Processing method of high-density molybdenum alloy product

Abstract

The invention discloses a processing method of a high-density molybdenum alloy product. The processing method specifically comprises the following steps: step 1, selecting a molybdenum powder raw material; 2, the raw materials selected in the step 1 are mixed, and after mixing, ball materials are separated to obtain molybdenum pre-alloy powder; 3, the molybdenum pre-alloy powder obtained in the step 2 is loaded into a rubber sleeve to be machined, and a molybdenum alloy fine trimming blank is obtained; 4, the molybdenum alloy fine fettling blank is put into a mold to be sintered, and a molybdenum alloy sintered blank is obtained; and 5, the molybdenum alloy product obtained in the step 4 is subjected to polishing treatment, cleaning and drying, and then the molybdenum alloy product is obtained. According to the method, the problems of low density and low material utilization rate of an existing high-density molybdenum alloy product processing method are solved.

Description

Technical Field

[0001] This invention belongs to the field of molybdenum alloy preparation and processing technology, and relates to a processing method for high-density molybdenum alloy products. Background Technology

[0002] Molybdenum alloy plates, with their high melting point, excellent creep resistance, corrosion resistance, and high-temperature strength, play an irreplaceable role in many cutting-edge industrial fields. For example, molybdenum alloy plates can be used to manufacture high-temperature components such as jet engine combustor liners and turbine guide vanes, capable of withstanding operating environments above 1600°C and ensuring dimensional stability under extreme conditions. Molybdenum alloy plates (such as TZM alloy) are used as nozzle materials in rocket engines, resisting the erosion of high-temperature exhaust gases, and their low coefficient of thermal expansion reduces thermal stress cracking. Molybdenum-niobium alloy plates (such as the Hastelloy series) are used in reaction vessels for highly corrosive media such as sulfuric acid and hydrochloric acid, with a service life more than three times longer than stainless steel.

[0003] Molybdenum alloy targets are high-performance sputtering materials, primarily used to form thin films on substrate surfaces via magnetron sputtering technology, and are widely applied in high-tech fields. For example, molybdenum alloy targets can improve conductivity and adhesion, reduce signal delay, and are used in liquid crystal display (LCD) and organic light-emitting diode (OLED) panels. High-purity molybdenum-niobium alloys (Mo-Nb) and molybdenum-tantalum alloys (Mo-Ta), due to their excellent corrosion resistance and conductivity, are particularly suitable for metal interconnects in integrated circuits and electrode layers in foldable and curved screens. Mo-Re alloys, with their low thermal conductivity and ablation resistance, are widely used in the nuclear industry, aerospace, defense, and high-temperature structural materials.

[0004] Molybdenum alloy plate targets are primarily prepared using powder metallurgy, typically involving pressing, sintering for densification, rolling, and machining. In traditional molybdenum alloy preparation, the powder is cold isostatically pressed. However, due to the easily deformable rubber sheath, the deformation is uneven, making it difficult to achieve a regular shape after medium-frequency sintering. Furthermore, the density of the powder metallurgy-processed products after medium-frequency sintering often fails to meet the requirements for target application, necessitating pressure processing to further improve density and meet the final product's performance requirements. Summary of the Invention

[0005] The purpose of this invention is to provide a processing method for high-density molybdenum alloy products, which solves the problems of low density and low material utilization in existing processing methods for high-density molybdenum alloy products.

[0006] The technical solution adopted in this invention is a processing method for high-density molybdenum alloy products, which specifically includes the following steps: Step 1: Select molybdenum powder raw materials; Step 2: Mix the raw materials selected in Step 1, and then separate the spherical material to obtain molybdenum pre-alloyed powder; Step 3: The molybdenum pre-alloyed powder obtained in Step 2 is loaded into a rubber sleeve for processing to obtain a molybdenum alloy finished billet; Step 4: Place the finished molybdenum alloy billet into a mold for sintering to obtain a sintered molybdenum alloy billet. Step 5: Polish the molybdenum alloy obtained in Step 4, clean and dry it to obtain the molybdenum alloy product.

[0007] The invention is further characterized by: The specific process of step 1 is as follows: When the raw material is pure molybdenum powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; and the molybdenum powder with a particle size distribution D50 of 5~8μm is identified as raw material C. The specific process of step 2 is as follows: raw materials A, B and C are mixed and used as the grading raw materials for molybdenum powder. They are added to a vacuum three-dimensional mixer and mixed under vacuum or argon atmosphere for 1 to 4 hours. At the same time, pure molybdenum balls are added at a ball-to-material mass ratio of 1:10 to 20. After mixing, the balls are separated to obtain molybdenum pre-alloyed powder.

