High toughness mo / o-mab composite and method of making

Abstract

This invention discloses a high-strength and high-toughness Mo / o -MAB composite material, which contains 30%-50% by volume of o The composition consists of MAB phase particles, impurities not exceeding 0.1%, and the remainder being a pure Mo matrix, with the sum of the volume fractions of the above components being 100%. This invention also discloses a high-strength and high-toughness Mo / o The preparation method of -MAB composite materials includes a composite process of ball milling, mechanical alloying, hot pressing sintering, melting and heat treatment, crushing, re-ball milling, and spark plasma sintering. This method can precisely control the bonding between the Mo matrix and the composite material. o The distribution, volume fraction, and grain size of the -MAB phase were controlled to obtain a uniform dual-phase microstructure with low oxygen content. The continuous Mo matrix ensures good ductility and toughness in the composite material, while also exhibiting high elastic modulus and high hardness. o The MAB phase can enable composite materials to possess both high strength and high performance.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy technology, specifically relating to high strength and toughness Mo / o -MAB composite materials, the present invention also relates to high strength and toughness Mo / o - Preparation method of MAB composite material. Background Technology

[0002] The urgent need for improved gas turbine efficiency in the aerospace and energy sectors is driving breakthroughs in ultra-high temperature structural materials, pushing them towards service temperatures of 1300-1500℃. However, traditional nickel-based superalloys for turbine blades already have service temperatures reaching 1150℃, close to 90% of their melting point, making it difficult to meet the demands for further increases in operating temperature. This has become a core bottleneck restricting the performance upgrade of gas turbines. Molybdenum-based alloys, with their high melting points above 2000℃, possess the potential for ultra-high temperature applications. However, pure molybdenum easily forms volatile MoO3 above 500℃, severely limiting its service range in oxidizing environments. Mo-Si-B alloys are three-phase composite systems (containing α-Mo, Mo3Si, and Mo5SiB2) that achieve performance balance through the synergy of each phase. α-Mo provides room-temperature toughness, while Mo3Si and Mo5SiB2 ensure high-temperature strength and creep resistance. Simultaneously, Si and B elements can form a SiO2-B2O3 passivation film upon oxidation at high temperatures, significantly improving the alloy's oxidation resistance. Therefore, Mo-Si-B alloys have emerged as candidates for novel ultra-high temperature structural materials. However, insufficient room-temperature toughness and a mismatch between strength and toughness remain key challenges hindering their engineering applications. Studies have shown that increasing the α-Mo content can improve the room-temperature toughness of the alloy, but it significantly reduces the alloy's strength.

[0003] MAB phase materials are a class of layered ternary transition metal borides, where M is a transition metal element, A is a group IIIA or IVA element, and B is boron. The crystal structure of MAB phase materials consists of alternating MB and A atomic layers. MAB phases exhibit diverse chemical compositions and can display various crystal structures, including orthorhombic M… n+1 AB 2n (n=1) 3) Hexagonal crystal system M2AB2, monoclinic crystal system M n+1 AB n (n=1,2) and the tetragonal M5AB2 (also known as the T2 phase). Mo5SiB2 is a typical compound belonging to the T2 phase family, along with compounds of the same structure such as W5SiB2, Fe5SiB2, and Mn5SiB2. The T2 phase exhibits body-centered tetragonal symmetry, and its 32-atom unit cell has a space group of I4 / mcm The T2 phase possesses a variety of excellent properties, such as good oxidation resistance, thermal stability, tunable magnetism, and superconductivity.

[0004] By alloying the M or A sites of the T2 phase, the composition of the T2 phase can be expanded, thereby optimizing material properties. For example, the M sites of Fe5SiB2 can be alloyed with Co and Mn, and the A sites with P and S; similarly, the M sites of Mo5SiB2 can be alloyed with Ti, Zr, and Hf. However, early studies either explicitly assumed a solid solution or made no mention of it at all, failing to consider an ordered structure. Until recently, based on first-principles methods, a novel quaternary T2 phase has been expanded and confirmed by simultaneously considering the ordered distribution at both solid solution and two metal sites. This type of quaternary T2 phase is called an out-of-plane ordered MAB phase (MAB phase). o -MAB), with the general formula M′4M″SiB2, where M′ and M″ atoms occupy the 16l and 4c positions of the Wyckoff site, respectively, Si atoms occupy the 4a position, and B atoms occupy the 8h position. Therefore, researchers are attempting to develop refractory metal-based... o -MAB phases, for example: Joseph et al. successfully synthesized Mo4CrSiB2, W4CrSiB2 and Nb4CrSiB2. o -MAB phase and determined its lattice parameters; He et al. also synthesized Nb4VSiB2 and Mo4VSiB2, etc. o -MAB phase. Due to solid solution alloying elements, this type o -MAB phases typically possess high modulus, high hardness, and good electrical, thermal, and oxidation resistance properties.

[0005] For molybdenum-based composites, a continuous distribution of Mo can exert a toughening effect by crack trapping. Therefore, the microstructure characteristics developed are... o Composite materials with MAB phase dispersed in a continuous Mo matrix are expected to benefit from... o The strength advantage of the MAB phase synergistically improves the strength and toughness of molybdenum-based composite materials, meeting the urgent needs of high-temperature application environments. Summary of the Invention

[0006] The purpose of this invention is to provide high strength and toughness Mo / o -MAB composite material has a uniform and dense structure. o - The MAB phase is dispersed on a continuous Mo matrix, which can synergistically improve the strength and toughness of the composite material.

[0007] Another object of the present invention is to provide high strength and toughness Mo / o - Preparation method of MAB composite material.

[0008] The first technical solution adopted in this invention is a high-strength and tough Mo / o -MAB composite materials consist of the following components by volume percentage: 30%-50% o-MAB phase particles, no more than 0.1% impurities, the rest being pure Mo matrix, the sum of the volume fractions of the above components is 100%.

[0009] The first technical solution of the present invention is further characterized in that, o - The MAB phase particle size is 200nm-3.5um. o -MAB phase particles are uniformly dispersed in a pure Mo matrix.

[0010] o The expression for the -MAB phase is M′4M″SiB2. o -MAB belongs to I4 / mcm The space group is tetragonal, with M′ and M″ atoms occupying Wyckoff positions 16l and 4c respectively, Si atoms occupying 4a, and B atoms occupying 8h.

