ladite première température, entraînant la solidification de ladite première matière
d'alimentation pendant une phase de refroidissement (108).
8. La méthode selon la revendication 7, comprenant également l'étape de :
ajout des matières liquéfiées supplémentaires dans ledit moule négatif pendant ladite
phase de refroidissement alors que le volume de la matière contenue dans ledit moule
négatif se contracte.
9. La méthode selon une quelconque des revendications 1 à 8, ladite phase de chauffe
se déroulant sous une pression non atmosphérique.
10. La méthode selon une quelconque des revendications 7 à 9, ladite phase de refroidissement
se déroulant sous une pression non atmosphérique.
11. La méthode selon une quelconque des revendications 1 à 10, la température dans ledit
moule étant augmentée à une deuxième température (1203) pendant ladite phase de chauffe.
12. La méthode selon la revendication 11, ladite partition ayant fondu lors de l'augmentation
de la température dudit moule négatif à ladite deuxième température durant la phase
de chauffe.
13. Un appareil pour former un composant en composite à partir de plusieurs matières d'alimentation
en poudre différentes, comprenant :
un moule négatif en céramique (102, 401, 601, 801, 901) définissant une première ouverture
(603, 804, 906) associée à une première zone (602, 802, 902) du moule et une deuxième
ouverture (604, 805, 908) associée à une deuxième zone (605, 803, 904) du moule ;
lorsque :
ladite première ouverture est configurée pour l'insertion d'une première matière d'alimentation
en poudre (104, 608, 806, 909) dans ladite première zone du moule et ladite deuxième
ouverture est configurée pour l'insertion d'une deuxième matière d'alimentation en
poudre (105, 609, 807, 910) dans une deuxième zone du moule ; et
ledit moule négatif en céramique est conçu pour être chauffé à une première température
(1106) pendant une phase de chauffe (106), caractérisé en ce que :
ledit moule négatif en céramique comprend également une partition (808, 903) séparant
lesdites première et deuxième zones, ladite partition étant configurée pour prévenir
la dispersion de ladite première matière d'alimentation dans ladite deuxième matière
d'alimentation lorsqu'elle est sous forme solide et également configurée pour fondre
et permettre la dispersion de ladite première matière d'alimentation dans ladite deuxième
matière d'alimentation.
14. L'appareil selon la revendication 13, ledit moule négatif en céramique étant configuré
pour être perméable à l'atmosphère utilisée.