[0008] The specific process of step 1 is as follows: When the raw material is a molybdenum-rhenium mixed powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; the molybdenum powder with a particle size distribution D50 of 5~8μm is identified as raw material C; and the pure rhenium powder with a particle size distribution D50 of 20~30μm is identified as raw material D. The specific process of step 2 is as follows: raw materials A, B, C and D are mixed and used as the grading raw materials for molybdenum powder. They are added to a vacuum three-dimensional mixer and mixed under vacuum or argon atmosphere for 1 to 4 hours. At the same time, pure molybdenum balls are added at a ball-to-material mass ratio of 1:10 to 20. After mixing, the balls are separated to obtain molybdenum pre-alloyed powder.

[0009] The specific process of step 1 is as follows: When the raw material is TZM mixed powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; the molybdenum powder with a particle size distribution D50 of 5~8μm is identified as raw material C; the titanium hydride powder is identified as raw material D; the zirconium hydride powder is identified as raw material E; and the graphite powder is identified as raw material F. The specific process of step 2 is as follows: Step 2.1: Weigh raw materials C, D, E and F respectively, add raw materials C, D, E and F into a three-dimensional mixer, and mix under vacuum or argon atmosphere for 1-4 hours. At the same time, add pure molybdenum balls at a ball-to-material mass ratio of 1:10-20. After mixing, separate the ball-to-material to obtain primary molybdenum pre-alloyed powder A. Step 2.2: Weigh raw material A, raw material B, raw material C, and primary molybdenum pre-alloyed powder respectively. Add raw material A, raw material B, raw material C, and primary molybdenum pre-alloyed powder to a three-dimensional mixer and mix under vacuum or argon atmosphere for 1-4 hours. At the same time, add pure molybdenum balls at a ball-to-material mass ratio of 1:10-20. After mixing, separate the balls to obtain molybdenum pre-alloyed powder.

[0010] The specific process of step 1 is as follows: When the raw material is a molybdenum-niobium mixed powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; and the pure niobium powder with a particle size distribution D50 of 10~15μm is identified as raw material C. The specific process of step 2 is as follows: Raw materials A, B, and C are mixed and used as the grading raw materials for molybdenum powder. They are then added to a vacuum three-dimensional mixer and mixed under vacuum or argon atmosphere for 1-4 hours. At the same time, pure molybdenum balls are added at a ball-to-material mass ratio of 1:10-20. After mixing, the balls are separated to obtain molybdenum pre-alloyed powder.

[0011] The specific process of step 1 is as follows: When the raw material is a molybdenum-tantalum mixed powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; the molybdenum powder with a particle size distribution D50 of 5~8μm is identified as raw material C; and the pure tantalum with a particle size distribution D50 of 5~8μm is identified as raw material D. The specific process of step 2 is as follows: Raw materials A, B, C and D are mixed and used as the grading raw materials for molybdenum powder. They are then added to a vacuum three-dimensional mixer and mixed under vacuum or argon atmosphere for 1 to 4 hours. At the same time, pure molybdenum balls are added at a ball-to-material mass ratio of 1:10 to 20. After mixing, the balls are separated to obtain molybdenum pre-alloyed powder.

[0012] The specific process of step 3 is as follows: the molybdenum pre-alloyed powder obtained in step 2 is loaded into a rubber sleeve, sealed, and then pressed using a cold isostatic press at a pressure of 150MPa~200MPa and a holding time of 5min~10min to obtain a molybdenum alloy blank. The obtained molybdenum alloy blank is then cut to obtain a molybdenum alloy precision blank.

[0013] The specific process of step 4 is as follows: Place the refined molybdenum alloy billet into a graphite mold of the appropriate size, then place the graphite mold in the sintering zone of the vacuum hot press furnace, adjust the distance between the upper and lower pressure heads until they just touch, start the sintering program, and obtain the sintered molybdenum alloy billet.

[0014] In step 4, the specific sintering process is as follows: first, a vacuum is drawn until the vacuum degree reaches 10. -2 ~10 -3The temperature is raised starting at Pa, with the heating rate maintained at 10℃ / min to 80℃ / min. After 60min to 180min, the temperature reaches 1400℃ to 1800℃. Then, pressure is gradually applied, with the pressurization rate controlled at 2MPa to 10MPa / min, and the final pressure is 20MPa to 80MPa. The holding time is 20min to 120min. After the holding time is completed, the pressure is released directly, and the cooling rate is maintained at 50℃ / min to 200℃ / min. After cooling, the molybdenum alloy sintered billet is obtained after demolding.