[0011] o In the -MAB phase, M′ is one of the elements Mo, Nb, and Ta, and M″ is one of the elements V and Cr.

[0012] The second technical solution adopted in this invention is a high-strength and tough Mo / o The method for preparing MAB composite materials is characterized by the following steps: Step 1: Weigh out M′ metal powder, M″ metal powder, Si powder, and B powder; Step 2: The M′ and M″ metal powders weighed in Step 1 are ball-milled and mechanically alloyed. The resulting powder is then ball-milled and mixed with Si and B powders to obtain a multi-component mixed powder. Step 3: The multi-component mixed powder obtained in Step 2 is sieved, then hot-pressed and sintered, followed by furnace cooling to obtain... o -MAB phase bulk materials; Step 4: Take the result from Step 3 o -The surface of the MAB phase bulk material is cleaned by grinding before it undergoes electric arc melting and high-temperature heat treatment. Step 5: Heat treat the product obtained in step 4. o -MAB phase bulk material is crushed and screened to obtain... o -MAB phase powder; Step 6: Weigh out the pure Mo powder and the powder obtained in Step 5. o -MAB phase powder ball milling and mixing; Step 7: Sinter the final mixed powder obtained in Step 6, then cool it in the furnace. After demolding, the high-strength and high-toughness Mo / o -MAB composite material.

[0013] The second technical solution of the present invention is further characterized in that, In step 1, M′ metal powder is selected from one of Mo, Nb and Ta powder, and M″ metal powder is selected from one of V and Cr powder. The purity of each component powder is ≥99.9wt% and the particle size is <50μm. The M′ metal powder, M″ metal powder, Si powder and B powder are weighed in a molar ratio of 4.0-4.2∶1.0-1.2∶1.0-1.2∶2-2.2.

[0014] The ball milling process in steps 2 and 6 is the same. A ball mill jar made of either agate or polyurethane is used. The grinding balls are made of agate or zirconium oxide. An argon atmosphere is introduced into the ball mill jar at a pressure of 0.3MPa-0.6MPa. During mixing, the ball-to-material ratio is 1-2:1, the ball mill speed is 300-400 r / min, and the ball milling time is 6-8 h. In the mechanical alloying process of step 2, the grinding jar and grinding balls are made of tungsten carbide to achieve the alloying effect of M′ and M″. The grinding time is 3-5 hours, the ball-to-material ratio is 5-10:1, the grinding mill speed is 150-200 r / min, and argon atmosphere is introduced into the grinding jar at a pressure of 0.3 MPa-0.6 MPa.

[0015] In step 3, a 200-300 mesh Taylor sieve is used for sieving. The graphite mold is then loaded into the mold for hot pressing and sintering. The hot pressing and sintering is carried out in a hot pressing and sintering furnace filled with Ar gas. The hot pressing and sintering process is divided into two steps: first, the temperature is raised from room temperature to 1200℃ at a heating rate of 5-10℃ / min, axial pressure is applied at 40-80MPa, and the temperature and pressure are maintained for 30-60min; then, the temperature is raised from 1200℃ to 1600-1700℃ at a heating rate of 5-10℃ / min, and the temperature and pressure are maintained for 2-3h; after that, the temperature and pressure are reduced and the furnace is cooled. In step 4, the arc melting is carried out in an arc melting furnace with an arc current of 800-900A. High-purity argon gas is introduced as a protective gas. After each melting, the sample is flipped over and melted again, for a total of 6-8 melting cycles. The high-temperature heat treatment is carried out in a vacuum resistance furnace, where the sample is held at 1600℃-1800℃ for 5-10 hours, with the vacuum level maintained at <6×10⁻⁶. -3 Pa.

[0016] In step 5, the crushing process is ball milling. The ball mill jar and grinding balls are made of tungsten carbide. The ball-to-material ratio is 8-10:1, the rotation speed is 150-220 r / min, the ball milling time is 2-5 h, and an Ar atmosphere is introduced during the ball milling process at a pressure of 0.3 MPa-0.6 MPa. The mixture is then screened through a 200-300 mesh Taylor sieve. In step 6, 50%-70% of pure Mo powder is weighed out by volume percentage, along with the amount obtained in step 5. o-MAB photochromic powder 30%-50%.

[0017] In step 7, spark plasma sintering is performed in a graphite mold. The temperature is raised from room temperature to 1400-1500℃ and held for 5-20 minutes. The heating rate is 30-70℃ / min, the axial pressure is 30-50MPa, and the vacuum degree is maintained at <6×10⁻⁶. -3 Pa, finally the temperature and pressure are reduced and cooled with the furnace.

[0018] The beneficial effects of this invention are high strength and toughness Mo / o -MAB composite material has a uniform and dense microstructure with fine Mo grain size. o The MAB phase is uniformly dispersed in the pure Mo matrix. Because... o - The alloying elements in MAB are solid-solution and exhibit an ordered layered arrangement. o The MAB phase possesses high modulus and high hardness, effectively hindering dislocation movement within the Mo matrix and improving the strength of the composite material. Therefore, due to... o The prominent strengthening effect of the MAB phase allows the Mo matrix to maintain a high volume fraction and continuity, thus enabling the Mo matrix to fully exert its passivation and bridging effects on cracks, resulting in a significant toughening effect. Furthermore, due to... o The presence of Si and B elements in the MAB phase allows for the formation of a continuous SiO2-B2O3 passivation film on the surface of the composite material after oxidation, while also ensuring its high-temperature oxidation resistance. This microstructure design provides new ideas and technical support for the preparation of high-performance refractory metal composite materials based on powder metallurgy. Compared to single arc melting or powder metallurgy methods, the composite process employed in this invention, involving ball milling, mechanical alloying, hot pressing sintering, melting and heat treatment, crushing, re-ball milling, and spark plasma sintering, precisely controls the volume fraction, distribution state, and grain size of each phase in the composite material, resulting in a uniform biphase microstructure with low oxygen content. The first stage of the preparation method (ball milling, mechanical alloying, hot pressing sintering, melting and heat treatment) ensures that the prepared... o The MAB phase exhibits uniform composition, high purity, and few impurities. The second stage of the preparation method (crushing, re-ball milling, and spark plasma sintering) can be effectively controlled. o -MAB grain size, improve o The dispersion of the MAB phase in the Mo matrix reduces the sintering temperature of the composite material and avoids the formation of defects at high temperatures. o The decomposition of the MAB phase or interdiffusion of elements with the Mo matrix inhibits excessive grain growth in the Mo matrix. The method of this invention is convenient to operate, low in cost, requires minimal equipment, and is easily industrialized. Attached Figure Description

