|
(11) | EP 3 896 183 A1 |
(12) | EUROPEAN PATENT APPLICATION |
published in accordance with Art. 153(4) EPC |
|
|
|
|
|||||||||||||||||||||||||||
(54) | LIGHTWEIGHT HIGH-ENTROPY ALLOY HAVING HIGH STRENGTH AND HIGH PLASTICITY AND PREPARATION METHOD THEREFOR |
(57) The invention relates to a lightweight high-entropy alloy with high strength and
high plasticity and a preparation method thereof, belonging to the fields of metal
materials and preparation thereof. The high-entropy alloy is mainly composed of Ti,
Zr, V, Nb and M, wherein M is one or more of Al, Hf, Cr, Fe, Mg, Be, Li, Mo, Co, Ni,
Si, B, O and N. By regulating contents of all the elements, the high-entropy alloy
has low density, high strength and high plasticity so as to have a huge application
potential in the field of engineering. Moreover, the preparation method of the high-entropy
alloy is easy to operate as well as safe and reliable, the adopted raw materials are
nontoxic and harmless, and the high-entropy alloy is economical and practical. |
TECHNICAL FIELD
BACKGROUND
SUMMARY
step 1, placing clean elemental raw materials Ti, Zr, V, Nb and M into a smelting furnace of which the vacuum degree is smaller than or equal to 2.5×10-3 Pa, and filling the smelting furnace with a protective gas; then, performing smelting, and cooling an alloy liquid generated by smelting to obtain an alloy ingot; and overturning the alloy ingot, and performing repeated smelting for more than three times to ensure that components are uniform to obtain a high-entropy alloy ingot; and
step 2, sealing the high-entropy alloy ingot in an argon-filled quartz tube, performing solution treatment at the temperature of 900-1200°C, and keeping the temperature for 1-12 h to obtain the high-entropy alloy.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a comparison diagram of X-ray diffractometer (XRD) spectrums of high-entropy alloys prepared in Embodiments 1-6;
Fig. 2 is a metallographic diagram of a high-entropy alloy Ti60Zr20V3Nb17 prepared in Embodiment 1;
Fig. 3 is a metallographic diagram of a high-entropy alloy Ti30Zr27V18Nb25 prepared in Embodiment 2;
Fig. 4 is a metallographic diagram of a high-entropy alloy Ti50Zr18V12Nb16Al4 prepared in Embodiment 3;
Fig. 5 is a metallographic diagram of a high-entropy alloy Ti40Zr23V13Nb19Al5 prepared in Embodiment 4;
Fig. 6 is a metallographic diagram of a high-entropy alloy Ti30Zr45Nb7Al8Hf10 prepared in Embodiment 5;
Fig. 7 is a metallographic diagram of a high-entropy alloy Ti50Zr25V7Nb12Al5Fe1 prepared in Embodiment 6; and
Fig. 8 is a comparison diagram of quasi-static tensile engineering stress-strain curves of the high-entropy alloys prepared in Embodiments 1-6.
DETAILED DESCRIPTION
high-vacuum non-consumable electric arc smelting furnace: DHL-400 high-vacuum non-consumable electric arc smelting furnace produced by SKY Technology Development Co., Ltd, CAS (Chinese Academy of Sciences);
phase analysis: an X-ray diffractometer (XRD) spectrum of the prepared high-entropy alloy is measured by adopting a Rigaku Smartlab X-ray Diffractometer, wherein a Kα ray on a Cu target is adopted, a working voltage is 40 kV, a working current is 110 mA, a scanning angle ranges from 20° to 90°, a scanning speed is 5°/min, a step length is 0.02°, and a measured angle error is smaller than 0.01°; and the size of a specimen measured by the XRD is 10 mm×10 mm×5 mm; and firstly, six surfaces are ground to be flat with 240# abrasive paper, and then, an irradiated surface is sequentially ground with 400# abrasive paper, 600# abrasive paper, 800# abrasive paper, 1000# abrasive paper, 1200# abrasive paper, 1500# abrasive paper, and 2000# abrasive paper;
microstructure: a microstructure of the prepared high-entropy alloy in a solution state is observed by adopting an Axio observer Aim research-grade metalloscope produced by the Deiss company in Germany, wherein the size of a metallographic specimen is 10 mm×10 mm×5 mm; and the metallographic specimen is firstly mounted by using a hot mounting press, then, is polished sequentially with 400# abrasive paper, 600# abrasive paper, 800# abrasive paper, 1000# abrasive paper, 1200# abrasive paper, 1500# abrasive paper, 2000# abrasive paper, 3000# abrasive paper, 5000# abrasive paper, and 7000# abrasive paper, and then, is polished with a silicon dioxide suspension with the particle size of 0.02 µm, and is finally soaked in a corrosive agent containing HF, HNO3 and H2O in a volume ratio of 1:3:20 for 5-30 s;
density measurement: the density of the prepared high-entropy alloy is measured by adopting a hydrostatic weighing method according to the standard GB/T1423-1996; firstly, the specimen is placed in the air to be weighed, then, the specimen is placed on a lifting appliance to be weighed in water, finally, the lifting appliance is placed in water alone to be weighed, a buoyancy of the specimen in water is obtained by calculation according to the three weighed values, the volume of the specimen is
calculated in combination with the water density, and the density of the alloy may be calculated according to the mass of the specimen in the air and the calculated volume, wherein the used specimen is the same as the specimen measured by XRD; and quasi-static tensile mechanical property test: an axial quasi-static tensile test at room temperature is performed by adopting a CMT4305 microcomputer electronic universal testing machine according to the standard GB/T228.1-2010, a strain rate is selected as 10-3s-1, and a test specimen is a non-standard I-shaped piece with the thickness of 1.0 mm, the width of 3.14 mm, the parallel segment length of 10 mm and the gauge length of 5 mm.