[0015] The beneficial effects of this invention are that it utilizes a powder gradation + vacuum high-temperature molding method, which is characterized by high material utilization, small processing allowance, and near-net-shape forming. At the same time, it has high density of finished products after one-time sintering, which can be directly processed into molybdenum alloy plates and targets for application without the need for rolling processing, thus saving production costs. Attached Figure Description

[0016] Figure 1 This is a metallographic schematic diagram (×200) of a pure molybdenum plate obtained in Example 1 of the high-density molybdenum alloy product processing method of the present invention. Figure 2 This is a schematic diagram of the metallographic structure of the TZM plate obtained in Example 3 of the high-density molybdenum alloy product processing method of the present invention; Figure 3 This is a schematic diagram of the metallographic structure of the molybdenum-tantalum plate obtained in Example 4 of the high-density molybdenum alloy product processing method of the present invention; Figure 4 This is a schematic diagram of the metallographic structure of the molybdenum-niobium plate obtained in Example 5 of the high-density molybdenum alloy product processing method of the present invention. Detailed Implementation

[0017] The following detailed description is provided in conjunction with specific implementation methods.

[0018] The method for processing high-density molybdenum alloy products according to the present invention specifically includes the following steps: Step 1: Select molybdenum powder raw materials; Raw materials are selected according to the actual product requirements. For example, the particle size distribution of molybdenum powder raw materials is tested in batches. Molybdenum powder with a particle size distribution D50 of 20~30μm is determined as raw material A; molybdenum powder with a particle size distribution D50 of 10~15μm is determined as raw material B; and molybdenum powder with a particle size distribution D50 of 5~8μm is determined as raw material C. Step 2: Mix the raw materials selected in Step 1, and then separate the spherical particles to obtain molybdenum pre-alloyed powder. Specifically: Raw materials A, B, and C are mixed at a mass percentage of 50%, 10%, and 40% respectively to serve as the grading raw materials for molybdenum powder. Then, they are added to a vacuum three-dimensional mixer in the corresponding proportions and mixed under vacuum or argon for 1-4 hours. At the same time, pure molybdenum spheres are added at a sphere-to-particle mass ratio of 1:10-20. After mixing, the spherical particles are separated to obtain molybdenum pre-alloyed powder. Step 3: The molybdenum pre-alloyed powder obtained in Step 2 is loaded into a rubber sleeve for processing. After sealing, it is pressed using a cold isostatic press at a pressure of 150MPa~200MPa and a holding time of 5min~10min to obtain a molybdenum alloy blank. The molybdenum alloy blank is then cut and finished (milled and turned) according to the finished product size, with a thickness of 130% of the finished product size and a allowance of 105% of the finished product size in other directions, to obtain a finished molybdenum alloy blank. Step 4: Place the finished molybdenum alloy billet into a graphite mold of appropriate size, separating the contact surface with the mold with graphite paper to prevent sticking and facilitate demolding. Then, place the graphite mold in the sintering zone of the vacuum hot press furnace, adjusting the distance between the upper and lower pressure heads until they are just touching. Start the sintering program, first drawing a vacuum until the vacuum level reaches 10... -2 ~10 -3 Heating begins at Pa, with the heating rate maintained at 10℃~80℃ / min. After 60min-180min, the temperature reaches 1400℃-1800℃, after which pressure is gradually applied at a rate of 2MPa-10MPa / min, with a final pressure of 20MPa-80MPa. The holding time is 20min-120min. After the holding time is completed, the pressure is released directly, and the cooling rate is maintained at 50℃-200℃ / min. After cooling and demolding, a high-density molybdenum alloy sintered billet is obtained. Step 5: The molybdenum alloy sintered billet obtained in Step 4 is machined according to the dimensions in the drawing. Finally, the surface of the product is polished, cleaned, and dried to obtain the molybdenum alloy product (the molybdenum alloy product in this invention includes a molybdenum alloy plate and a molybdenum alloy target).

[0019] Step 5: Place the finished molybdenum alloy billet into a graphite mold of appropriate size, separating the contact surface with the mold with graphite paper to prevent sticking and facilitate demolding. Then, place the graphite mold in the sintering zone of the vacuum hot press furnace, adjusting the distance between the upper and lower pressure heads until they are just touching. Start the sintering program, first drawing a vacuum until the vacuum level reaches 10... -2 ~10 -3Heating begins at Pa, with the heating rate maintained at 10℃~80℃ / min. After 60min-180min, the temperature reaches 1400℃-1800℃, after which pressure is gradually applied at a rate of 2MPa-10MPa / min, with a final pressure of 20MPa-80MPa. The holding time is 20min-120min. After the holding time is completed, the pressure is released directly, and the cooling rate is maintained at 50℃-200℃ / min. After cooling and demolding, a high-density molybdenum alloy sintered billet is obtained. Step 6: The molybdenum alloy sintered billet obtained in Step 5 is machined according to the dimensions in the drawing. Finally, the surface of the product is polished, cleaned, and dried to obtain the molybdenum alloy product (the molybdenum alloy product in this invention includes a molybdenum alloy plate and a molybdenum alloy target).