[0019] Figure 1 The high strength and toughness Mo / prepared in Example 1o X-ray diffraction pattern of MAB composite material; Figure 2 The high strength and toughness Mo / prepared in Example 1 o - Scanning electron microscope image of MAB composite material; Figure 3 The high strength and toughness Mo / prepared in Example 1 o -Room temperature compressive stress-strain curves of MAB composites. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] This invention features high strength and toughness Mo / o -MAB composite material, composed of the following components by volume percentage: 30%-50% o -MAB phase particles, no more than 0.1% impurities, the rest being pure Mo matrix, the sum of the volume fractions of the above components is 100%.

[0022] o - The MAB phase particle size is 200nm-3.5um. o -MAB phase particles are uniformly dispersed in a pure Mo matrix.

[0023] o The expression for the -MAB phase is M′4M″SiB2. o -MAB belongs to I4 / mcm The space group is tetragonal, with M′ and M″ atoms occupying Wyckoff positions 16l and 4c respectively, Si atoms occupying 4a, and B atoms occupying 8h.

[0024] o In the -MAB phase, M′ is one of the elements Mo, Nb, and Ta, and M″ is one of the elements V and Cr.

[0025] This invention features high strength and toughness Mo / o The preparation method of MAB composite material is carried out according to the following steps: Step 1: Weigh out M′ metal powder, M″ metal powder, Si powder, and B powder; In step 1, M′ metal powder is selected from one of Mo, Nb and Ta powder, and M″ metal powder is selected from one of V and Cr powder. The purity of each component powder is ≥99.9wt% and the particle size is <50μm. The M′ metal powder, M″ metal powder, Si powder and B powder are weighed in a molar ratio of 4.0-4.2∶1.0-1.2∶1.0-1.2∶2-2.2.

[0026] Step 2: The M′ and M″ metal powders weighed in Step 1 are ball-milled and mechanically alloyed. The resulting powder is then ball-milled and mixed with Si and B powders to obtain a multi-component mixed powder. The ball milling process in steps 2 and 6 is the same. A ball mill jar made of either agate or polyurethane is used. The grinding balls are made of agate or zirconium oxide. An argon atmosphere is introduced into the ball mill jar at a pressure of 0.3MPa-0.6MPa. During mixing, the ball-to-material ratio is 1-2:1, the ball mill speed is 300-400 r / min, and the ball milling time is 6-8 h. In the mechanical alloying process of step 2, the grinding jar and grinding balls are made of tungsten carbide to achieve the alloying effect of M′ and M″. The grinding time is 3-5 hours, the ball-to-material ratio is 5-10:1, the grinding mill speed is 150-200 r / min, and argon atmosphere is introduced into the grinding jar at a pressure of 0.3 MPa-0.6 MPa.

[0027] Step 3: The multi-component mixed powder obtained in Step 2 is sieved, then hot-pressed and sintered, followed by furnace cooling to obtain... o -MAB phase bulk materials; In step 3, a 200-300 mesh Taylor sieve is used for sieving. The graphite mold is then loaded into the mold for hot pressing and sintering. The hot pressing and sintering is carried out in a hot pressing and sintering furnace filled with Ar gas. The hot pressing and sintering process is divided into two steps: first, the temperature is raised from room temperature to 1200℃ at a heating rate of 5-10℃ / min, axial pressure is applied at 40-80MPa, and the temperature and pressure are maintained for 30-60min; then, the temperature is raised from 1200℃ to 1600-1700℃ at a heating rate of 5-10℃ / min, and the temperature and pressure are maintained for 2-3h; after that, the temperature and pressure are reduced and the furnace is cooled. Step 4: Take the result from Step 3 o -The surface of the MAB phase bulk material is cleaned by grinding before it undergoes electric arc melting and high-temperature heat treatment. In step 4, the arc melting is carried out in an arc melting furnace with an arc current of 800-900A. High-purity argon gas is introduced as a protective gas. After each melting, the sample is flipped over and melted again, for a total of 6-8 melting cycles. The high-temperature heat treatment is carried out in a vacuum resistance furnace, where the sample is held at 1600℃-1800℃ for 5-10 hours, with the vacuum level maintained at <6×10⁻⁶. -3 Pa.

[0028] Step 5: Heat treat the product obtained in step 4. o -MAB phase bulk material is crushed and screened to obtain... o -MAB phase powder; Step 5 involves ball milling, using tungsten carbide jars and grinding balls. The ball-to-material ratio is 8-10:1, the rotation speed is 150-220 r / min, and the milling time is 2-5 h. During the milling process, an Ar atmosphere is introduced at a pressure of 0.3 MPa-0.6 MPa. The mixture is then screened through a 200-300 mesh Taylor sieve. Step 6: Weigh out the pure Mo powder and the powder obtained in Step 5. o -MAB phase powder ball milling and mixing; In step 6, weigh out 50%-70% of the pure Mo powder by volume percentage, and the powder obtained in step 5. o -MAB photochromic powder 30%-50%.

[0029] The ball milling process in step 6 is as follows: a ball mill jar made of either agate or polyurethane is used, and the grinding balls are made of agate or zirconium oxide. An argon atmosphere is introduced into the ball mill jar at a pressure of 0.3MPa-0.6MPa. During mixing, the ball-to-material ratio is 1-2:1, the ball mill speed is 300-400 r / min, and the ball milling time is 6-8 h.

[0030] Step 7: Sinter the final mixed powder obtained in Step 6, then cool it in the furnace. After demolding, the high-strength and high-toughness Mo / o -MAB composite material.