Embodiment 1
step 1, elements Ti, Zr, V and Nb of which the purities are not smaller than 99.7wt% are adopted as raw materials, the raw materials are firstly polished by using a grinding wheel to remove oxide coatings on surfaces of the raw materials, and are then cleaned with anhydrous ethanol by ultrasonic oscillation, and clean raw materials with a total mass of (70±0.01) g are weighed according to an atomic percentage of Ti:Zr:V:Nb=60:20:3:17;
step 2, the weighed raw materials are sequentially placed in a water-cooled copper crucible of a high-vacuum non-consumable electric arc smelting furnace according to melting points from low to high, then, vacuumization is performed, and after the vacuum degree in the smelting furnace reaches 2.5×10-3 Pa, and argon is filled as a protective gas; before the alloy is smelted, firstly, a pure metal titanium ingot is smelted to further reduce the content of oxygen in a furnace chamber of the smelting furnace, then, alloying smelting is performed, electromagnetic stirring is utilized for alloy homogenization during smelting, and an alloy liquid generated by smelting is cooled to obtain an alloy ingot; and the alloy ingot is overturned and is repeatedly smelted for four times to obtain a high-entropy alloy ingot; and step 3, the high-entropy alloy ingot is sealed in an argon-filled quartz tube to be subjected to solution treatment at the temperature of 900°C, and the temperature is kept for 1 h to obtain the high-entropy alloy Ti60Zr20V3Nb17.
Embodiment 2
step 1, elements Ti, Zr, V and Nb of which the purities are not smaller than 99.7wt% are adopted as raw materials, the raw materials are firstly polished by using a grinding wheel to remove oxide coatings on surfaces of the raw materials, and are then cleaned with anhydrous ethanol by ultrasonic oscillation, and clean raw materials with a total mass of (70±0.01) g are weighed according to an atomic percentage of Ti:Zr:V:Nb=30:27: 18:25;
step 2, the weighed raw materials are sequentially placed in a water-cooled copper crucible of a high-vacuum non-consumable electric arc smelting furnace according to melting points from low to high, then, vacuumization is performed, and after the vacuum degree in the smelting furnace reaches 2.5×10-3 Pa, and argon is filled as a protective gas; before the alloy is smelted, firstly, a pure metal titanium ingot is smelted to further reduce the content of oxygen in a furnace chamber of the smelting furnace, then, alloying smelting is performed, electromagnetic stirring is utilized for alloy homogenization during smelting, and an alloy liquid generated by smelting is cooled to obtain an alloy ingot; and the alloy ingot is overturned and is repeatedly smelted for four times to obtain a high-entropy alloy ingot; and
step 3, the high-entropy alloy ingot is sealed in an argon-filled quartz tube to be subjected to solution treatment at the temperature of 1200°C, and the temperature is kept for 1 h to obtain the high-entropy alloy Ti30Zr27V18Nb25.
Embodiment 3
step 1, elements Ti, Zr, V, Nb and Al of which the purities are not smaller than 99.7wt% are adopted as raw materials, the raw materials are firstly polished by using a grinding wheel to remove oxide coatings on surfaces of the raw materials, and are then cleaned with anhydrous ethanol by ultrasonic oscillation, and clean raw materials with a total mass of (70±0.01) g are weighed according to an atomic percentage of Ti:Zr:V:Nb:Al=50:18:12:16:4;
step 2, the weighed raw materials are sequentially placed in a water-cooled copper crucible of a high-vacuum non-consumable electric arc smelting furnace according to melting points from low to high, then, vacuumization is performed, and after the vacuum degree in the smelting furnace reaches 2.5×10-3 Pa, and argon is filled as a protective gas; before the alloy is smelted, firstly, a pure metal titanium ingot is smelted to further reduce the content of oxygen in a furnace chamber of the smelting furnace, then, alloying smelting is performed, electromagnetic stirring is utilized for alloy homogenization during smelting, and an alloy liquid generated by smelting is cooled to obtain an alloy ingot; and the alloy ingot is overturned and is repeatedly smelted for four times to obtain a high-entropy alloy ingot; and
step 3, the high-entropy alloy ingot is sealed in an argon-filled quartz tube to be subjected to solution treatment at the temperature of 1000°C, and the temperature is kept for 3 h to obtain the high-entropy alloy Ti50Zr18V12Nb16Al4.