[0020] Example 1 Step 1: Prepare 100 kg of molybdenum powder with a D50 of 23.507 μm as raw material A; prepare 100 kg of molybdenum powder with a D50 of 10.454 μm as raw material B; prepare 100 kg of molybdenum powder with a D50 of 4.442 μm as raw material C.

[0021] Step 2: Weigh 50kg of raw material A, 10kg of raw material B, and 40kg of raw material C respectively. Add raw material A, raw material B, and raw material C to a vacuum three-dimensional mixer in batches according to the mass percentages of 50%, 10%, and 40% respectively, and mix them under vacuum for 3 hours. Add 10kg of pure molybdenum balls, mix them, and then separate the spheres to obtain molybdenum pre-alloyed powder. Step 3: The molybdenum pre-alloyed powder obtained in Step 2 is loaded into a rubber sleeve with a diameter of 160mm and a loading amount of 33kg. After loading 10kg of material, the material is pressed 5 times. Then, the surface is smoothed and sealed. The material is pressed using a cold isostatic press at a pressure of 180MPa and a holding time of 8min to obtain a molybdenum alloy blank. Step 4: The molybdenum alloy blank is trimmed to a diameter of 119mm using a lathe, and then cut into a round plate blank with a thickness of 45mm using a band saw to obtain a finely trimmed molybdenum alloy plate blank. Step 5: Place the finished molybdenum alloy slab obtained in Step 4 into a 120mm diameter graphite mold, separating the contact surface with the mold with graphite paper to prevent sticking and facilitate demolding. Then, place the graphite mold in the sintering zone of a vacuum hot press furnace, adjusting the distance between the upper and lower pressure heads until they are just touching. Start the sintering program, first drawing a vacuum until the vacuum level reaches 10... -3Heating began at a rate of 20℃ / min. After 90 minutes, the temperature reached 1800℃. Pressure was then gradually applied at a rate of 5MPa / min, with a final pressure of 40MPa. The holding time was 120 minutes. After the holding time, the pressure was immediately released, and the cooling rate was maintained at 50℃-200℃ / min. After cooling and demolding, a high-density molybdenum alloy sintered billet with a diameter of 119mm × 37mm was obtained. Step 6: The molybdenum alloy sintered billet obtained in Step 5 is machined according to the dimensions in the drawing. Finally, the surface of the product is polished, cleaned, and dried to obtain a pure molybdenum metal circular target with a diameter of Φ115mm×33mm. The material utilization rate reaches 83.3%, which is a high standard for near-net forming material utilization in the same industry. Figure 1 This is a metallographic schematic diagram (×200) of a pure molybdenum plate obtained in Example 1 of the high-density molybdenum alloy product processing method of the present invention.

[0022] Example 2 Step 1: Prepare 100 kg of molybdenum powder with a D50 of 23.507 μm, designated as raw material A; prepare 100 kg of molybdenum powder with a D50 of 10.454 μm, designated as raw material B; prepare 100 kg of molybdenum powder with a D50 of 4.442 μm, designated as raw material C. Prepare 100 kg of high-purity rhenium powder with a D50 of 25.857 μm, designated as raw material D. Step 2: Weigh 15kg of raw material A, 14kg of raw material B, 68kg of raw material C, and 70kg of raw material D respectively. Add raw materials 1, 2, 3, and 4 to the three-dimensional mixer in batches according to the mass percentages of 10%, 10%, 40%, and 40%, respectively. Add 14kg of pure molybdenum balls. Argon gas is used for protection during mixing. The mixing time is 3 hours. After mixing, separate the spheres to obtain molybdenum pre-alloyed powder. Step 3: The molybdenum pre-alloyed powder obtained in Step 2 is loaded into a rubber sleeve with a diameter of 160mm and a loading amount of 33kg. After loading 10kg of material, the material is pressed 5 times. Then, the surface is smoothed and sealed. The material is pressed using a cold isostatic press at a pressure of 180MPa and a holding time of 8min to obtain a molybdenum alloy blank. Step 4: The molybdenum alloy blank obtained in Step 3 is trimmed to a diameter of 119mm using a lathe, and then cut into a round plate blank with a thickness of 45mm using a band saw to obtain a finely trimmed molybdenum alloy plate blank. Step 5: Place the finished molybdenum alloy slab obtained in Step 4 into a 120mm diameter graphite mold, separating the contact surface with the mold with graphite paper to prevent sticking and facilitate demolding. Then, place the graphite mold in the sintering zone of a vacuum hot press furnace, adjusting the distance between the upper and lower pressure heads until they are just touching. Start the sintering program, first drawing a vacuum until the vacuum level reaches 10... -3Heating began at a rate of 10℃ / min. After 170 minutes, the temperature reached 1700℃. Pressure was then gradually applied at a rate of 5MPa / min, with a final pressure of 60MPa. The holding time was 120 minutes. After holding, the pressure was released directly, and the cooling rate was maintained at 50℃-200℃ / min. After cooling and demolding, a high-density molybdenum alloy sintered billet with a diameter of 119mm × 32mm was obtained. Step 6: The molybdenum alloy sintered billet obtained in Step 5 is machined according to the dimensions in the drawing. Finally, the surface of the product is polished, cleaned, and dried to obtain a molybdenum-rhenium alloy round target with a diameter of Φ115mm×28mm and a rhenium content of 41%. The material utilization rate reaches 81.7%, which meets the high standard of near-net forming material utilization rate in the same industry.