[0031] In step 7, spark plasma sintering is performed in a graphite mold. The temperature is raised from room temperature to 1400-1500℃ and held for 5-20 minutes. The heating rate is 30-70℃ / min, the axial pressure is 30-50MPa, and the vacuum degree is maintained at <6×10⁻⁶. -3 Pa, finally the temperature and pressure are reduced and cooled with the furnace.

[0032] Example 1 This invention features high strength and toughness Mo / o The preparation method of MAB composite material includes the following steps: Step 1: Weigh molybdenum powder, chromium powder, silicon powder and boron powder with a purity ≥99.9wt% and a particle size <50μm in a molar ratio of 4:1:1:2, i.e., 79.05g of molybdenum powder, 10.71g of chromium powder, 5.79g of silicon powder and 4.45g of boron powder.

[0033] Step 2: First, place the molybdenum powder and chromium powder weighed in Step 1 into a planetary ball mill for ball milling and mixing. The ball mill jar and grinding balls used in the ball milling process are made of agate. Argon atmosphere is introduced into the ball mill jar at a pressure of 0.3 MPa, the ball-to-powder ratio is 1:1, the ball mill speed is 300 r / min, and the ball milling time is 6 h. Then, the mixed powder is subjected to mechanical alloying treatment. The ball mill jar and grinding balls used are made of tungsten carbide, the ball milling time is 5 h, the ball-to-powder ratio is 10:1, the ball mill speed is 150 r / min, and argon atmosphere is introduced into the ball mill jar at a pressure of 0.3 MPa. The obtained powder is then ball milled and mixed again with silicon powder and boron powder to obtain a multi-component mixed powder. The ball milling process parameters are the same as above.

[0034] Step 3: After sieving the multi-component mixed powder obtained in Step 2 through a 200-mesh Taylor sieve, the powder is placed into a graphite mold for hot pressing sintering. The hot pressing sintering is carried out in a hot pressing sintering furnace filled with Ar gas, and the hot pressing sintering process is divided into two steps: First, the temperature is increased from room temperature to 1200℃ at a heating rate of 10℃ / min, axial pressure is applied to 40MPa, and the temperature and pressure are held for 60min. Then, the temperature is increased from 1200℃ to 1700℃ at a heating rate of 10℃ / min, and the temperature and pressure are held for 2h. After that, the temperature and pressure are reduced and the powder is cooled with the furnace to obtain the desired product. o -MAB phase bulk material.

[0035] Step 4, take the result from step 3 o - After the surface of the MAB phase bulk material was cleaned by grinding, it underwent arc melting and high-temperature heat treatment. Arc melting was carried out in an arc melting furnace with an arc current of 900A, and high-purity argon was introduced as a protective gas. After each melting, the sample was flipped over and melted again, for a total of 6 meltings. High-temperature heat treatment was carried out in a vacuum resistance furnace, where the sample was held at 1800℃ for 6 hours, and the vacuum degree was maintained <6×10 -3 Pa; Step 5: Heat treat the product obtained in step 4. o MAB phase bulk material was ball-milled using tungsten carbide jars and grinding balls at a ball-to-material ratio of 10:1, a rotation speed of 220 r / min, and a milling time of 5 h. An Ar atmosphere at a pressure of 0.3 MPa was introduced during the milling process. The material was then sieved through a 200-mesh Taylor sieve to obtain... o -MAB phase powder; Step 6: Weigh out 60% of the pure Mo powder and the amount obtained in Step 5 by volume percentage. o -40% MAB phase powder, and then perform final ball milling and mixing, with the ball milling and mixing parameters the same as in step 1; Step 7: Load the final mixed powder obtained in Step 6 into a graphite mold and sinter it in a spark plasma sintering furnace. The temperature is raised from room temperature to 1500℃ and held for 20 minutes. The heating rate is 30℃ / min, the axial pressure is 30MPa, and the vacuum degree is maintained <6×10⁻⁶. -3 Pa, then the temperature and pressure are reduced and cooled in the furnace, and finally demolded to obtain high-strength and tough Mo / o -MAB composite material.

[0036] Combination Figures 1-3 , Figure 1 The high strength and toughness Mo / prepared in this embodiment o X-ray diffraction pattern of MAB composite material; Figure 2 The high strength and toughness Mo / prepared in this embodiment o - Scanning electron microscope image of MAB composite material; Figure 3 The high strength and toughness Mo / prepared in this embodiment o -Room temperature compressive stress-strain curves of the MAB composite material. This high-strength and tough Mo / o The -MAB composite material contains 40 vol% Mo4CrSiB2 phase and 60 vol% Mo matrix. The Mo4CrSiB2 phase particles have a size of 200 nm-3.5 μm and are uniformly dispersed in the pure Mo matrix. Mechanical property test results show that this high-strength and tough Mo / o The MAB composite material has a compressive strength of 3125 MPa and a strain of 18.0%.

[0037] Example 2 This invention features high strength and toughness Mo / o The preparation method of MAB composite material includes the following steps: Step 1: Weigh molybdenum powder, vanadium powder, silicon powder and boron powder with a purity ≥99.9wt% and a particle size <50μm in a molar ratio of 4:1.1:1.1:2, i.e., 77.96g of molybdenum powder, 11.38g of vanadium powder, 6.27g of silicon powder and 4.39g of boron powder.

[0038] Step 2: First, place the molybdenum powder and vanadium powder weighed in Step 1 into a planetary ball mill for ball milling and mixing. The ball mill jar and grinding balls used in the ball milling are made of agate. Argon atmosphere is introduced into the ball mill jar at a pressure of 0.4 MPa, the ball-to-powder ratio is 1.5:1, the ball mill speed is 350 r / min, and the ball milling time is 7 h. Then, the mixed powder is mechanically alloyed. The ball mill jar and grinding balls used are made of tungsten carbide, the ball milling time is 4 h, the ball-to-powder ratio is 8:1, the ball mill speed is 180 r / min, and argon atmosphere is introduced into the ball mill jar at a pressure of 0.4 MPa. The obtained powder is then ball milled and mixed again with silicon powder and boron powder to obtain a multi-component mixed powder. The ball milling and mixing process parameters are the same as above.