Embodiment 4
step 1, elements Ti, Zr, V, Nb and Al of which the purities are not smaller than 99.7wt% are adopted as raw materials, the raw materials are firstly polished by using a grinding wheel to remove oxide coatings on surfaces of the raw materials, and are then cleaned with anhydrous ethanol by ultrasonic oscillation, and clean raw materials with a total mass of (70±0.01) g are weighed according to an atomic percentage of Ti:Zr:V:Nb:Al=40:23:13:19:5;
step 2, the weighed raw materials are sequentially placed in a water-cooled copper crucible of a high-vacuum non-consumable electric arc smelting furnace according to melting points from low to high, then, vacuumization is performed, and after the vacuum degree in the smelting furnace reaches 2.5×10-3 Pa, and argon is filled as a protective gas; before the alloy is smelted, firstly, a pure metal titanium ingot is smelted to further reduce the content of oxygen in a furnace chamber of the smelting furnace, then, alloying smelting is performed, electromagnetic stirring is utilized for alloy homogenization during smelting, and an alloy liquid generated by smelting is cooled to obtain an alloy ingot; and the alloy ingot is overturned and is repeatedly smelted for four times to obtain a high-entropy alloy ingot; and
step 3, the high-entropy alloy ingot is sealed in an argon-filled quartz tube to be subjected to solution treatment at the temperature of 1100°C, and the temperature is kept for 3 h to obtain the high-entropy alloy Ti40Zr23V13Nb19Al5.
Embodiment 5
step 1, elements Ti, Zr, Nb, Al and Hf of which the purities are not smaller than 99.7wt% are adopted as raw materials, the raw materials are firstly polished by using a grinding wheel to remove oxide coatings on surfaces of the raw materials, and are then cleaned with anhydrous ethanol by ultrasonic oscillation, and clean raw materials with a total mass of (70±0.01) g are weighed according to an atomic percentage of Ti:Zr:Nb:Al:Hf=30:45:7:8:10;
step 2, the weighed raw materials are sequentially placed in a water-cooled copper crucible of a high-vacuum non-consumable electric arc smelting furnace according to melting points from low to high, then, vacuumization is performed, and after the vacuum degree in the smelting furnace reaches 2.5×10-3 Pa, and argon is filled as a protective gas; before the alloy is smelted, firstly, a pure metal titanium ingot is smelted to further reduce the content of oxygen in a furnace chamber of the smelting furnace, then, alloying smelting is performed, electromagnetic stirring is utilized for alloy homogenization during smelting, and an alloy liquid generated by smelting is cooled to obtain an alloy ingot; and the alloy ingot is overturned and is repeatedly smelted for four times to obtain a high-entropy alloy ingot; and
step 3, the high-entropy alloy ingot is sealed in an argon-filled quartz tube to be subjected to solution treatment at the temperature of 1200°C, and the temperature is kept for 12 h to obtain the high-entropy alloy Ti30Zr45Nb7Al8Hf10.
Embodiment 6
step 1, elements Ti, Zr, V, Nb, Al and Fe of which the purities are not smaller than 99.7wt% are adopted as raw materials, the raw materials are firstly polished by using a grinding wheel to remove oxide coatings on surfaces of the raw materials, and are then cleaned with anhydrous ethanol by ultrasonic oscillation, and clean raw materials with a total mass of (70±0.01) g are weighed according to an atomic percentage of Ti:Zr:V:Nb:Al:Fe=50:25:7:12:5:1;
step 2, the weighed raw materials are sequentially placed in a water-cooled copper crucible of a high-vacuum non-consumable electric arc smelting furnace according to melting points from low to high, then, vacuumization is performed, and after the vacuum degree in the smelting furnace reaches 2.5×10-3 Pa, and argon is filled as a protective gas; before the alloy is smelted, firstly, a pure metal titanium ingot is smelted to further reduce the content of oxygen in a furnace chamber of the smelting furnace, then, alloying smelting is performed, electromagnetic stirring is utilized for alloy homogenization during smelting, and an alloy liquid generated by smelting is cooled to obtain an alloy ingot; and the alloy ingot is overturned and is repeatedly smelted for four times to obtain a high-entropy alloy ingot; and
step 3, the high-entropy alloy ingot is sealed in an argon-filled quartz tube to be subjected to solution treatment at the temperature of 1000°C, and the temperature is kept for 12 h to obtain the high-entropy alloy Ti50Zr25V7Nb12Al5Fe1.
step 1, placing clean elemental raw materials Ti, Zr, V, Nb and M into a smelting furnace of which the vacuum degree is smaller than or equal to 2.5×10-3 Pa, and filling the smelting furnace with a protective gas; then, performing smelting, and cooling an alloy liquid generated by smelting to obtain an alloy ingot; and overturning the alloy ingot, and performing repeated smelting for more than three times to obtain a high-entropy alloy ingot; and
step 2, sealing the high-entropy alloy ingot in an argon-filled quartz tube, performing solution treatment at the temperature of 900-1200°C, and keeping the temperature for 1-12 h to obtain the high-entropy alloy.