[0023] Example 3 Step 1: Prepare 100 kg of molybdenum powder with a D50 of 23.507 μm (as raw material A); prepare 100 kg of molybdenum powder with a D50 of 10.454 μm (as raw material B); prepare 100 kg of molybdenum powder with a D50 of 4.442 μm (as raw material C). Prepare 1 kg of titanium hydride powder (through a 200-mesh sieve) (as raw material D); prepare 1 kg of zirconium hydride powder (through a 200-mesh sieve) (as raw material E); prepare 0.5 kg of graphite powder (through a 200-mesh sieve) (as raw material F). Step 2: Weigh 10kg of raw material C, 550g of raw material D, 120g of raw material E, and 40g of raw material F respectively. Add raw material C, raw material D, raw material E, and raw material F to the three-dimensional mixer in batches. Add 10kg of pure molybdenum balls. Argon gas is used for protection during mixing. The mixing time is 4 hours. After mixing, separate the ball material to obtain primary molybdenum pre-alloyed powder. Step 3: Weigh 50kg of raw material A, 10kg of raw material B, 30kg of raw material C, and primary molybdenum pre-alloyed powder respectively. Add raw material A, raw material B, raw material C, and primary molybdenum pre-alloyed powder to the three-dimensional mixer in batches. Add 10kg of pure molybdenum balls. Argon gas is used for protection during mixing. The mixing time is 4 hours. After mixing, separate the spheres to obtain molybdenum pre-alloyed powder. Step 4: The molybdenum pre-alloyed powder is loaded into a 460mm×330mm×40mm rubber sleeve, with a loading amount of 15kg, approximately 3kg at a time. After each loading, the sleeve is gently agitated and leveled. Finally, the sleeve is sealed with a shaping rubber stopper and a sealing rubber stopper, ensuring no gaps between the stopper and the powder to guarantee a smooth molding. Cold isostatic pressing is used, with the following process parameters: pressing pressure 180MPa, holding time 8min, to obtain the molybdenum alloy compact. Step 5: Trim the molybdenum alloy blank to 300mm×240mm×25mm using a lathe to obtain a finely trimmed molybdenum alloy slab blank. Step 6: Place the finished molybdenum alloy slab into a 301mm×241mm×26mm graphite mold. Separate all six surfaces in contact with the mold with graphite paper to prevent sticking and facilitate demolding. Then place the graphite mold in the sintering zone of a vacuum hot press furnace, adjusting the distance between the upper and lower pressure heads until they are just touching. Start the sintering program, first drawing a vacuum until the vacuum level reaches 10. -3 Heating began at a rate of 10℃ / min. After 185 minutes, the temperature reached 1850℃. Pressure was then gradually applied at a rate of 5MPa / min, with a final pressure of 70MPa. The holding time was 240 minutes. After the holding time, the pressure was immediately released, and the cooling rate was maintained at 50℃-200℃ / min. After cooling and demolding, a high-density molybdenum alloy sintered billet measuring 300mm × 168mm × 26mm was obtained. Step 7: The molybdenum alloy sintered billet is machined according to the dimensions in the drawing. Finally, the surface of the product is polished, cleaned, and dried to obtain a TZM (titanium (Ti)-zirconium (Zr)-molybdenum (Mo) series alloy) molybdenum alloy plate with dimensions of 296mm×164mm×22mm. The material utilization rate reaches 81.5%, which meets the high standard of net near-forming material utilization rate in the same industry. Figure 2 This is a schematic diagram of the metallographic structure of the TZM plate obtained in Example 3 of the high-density molybdenum alloy product processing method of the present invention; Example 4 Step 1: Prepare 100 kg of molybdenum powder with a D50 of 23.507 μm, designated as raw material A; prepare 100 kg of molybdenum powder with a D50 of 10.454 μm, designated as raw material B; prepare 100 kg of molybdenum powder with a D50 of 4.442 μm, designated as raw material C; prepare 20 kg of high-purity tantalum powder with a D50 of 4.655 μm, designated as raw material D. Step 2: Weigh 50kg of raw material A, 10kg of raw material B, 40kg of raw material C, and 17.6kg of raw material D respectively. Add raw material A, raw material B, raw material C, and raw material D to the three-dimensional mixer in batches according to the mass percentages of 50%, 10%, 34%, and 6%. Add 15kg of pure molybdenum balls. Argon gas is used for protection during mixing. The mixing time is 4 hours. After mixing, separate the spheres to obtain molybdenum pre-alloyed powder. Step 3: The molybdenum pre-alloyed powder is loaded into a rubber sleeve with a diameter of 160mm and the loading amount is 33kg. After loading 10kg of material, the material is pressed five times. Then the surface is smoothed and sealed. The material is pressed using a cold isostatic press at a pressure of 180MPa and a holding time of 8min to obtain the molybdenum alloy blank. Step 4: The molybdenum alloy blank is trimmed to a diameter of 119mm using a lathe, and then cut into a round plate blank with a thickness of 45mm using a band saw to obtain a finely trimmed molybdenum alloy plate blank. Step 5: Place the finished molybdenum alloy slab into a 120mm diameter graphite mold, separating the contact surface with the mold with graphite paper to prevent sticking and facilitate demolding. Then, place the graphite mold in the sintering zone of the vacuum hot press furnace, adjusting the distance between the upper and lower pressure heads until they are just touching. Start the sintering program, first drawing a vacuum until the vacuum level reaches 10... -3 Heating began at a rate of 10℃ / min. After 185 minutes, the temperature reached 1850℃. Pressure was then gradually applied at a rate of 5MPa / min, with a final pressure of 70MPa. The holding time was 120 minutes. After the holding time, the pressure was immediately released, and the cooling rate was maintained at 50℃-200℃ / min. After cooling and demolding, a high-density molybdenum alloy sintered billet with a diameter of 119mm × 35mm was obtained. Step 6: The molybdenum alloy sintered billet is machined according to the dimensions in the drawing. Finally, the surface of the product is polished, cleaned, and dried to obtain a molybdenum-tantalum alloy round target with a diameter of Φ115mm × 30mm and a tantalum content of 15%. The material utilization rate reaches 80%, achieving a high standard of near-net forming material utilization in the industry. Figure 3 This is a schematic diagram of the metallographic structure of the molybdenum-tantalum plate obtained in Example 4 of the high-density molybdenum alloy product processing method of the present invention.