[0039] Step 3: The multi-component mixed powder obtained in Step 2 is sieved through a 300-mesh Taylor sieve and then placed into a graphite mold for hot pressing sintering. The hot pressing sintering is carried out in a hot pressing sintering furnace filled with Ar gas, and the hot pressing sintering process is divided into two steps: First, the temperature is increased from room temperature to 1200℃ at a heating rate of 8℃ / min, axial pressure is applied to 50MPa, and the temperature and pressure are held for 60min; then the temperature is increased from 1200℃ to 1650℃ at a heating rate of 8℃ / min, and the temperature and pressure are held for 2.5h; after that, the temperature and pressure are reduced and the powder is cooled with the furnace to obtain the desired product. o -MAB phase bulk material.

[0040] Step 4, take the result from step 3 o - After the surface of the MAB phase bulk material was cleaned by grinding, it underwent arc melting and high-temperature heat treatment. Arc melting was carried out in an arc melting furnace with an arc current of 900A, and high-purity argon was introduced as a protective gas. After each melting, the sample was flipped over and melted again, for a total of 7 meltings. High-temperature heat treatment was carried out in a vacuum resistance furnace, where the sample was held at 1800℃ for 6 hours, and the vacuum degree was maintained <6×10 -3 Pa; Step 5: Heat treat the product obtained in step 4. o MAB phase bulk material was ball-milled using tungsten carbide jars and grinding balls at a ball-to-material ratio of 8:1, a rotation speed of 200 r / min, and a milling time of 5 h. An Ar atmosphere at a pressure of 0.4 MPa was introduced during the milling process. The material was then sieved through a 300-mesh Taylor sieve to obtain... o -MAB phase powder; Step 6: Weigh out 55% pure Mo powder and the amount obtained in Step 5 by volume percentage. o -45% MAB phase powder, and then perform final ball milling and mixing, with the ball milling and mixing parameters the same as in step 1; Step 7: Load the final mixed powder obtained in Step 6 into a graphite mold and sinter it in a spark plasma sintering furnace. The temperature is raised from room temperature to 1450℃ and held for 15 minutes. The heating rate is 40℃ / min, the axial pressure is 35MPa, and the vacuum degree is maintained <6×10⁻⁶. -3 Pa, then the temperature and pressure are reduced and cooled in the furnace, and finally demolded to obtain high-strength and tough Mo / o -MAB composite material.

[0041] This high-strength and tough Mo / o The -MAB composite material contains 45 vol% Mo4VSiB2 phase and 55 vol% Mo matrix. The Mo4VSiB2 phase particles have a size of 200 nm-3.5 μm and are uniformly dispersed in the pure Mo matrix. Mechanical property test results show that this high-strength and tough Mo / o The MAB composite material has a compressive strength of 3220 MPa and a strain of 15.2%.

[0042] Example 3 This invention Mo / o The preparation method of MAB composite material includes the following steps: Step 1: Weigh tantalum powder, chromium powder, silicon powder and boron powder with a purity ≥99.9wt% and a particle size <50μm in a molar ratio of 4:1.1:1.1:2, i.e. 86.84g of tantalum powder, 6.86g of chromium powder, 3.71g of silicon powder and 2.59g of boron powder.

[0043] Step 2: First, the tantalum powder and chromium powder weighed in Step 1 are placed in a planetary ball mill for ball milling and mixing. The ball mill jar and grinding balls used in the ball milling are made of agate. Argon atmosphere is introduced into the ball mill jar at a pressure of 0.5 MPa, the ball-to-powder ratio is 1:1, the ball mill speed is 400 r / min, and the ball milling time is 8 h. Then, the mixed powder is mechanically alloyed. The ball mill jar and grinding balls used are made of tungsten carbide, the ball milling time is 4 h, the ball-to-powder ratio is 7:1, the ball mill speed is 170 r / min, and argon atmosphere is introduced into the ball mill jar at a pressure of 0.5 MPa. The obtained powder is then ball milled and mixed again with silicon powder and boron powder to obtain a multi-component mixed powder. The ball milling and mixing process parameters are the same as above.

[0044] Step 3: After sieving the multi-component mixed powder obtained in Step 2 through a 300-mesh Taylor sieve, the powder is placed into a graphite mold for hot pressing sintering. The hot pressing sintering is carried out in a hot pressing sintering furnace filled with Ar gas, and the hot pressing sintering process is divided into two steps: First, the temperature is increased from room temperature to 1200℃ at a heating rate of 8℃ / min, axial pressure is applied to 60MPa, and the temperature and pressure are held for 40min. Then, the temperature is increased from 1200℃ to 1700℃ at a heating rate of 8℃ / min, and the temperature and pressure are held for 3h. After that, the temperature and pressure are reduced and the powder is cooled with the furnace to obtain the desired product. o -MAB phase bulk material.

[0045] Step 4, take the result from step 3 o - After the surface of the MAB phase bulk material was cleaned by grinding, it underwent arc melting and high-temperature heat treatment. Arc melting was carried out in an arc melting furnace with an arc current of 850A, and high-purity argon was introduced as a protective gas. After each melting, the sample was turned over and melted again, for a total of 6 meltings. High-temperature heat treatment was carried out in a vacuum resistance furnace, where the sample was held at 1700℃ for 7 hours, and the vacuum degree was maintained at <6×10 -3 Pa; Step 5: Heat treat the product obtained in step 4. oMAB phase bulk material was ball-milled using tungsten carbide jars and grinding balls at a ball-to-material ratio of 8:1, a rotation speed of 220 r / min, and a milling time of 5 h. An Ar atmosphere at a pressure of 0.5 MPa was introduced during the milling process. The material was then sieved through a 300-mesh Taylor sieve to obtain... o -MAB phase powder; Step 6: Weigh out 60% of the pure Mo powder and the amount obtained in Step 5 by volume percentage. o -40% MAB phase powder, and then perform final ball milling and mixing, with the ball milling and mixing parameters the same as in step 1; Step 7: Load the final mixed powder obtained in Step 6 into a graphite mold and sinter it in a spark plasma sintering furnace. The temperature is raised from room temperature to 1500℃ and held for 10 minutes. The heating rate is 50℃ / min, the axial pressure is 50MPa, and the vacuum degree is maintained <6×10⁻⁶. -3 Pa, then the temperature and pressure are reduced and cooled in the furnace, and finally demolded to obtain high-strength and tough Mo / o -MAB composite material.