[0024] Example 5 Step 1: Prepare 100 kg of molybdenum powder with a D50 of 23.507 μm, designated as raw material A; prepare 100 kg of molybdenum powder with a D50 of 4.442 μm, designated as raw material B; prepare 20 kg of high-purity niobium powder with a D50 of 11.855 μm, designated as raw material C; Step 2: Weigh 50kg of raw material A, 40kg of raw material B, and 10kg of raw material C respectively. Add raw material A, raw material B, and raw material C to the three-dimensional mixer in batches according to the mass percentages of 50%, 40%, and 10%, respectively. Add 10kg of pure molybdenum balls. Argon gas is used for protection during mixing. The mixing time is 4 hours. After mixing, separate the spheres to obtain molybdenum pre-alloyed powder. Step 3: The molybdenum pre-alloyed powder is loaded into a rubber sleeve with a diameter of 160 mm. A stainless steel core mold with a diameter of 130 mm is installed in the center of the rubber sleeve. The loading amount is 33 kg. After loading 10 kg of material, the material is pressed five times. Then it is leveled, and a ring rubber stopper is used to press it on the stainless steel core mold. Then a solid rubber stopper is used to seal it. The material is pressed using a cold isostatic press at a pressure of 180 MPa and a holding time of 8 min to obtain a molybdenum alloy tubular compact. Step 4: Trim the molybdenum alloy tube blank to an outer diameter of 160 mm and keep the inner diameter at 130 mm using a lathe, and cut it into round tube blanks with a length of 350 mm to obtain a finely trimmed molybdenum alloy tube blank. Step 5: Place the finished molybdenum alloy slab into a 160mm diameter annular graphite mold. The core mold has a diameter of 129mm. Separate the contact surfaces with the core mold using graphite paper to prevent adhesion and facilitate demolding. Then, place the graphite mold in the sintering zone of a vacuum hot press furnace, adjusting the distance between the upper and lower pressure heads until they are just touching. Start the sintering program, first drawing a vacuum until the vacuum level reaches 10... -3 Heating began at a rate of 10℃ / min. After 160 minutes, the temperature reached 1600℃. Pressure was then gradually applied at a rate of 5MPa / min, with a final pressure of 60MPa. The holding time was 150 minutes. After holding, the pressure was released directly, and the cooling rate was maintained at 50℃-200℃ / min. After cooling and demolding, a high-density molybdenum alloy tubular sintered billet with an outer diameter of 160mm, an inner diameter of 130mm, and a height of 298mm was obtained. Step 6: The molybdenum alloy sintered billet is machined according to the dimensions in the drawings. Finally, the surface of the product is polished, cleaned, and dried to obtain a molybdenum-niobium alloy tube target with an outer diameter of 150mm, an inner diameter of 135mm, a height of 295mm, and a niobium content of 10%. The material utilization rate reaches 49%, which is a high standard for net near-forming material utilization rate of similar products in the same industry. Figure 4 This is a schematic diagram of the metallographic structure of the molybdenum-niobium plate obtained in Example 5 of the high-density molybdenum alloy product processing method of the present invention.

[0025] Example 6 Compared with Example 1, in step 2, vacuum mixing is performed in a vacuum three-dimensional mixer for 1 hour, and the remaining steps are the same as in Example 1.

[0026] Example 7 Compared with Example 1, in step 2, vacuum mixing is carried out in a vacuum three-dimensional mixer for 4 hours, and the remaining steps are the same as in Example 1.

[0027] The high-density molybdenum alloy product processing method provided by this invention first involves grading and distributing the original powder to increase its filling density. The graded molybdenum alloy powder is then loaded into a near-net-shape forming mold, and a blank is formed using cold isostatic pressing. After cutting to the finished product dimensions, it is formed in one step using a vacuum high-temperature molding method. The resulting molybdenum and its alloy products have regular shapes, high density, and require less processing. This not only reduces processing steps and saves processing costs but also shortens the processing cycle and improves material utilization (high temperature and high pressure result in high density; traditional sintering requires pressure processing, such as forging and rolling).

Claims

1. A method for processing high-density molybdenum alloy products, characterized in that: Specifically, the steps include the following: Step 1: Select molybdenum powder raw materials; Step 2: Mix the raw materials selected in Step 1, and then separate the spherical material to obtain molybdenum pre-alloyed powder; Step 3: The molybdenum pre-alloyed powder obtained in Step 2 is loaded into a rubber sleeve for processing to obtain a molybdenum alloy finished billet; Step 4: Place the finished molybdenum alloy billet into a mold for sintering to obtain a sintered molybdenum alloy billet. Step 5: Polish the molybdenum alloy obtained in Step 4, clean and dry it to obtain the molybdenum alloy product.

2. The method for processing high-density molybdenum alloy products according to claim 1, characterized in that: The specific process of step 1 is as follows: when the raw material is pure molybdenum powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; and the molybdenum powder with a particle size distribution D50 of 5~8μm is identified as raw material C. The specific process of step 2 is as follows: raw materials A, B and C are mixed and used as the grading raw materials for molybdenum powder. They are added to a vacuum three-dimensional mixer and mixed in a vacuum or argon atmosphere for 1 to 4 hours. At the same time, pure molybdenum balls are added at a ball-to-material mass ratio of 1:10 to 20. After mixing, the balls are separated to obtain molybdenum pre-alloyed powder.

3. The method for processing high-density molybdenum alloy products according to claim 1, characterized in that: The specific process of step 1 is as follows: when the raw material is a molybdenum-rhenium mixed powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; the molybdenum powder with a particle size distribution D50 of 5~8μm is identified as raw material C; and the pure rhenium powder with a particle size distribution D50 of 20~30μm is identified as raw material D. The specific process of step 2 is as follows: raw materials A, B, C and D are mixed and used as the grading raw materials for molybdenum powder. They are added to a vacuum three-dimensional mixer and mixed in a vacuum or argon atmosphere for 1 to 4 hours. At the same time, pure molybdenum balls are added at a ball-to-material mass ratio of 1:10 to 20. After mixing, the balls are separated to obtain molybdenum pre-alloyed powder.