[0046] This high-strength and tough Mo / o The MAB composite material contains 40 vol% Ta4CrSiB2 phase and 60 vol% Mo matrix. The Ta4CrSiB2 phase particles have a size of 200 nm to 3.5 μm and are uniformly dispersed within the pure Mo matrix. Mechanical property test results show that this high-strength and high-toughness Mo / o The MAB composite material has a compressive strength of 3084 MPa and a strain of 17.5%.

[0047] Example 4 This invention features high strength and toughness Mo / o The preparation method of MAB composite material includes the following steps: Step 1: Weigh niobium powder, chromium powder, silicon powder and boron powder with a purity ≥99.9wt% and a particle size <50μm in a molar ratio of 4:1:1:2, i.e. 78.51g of niobium powder, 10.99g of chromium powder, 5.93g of silicon powder and 4.57g of boron powder.

[0048] Step 2: First, the niobium powder and chromium powder weighed in Step 1 are placed in a planetary ball mill for ball milling and mixing. The ball mill jar and grinding balls used in the ball milling are made of agate. Argon atmosphere is introduced into the ball mill jar at a pressure of 0.5 MPa, the ball-to-powder ratio is 2:1, the ball mill speed is 400 r / min, and the ball milling time is 8 h. Then, the mixed powder is mechanically alloyed. The ball mill jar and grinding balls used are made of tungsten carbide, the ball milling time is 5 h, the ball-to-powder ratio is 5:1, the ball mill speed is 180 r / min, and argon atmosphere is introduced into the ball mill jar at a pressure of 0.5 MPa. The obtained powder is then ball milled and mixed again with silicon powder and boron powder to obtain a multi-component mixed powder. The ball milling and mixing process parameters are the same as above.

[0049] Step 3: After sieving the multi-component mixed powder obtained in Step 2 through a 300-mesh Taylor sieve, the powder is placed into a graphite mold for hot pressing sintering. The hot pressing sintering is carried out in a hot pressing sintering furnace filled with Ar gas, and the hot pressing sintering process is divided into two steps: First, the temperature is increased from room temperature to 1200℃ at a heating rate of 10℃ / min, axial pressure is applied to 70MPa, and the temperature and pressure are held for 40min. Then, the temperature is increased from 1200℃ to 1700℃ at a heating rate of 10℃ / min, and the temperature and pressure are held for 2.5h. After that, the temperature and pressure are reduced and the powder is cooled with the furnace to obtain the desired product. o -MAB phase bulk material.

[0050] Step 4, take the result from step 3 o - After the surface of the MAB phase bulk material was cleaned by grinding, it underwent arc melting and high-temperature heat treatment. Arc melting was carried out in an arc melting furnace with an arc current of 800A and high-purity argon gas as a protective gas. After each melting, the sample was flipped over and melted again, for a total of 8 melting cycles. High-temperature heat treatment was carried out in a vacuum resistance furnace, where the sample was held at 1800℃ for 10 hours with a vacuum level maintained at <6×10⁻⁶. -3 Pa; Step 5: Heat treat the product obtained in step 4. o MAB phase bulk material was ball-milled using tungsten carbide jars and grinding balls at a ball-to-material ratio of 10:1, a rotation speed of 180 r / min, and a milling time of 5 h. An Ar atmosphere at a pressure of 0.5 MPa was introduced during the milling process. The material was then sieved through a 300-mesh Taylor sieve to obtain... o -MAB phase powder; Step 6: Weigh out 55% pure Mo powder and the amount obtained in Step 5 by volume percentage. o -45% MAB phase powder, and then perform final ball milling and mixing, with the ball milling and mixing parameters the same as in step 1; Step 7: Load the final mixed powder obtained in Step 6 into a graphite mold and sinter it in a spark plasma sintering furnace. The temperature is raised from room temperature to 1450℃ and held for 10 minutes. The heating rate is 60℃ / min, the axial pressure is 50MPa, and the vacuum degree is maintained <6×10⁻⁶. -3 Pa, then the temperature and pressure are reduced and cooled in the furnace, and finally demolded to obtain high-strength and tough Mo / o -MAB composite material.

[0051] This high-strength and tough Mo / o The MAB composite material contains 45 vol% Nb4CrSiB2 phase and 55 vol% Mo matrix. The Nb4CrSiB2 phase particles have a size of 200 nm-3.5 μm and are uniformly dispersed in the pure Mo matrix. Mechanical property test results show that this high-strength and high-toughness Mo / o The MAB composite material has a compressive strength of 3267 MPa and a strain of 14.6%.

[0052] Example 5 This invention features high strength and toughness Mo / o The preparation method of MAB composite material includes the following steps: Step 1: Weigh niobium powder, vanadium powder, silicon powder and boron powder with a purity ≥99.9wt% and a particle size <50μm in a molar ratio of 4:1:1:2, i.e., 78.69g of niobium powder, 10.79g of vanadium powder, 5.95g of silicon powder and 4.58g of boron powder.

[0053] Step 2: First, the niobium powder and vanadium powder weighed in Step 1 are placed in a planetary ball mill for ball milling and mixing. The ball mill jar and grinding balls used in the ball milling are made of agate. Argon atmosphere is introduced into the ball mill jar at a pressure of 0.6 MPa, the ball-to-powder ratio is 2:1, the ball mill speed is 400 r / min, and the ball milling time is 8 h. Then, the mixed powder is mechanically alloyed. The ball mill jar and grinding balls used are made of tungsten carbide, the ball milling time is 5 h, the ball-to-powder ratio is 5:1, the ball mill speed is 150 r / min, and argon atmosphere is introduced into the ball mill jar at a pressure of 0.6 MPa. The obtained powder is then ball milled and mixed again with silicon powder and boron powder to obtain a multi-component mixed powder. The ball milling and mixing process parameters are the same as above.