4. The method for processing high-density molybdenum alloy products according to claim 1, characterized in that: The specific process of step 1 is as follows: when the raw material is TZM mixed powder, molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; molybdenum powder with a particle size distribution D50 of 5~8μm is identified as raw material C; titanium hydride powder is identified as raw material D; zirconium hydride powder is identified as raw material E; and graphite powder is identified as raw material F. The specific process of step 2 is as follows: Step 2.1: Weigh raw materials C, D, E and F respectively, add raw materials C, D, E and F into a three-dimensional mixer, and mix under vacuum or argon atmosphere for 1-4 hours. At the same time, add pure molybdenum balls at a ball-to-material mass ratio of 1:10-20. After mixing, separate the ball-to-material to obtain primary molybdenum pre-alloyed powder A. Step 2.2: Weigh raw material A, raw material B, raw material C, and primary molybdenum pre-alloyed powder respectively. Add raw material A, raw material B, raw material C, and primary molybdenum pre-alloyed powder to a three-dimensional mixer and mix under vacuum or argon atmosphere for 1-4 hours. At the same time, add pure molybdenum balls at a ball-to-material mass ratio of 1:10-20. After mixing, separate the balls to obtain molybdenum pre-alloyed powder.

5. The method for processing high-density molybdenum alloy products according to claim 1, characterized in that: The specific process of step 1 is as follows: when the raw material is a molybdenum-niobium mixed powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; and the pure niobium powder with a particle size distribution D50 of 10~15μm is identified as raw material C. The specific process of step 2 is as follows: Raw materials A, B, and C are mixed and used as the grading raw materials for molybdenum powder. They are then added to a vacuum three-dimensional mixer and mixed under vacuum or argon atmosphere for 1-4 hours. At the same time, pure molybdenum balls are added at a ball-to-material mass ratio of 1:10-20. After mixing, the balls are separated to obtain molybdenum pre-alloyed powder.

6. The method for processing high-density molybdenum alloy products according to claim 1, characterized in that: The specific process of step 1 is as follows: when the raw material is a molybdenum-tantalum mixed powder, the molybdenum powder with a particle size distribution D50 of 20~30μm is identified as raw material A; the molybdenum powder with a particle size distribution D50 of 10~15μm is identified as raw material B; the molybdenum powder with a particle size distribution D50 of 5~8μm is identified as raw material C; and the pure tantalum with a particle size distribution D50 of 5~8μm is identified as raw material D. The specific process of step 2 is as follows: Raw materials A, B, C and D are mixed and used as the grading raw materials for molybdenum powder. They are then added to a vacuum three-dimensional mixer and mixed under vacuum or argon atmosphere for 1 to 4 hours. At the same time, pure molybdenum balls are added at a ball-to-material mass ratio of 1:10 to 20. After mixing, the balls are separated to obtain molybdenum pre-alloyed powder.

7. The method for processing high-density molybdenum alloy products according to claim 1, characterized in that: The specific process of step 1 is as follows: The specific process of step 3 is as follows: The molybdenum pre-alloyed powder obtained in step 2 is loaded into a rubber sleeve, sealed, and then pressed using a cold isostatic press at a pressure of 150MPa~200MPa and a holding time of 5min~10min to obtain a molybdenum alloy blank. The obtained molybdenum alloy blank is then cut to obtain a molybdenum alloy precision blank.

8. The method for processing high-density molybdenum alloy products according to claim 1, characterized in that: The specific process of step 1 is as follows: The specific process of step 4 is as follows: Place the molybdenum alloy precision-finished billet into a graphite mold of the corresponding size, then place the graphite mold in the sintering zone of the vacuum hot press furnace, adjust the distance between the upper and lower pressure heads until they just touch, start the sintering program, and obtain the molybdenum alloy sintered billet.

9. The method for processing high-density molybdenum alloy products according to claim 8, characterized in that: The specific process of step 1 is as follows: In step 4, the specific process of sintering is as follows: First, a vacuum is drawn until the vacuum degree reaches 10. -2 ~10 -3 The temperature is raised starting at Pa, with the heating rate maintained at 10℃ / min to 80℃ / min. After 60min to 180min, the temperature reaches 1400℃ to 1800℃. Then, pressure is gradually applied, with the pressurization rate controlled at 2MPa to 10MPa / min, and the final pressure is 20MPa to 80MPa. The holding time is 20min to 120min. After the holding time is completed, the pressure is released directly, and the cooling rate is maintained at 50℃ / min to 200℃ / min. After cooling, the molybdenum alloy sintered billet is obtained after demolding.

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