[0054] Step 3: After sieving the multi-component mixed powder obtained in Step 2 through a 200-300 mesh Taylor sieve, the powder is placed into a graphite mold for hot pressing sintering. The hot pressing sintering is carried out in a hot pressing sintering furnace filled with Ar gas, and the hot pressing sintering process is divided into two steps: First, the temperature is increased from room temperature to 1200℃ at a heating rate of 5℃ / min, axial pressure is applied to 80MPa, and the temperature and pressure are held for 30min. Then, the temperature is increased from 1200℃ to 1700℃ at a heating rate of 5℃ / min, and the temperature and pressure are held for 3h. After that, the temperature and pressure are reduced and the powder is cooled with the furnace to obtain the desired product.o -MAB phase bulk material.

[0055] Step 4, take the result from step 3 o - After the surface of the MAB phase bulk material was cleaned by grinding, it underwent arc melting and high-temperature heat treatment. Arc melting was carried out in an arc melting furnace with an arc current of 900A, and high-purity argon was introduced as a protective gas. After each melting, the sample was flipped over and melted again, for a total of 7 melting cycles. High-temperature heat treatment was carried out in a vacuum resistance furnace, where the sample was held at 1800℃ for 8 hours, and the vacuum degree was maintained at <6×10⁻⁶. -3 Pa; Step 5: Heat treat the product obtained in step 4. o MAB phase bulk material was ball-milled using tungsten carbide jars and grinding balls at a ball-to-material ratio of 8:1, a rotation speed of 200 r / min, and a milling time of 3 h. An Ar atmosphere at a pressure of 0.6 MPa was introduced during the milling process. The material was then sieved through a 300-mesh Taylor sieve to obtain... o -MAB phase powder; Step 6: Weigh out 60% of the pure Mo powder and the amount obtained in Step 5 by volume percentage. o -40% MAB phase powder, and then perform final ball milling and mixing, with the ball milling and mixing parameters the same as in step 1; Step 7: Load the final mixed powder obtained in Step 6 into a graphite mold and sinter it in a spark plasma sintering furnace. The temperature is raised from room temperature to 1500℃ and held for 10 minutes. The heating rate is 70℃ / min, the axial pressure is 40MPa, and the vacuum degree is maintained <6×10⁻⁶. -3 Pa, then the temperature and pressure are reduced and cooled in the furnace, and finally demolded to obtain high-strength and tough Mo / o -MAB composite material.

[0056] This high-strength and tough Mo / o The MAB composite material contains 40 vol% Nb4VSiB2 phase and 60 vol% Mo matrix. The Nb4VSiB2 phase particles have a size of 200 nm-3.5 μm and are uniformly dispersed in the pure Mo matrix. Mechanical property test results show that this high-strength and tough Mo / o The MAB composite material has a compressive strength of 3210 MPa and a strain of 17.3%.

[0057] Example 6 This invention features high strength and toughness Mo / o The preparation method of MAB composite material includes the following steps: Step 1: Weigh tantalum powder, vanadium powder, silicon powder and boron powder with a purity ≥99.9wt% and a particle size <50μm in a molar ratio of 4:1.1:1.1:2, i.e. 86.96g of tantalum powder, 6.73g of vanadium powder, 3.71g of silicon powder and 2.60g of boron powder.

[0058] Step 2: First, place the tantalum powder and vanadium powder weighed in Step 1 into a planetary ball mill for ball milling and mixing. The ball mill jar and grinding balls used in the ball milling are made of agate. Argon atmosphere is introduced into the ball mill jar at a pressure of 0.5 MPa, the ball-to-powder ratio is 1:1, the ball mill speed is 350 r / min, and the ball milling time is 7 h. Then, the mixed powder is mechanically alloyed. The ball mill jar and grinding balls used are made of tungsten carbide, the ball milling time is 3 h, the ball-to-powder ratio is 8:1, the ball mill speed is 180 r / min, and argon atmosphere is introduced into the ball mill jar at a pressure of 0.5 MPa. The obtained powder is then ball milled and mixed again with silicon powder and boron powder to obtain a multi-component mixed powder. The ball milling and mixing process parameters are the same as above.

[0059] Step 3: After sieving the multi-component mixed powder obtained in Step 2 through a 200-300 mesh Taylor sieve, the powder is placed into a graphite mold for hot pressing sintering. The hot pressing sintering is carried out in a hot pressing sintering furnace filled with Ar gas, and the hot pressing sintering process is divided into two steps: First, the temperature is increased from room temperature to 1200℃ at a heating rate of 8℃ / min, axial pressure is applied to 70MPa, and the temperature and pressure are held for 40min; then, the temperature is increased from 1200℃ to 1700℃ at a heating rate of 8℃ / min, and the temperature and pressure are held for 2.5h. After that, the temperature and pressure are reduced and the powder is cooled with the furnace to obtain the desired product. o -MAB phase bulk material.

[0060] Step 4, take the result from step 3 o - After the surface of the MAB phase bulk material was cleaned by grinding, it underwent arc melting and high-temperature heat treatment. Arc melting was carried out in an arc melting furnace with an arc current of 800A and high-purity argon gas as a protective gas. After each melting, the sample was flipped over and melted again, for a total of 8 melting cycles. High-temperature heat treatment was carried out in a vacuum resistance furnace, where the sample was held at 1750℃ for 8 hours with a vacuum level maintained <6×10⁻⁶. -3 Pa; Step 5: Heat treat the product obtained in step 4. o MAB phase bulk material was ball-milled using tungsten carbide jars and grinding balls at a ball-to-material ratio of 10:1, a rotation speed of 220 r / min, and a milling time of 3.5 h. An Ar atmosphere at a pressure of 0.5 MPa was introduced during the milling process, and the material was then sieved through a 300-mesh Taylor sieve to obtain... o -MAB phase powder; Step 6: Weigh out 55% pure Mo powder and the amount obtained in Step 5 by volume percentage. o-45% MAB phase powder, and then perform final ball milling and mixing, with the ball milling and mixing parameters the same as in step 1; Step 7: Load the final mixed powder obtained in Step 6 into a graphite mold and sinter it in a spark plasma sintering furnace. The temperature is raised from room temperature to 1500℃ and held for 15 minutes. The heating rate is 70℃ / min, the axial pressure is 40MPa, and the vacuum degree is maintained <6×10⁻⁶. -3 Pa, then the temperature and pressure are reduced and cooled in the furnace, and finally demolded to obtain high-strength and tough Mo / o -MAB composite material.

[0061] This high-strength and tough Mo / o The MAB composite material contains 45 vol% Ta4VSiB2 phase and 55 vol% Mo matrix. The Ta4VSiB2 phase particles have a size of 200 nm-3.5 μm and are uniformly dispersed in the pure Mo matrix. Mechanical property test results show that this high-strength and tough Mo / o The MAB composite material has a compressive strength of 3356 MPa and a strain of 12.9%.

Claims

1. High strength and toughness Mo / o -MAB composite material, characterized in that Composed of the following components by volume percentage: 30%-50% o -MAB phase particles, no more than 0.1% impurities, the rest being pure Mo matrix, the sum of the volume fractions of the above components is 100%.

2. The high strength and toughness Mo / as described in claim 1 o -MAB composite material, characterized in that The o - The MAB phase particle size is 200nm-3.5um. o -MAB phase particles are uniformly dispersed in a pure Mo matrix.

3. The high-strength and high-toughness Mo / as described in claim 1 o -MAB composite material, characterized in that The o The expression for the -MAB phase is M′4M″SiB2. o -MAB belongs to I4 / mcm The space group is tetragonal, with M′ and M″ atoms occupying Wyckoff positions 16l and 4c respectively, Si atoms occupying 4a, and B atoms occupying 8h.

4. The high strength and toughness Mo / as described in claim 1 o -MAB composite material, characterized in that The o In the -MAB phase, M′ is one of the elements Mo, Nb, and Ta, and M″ is one of the elements V and Cr.

5. High strength and toughness Mo / o The method for preparing MAB composite material is characterized by, The specific steps are as follows: Step 1: Weigh out M′ metal powder, M″ metal powder, Si powder, and B powder; Step 2: The M′ and M″ metal powders weighed in Step 1 are ball-milled and mechanically alloyed. The resulting powder is then ball-milled and mixed with Si and B powders to obtain a multi-component mixed powder. Step 3: The multi-component mixed powder obtained in Step 2 is sieved, then hot-pressed and sintered, followed by furnace cooling to obtain... o -MAB phase bulk materials; Step 4: Take the result from Step 3 o -The surface of the MAB phase bulk material is cleaned by grinding before it undergoes electric arc melting and high-temperature heat treatment. Step 5: Heat treat the product obtained in step 4. o -MAB phase bulk material is crushed and screened to obtain... o -MAB phase powder; Step 6: Weigh out the pure Mo powder and the powder obtained in Step 5. o -MAB phase powder ball milling and mixing; Step 7: Sinter the final mixed powder obtained in Step 6, then cool it in the furnace. After demolding, the high-strength and high-toughness Mo / o -MAB composite material.

6. The high strength and toughness Mo / according to claim 5 o The method for preparing MAB composite material is characterized by, In step 1, M′ metal powder is selected from one of Mo, Nb and Ta powder, and M″ metal powder is selected from one of V and Cr powder. The purity of each component powder is ≥99.9wt% and the particle size is <50μm. M′ metal powder, M″ metal powder, Si powder and B powder are weighed in a molar ratio of 4.0-4.2∶1.0-1.2∶1.0-1.2∶2-2.

2.

7. The high strength and toughness Mo / according to claim 5 o The method for preparing MAB composite material is characterized by, The ball milling process in steps 2 and 6 is the same. A ball mill jar made of either agate or polyurethane is used, and the grinding balls are made of agate or zirconium oxide. An argon atmosphere is introduced into the ball mill jar at a pressure of 0.3MPa-0.6MPa. During mixing, the ball-to-material ratio is 1-2:1, the ball mill speed is 300-400 r / min, and the ball milling time is 6-8 h. In the mechanical alloying process of step 2, the grinding jar and grinding balls are made of tungsten carbide to achieve the alloying effect of M′ and M″. The grinding time is 3-5 hours, the ball-to-material ratio is 5-10:1, the grinding mill speed is 150-200 r / min, and argon atmosphere is introduced into the grinding jar at a pressure of 0.3 MPa-0.6 MPa.

8. The high strength and toughness Mo / according to claim 5 o The method for preparing MAB composite material is characterized by, In step 3, a 200-300 mesh Taylor sieve is used for sieving. The graphite mold is then loaded for hot pressing and sintering. The hot pressing and sintering is carried out in a hot pressing and sintering furnace filled with Ar gas. The hot pressing and sintering process is divided into two steps: first, the temperature is raised from room temperature to 1200℃ at a heating rate of 5-10℃ / min, axial pressure is applied at 40-80MPa, and the temperature and pressure are maintained for 30-60min; then, the temperature is raised from 1200℃ to 1600-1700℃ at a heating rate of 5-10℃ / min, and the temperature and pressure are maintained for 2-3h; after that, the temperature and pressure are reduced and the furnace is cooled. The arc melting in step 4 is carried out in an arc melting furnace, the arc current is 800-900 A, high-purity argon is introduced as the protective gas, the sample is turned over after each melting and is melted again, a total of 6-8 times, the high-temperature heat treatment is carried out in a vacuum resistance furnace, the sample is kept at a temperature of 1600-1800 °C for 5-10 h, the vacuum degree is kept <6x10 -3 Pa.

9. The high strength and toughness Mo / according to claim 5 o The method for preparing MAB composite material is characterized by, In step 5, the crushing process is ball milling. The ball mill jar and grinding balls are made of tungsten carbide. The ball-to-material ratio is 8-10:1, the rotation speed is 150-220 r / min, the ball milling time is 2-5 h, and an Ar atmosphere is introduced during the ball milling process at a pressure of 0.3 MPa-0.6 MPa. The mixture is then sieved through a 200-300 mesh Taylor sieve. In step 6, 50%-70% of pure Mo powder is weighed out by volume percentage, along with the amount obtained in step 5. o -MAB photochromic powder 30%-50%.

10. The high strength and toughness Mo / according to claim 5 o The method for preparing MAB composite material is characterized by, In step 7, spark plasma sintering is performed in a graphite mold. The temperature is raised from room temperature to 1400-1500℃ and held for 5-20 minutes. The heating rate is 30-70℃ / min, the axial pressure is 30-50MPa, and the vacuum degree is maintained <6×10⁻⁶. -3 Pa, finally the temperature and pressure are reduced and cooled with the furnace.

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