A method for preparing tungsten alloys with different components or different forming processes by sintering in the same furnace

Abstract

The present invention provides a method for preparing tungsten alloys with different components or different molding processes by sintering in the same furnace, and belongs to the technical field of powder metallurgy. According to the characteristics that the higher the tungsten content in the tungsten alloy, the higher the sintering temperature, and the characteristics that the molded compact will be activated during the degumming process so that the required sintering temperature is low, while the cold isostatic pressed compact is directly sintered so that the required sintering temperature is high, the present invention sinters the compacts obtained with different tungsten contents or different molding processes by buried burning, 1 / 2 buried burning or bare burning, etc. During bare burning, the compact is directly in contact with the environment and is subjected to a higher temperature, while during buried burning or 1 / 2 buried burning, the compact is subjected to a lower temperature during the same furnace sintering process, so that the compacts obtained with different tungsten contents or different molding processes during the same furnace sintering process are subjected to different sintering temperatures, so that the compacts obtained with different tungsten contents or different molding processes can be sintered in the same furnace, and the obtained tungsten alloy is guaranteed to have good mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of powder metallurgy, and in particular to a method for preparing tungsten alloys with different components or different molding processes by sintering in the same furnace. Background Art

[0002] Tungsten alloy consists of a tungsten phase with a high melting point and a γ phase (Ni-Cu, Ni-Fe) with a lower melting point. The melting points of the two phases are very different (the melting point of the tungsten phase is 3410℃, and the melting point of the γ phase is lower). Tungsten alloy is usually sintered in liquid phase. During the sintering process, the sintering temperature and holding time must be strictly controlled. According to the equilibrium phase diagram of W-Ni-Fe alloy, if the tungsten content in the alloy is high, the sintering temperature should be increased. On the contrary, when the tungsten content is reduced, the sintering temperature should be reduced. In the conventional sintering production of tungsten alloy, the sintering temperature of 90WNiFe alloy is 1420℃, and the holding time is 35min. The sintering temperature of 93WNiFe alloy is 1465℃, and the holding time is 45min. The sintering temperature of 95WNiFe alloy is 1510℃, and the holding time is 60min. The sintering temperature of 97WNiFe alloy is 1580℃, and the holding time is 70min. Since the sintering temperature and sintering holding time of different tungsten alloys are different, when preparing tungsten alloys, it is necessary to adjust the sintering temperature and holding time after one component of tungsten alloy is out of the furnace to prepare the next tungsten alloy. Frequent adjustment of sintering temperature and holding time leads to a longer production cycle of tungsten alloys, low equipment utilization, serious energy waste, and a substantial increase in production costs, which seriously restricts the development of the industry.

[0003] Therefore, how to achieve the synchronous production of tungsten alloys with different tungsten contents or different forming processes has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing tungsten alloys with different components or different forming processes by sintering in the same furnace. The preparation method provided by the present invention can synchronously produce tungsten alloys with different components and different forming processes without affecting their mechanical properties.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing tungsten alloys with different components or different forming processes by sintering in the same furnace, comprising the following steps:

[0007] (1) mixing the raw materials to obtain a mixed powder;

[0008] (2) subjecting the mixed powder obtained in step (1) to granulation, compression molding and activation treatment in sequence to obtain an activated compression molded compact;

[0009] and / or, subjecting the mixed powder obtained in step (1) to cold isostatic pressing to obtain a cold isostatic pressed green compact;

[0010] (3) When the green compact is the activated molded green compact obtained in step (2), the activated molded green compact with low tungsten content is completely buried and the activated molded green compact with high tungsten content is sintered in the same furnace to obtain a tungsten alloy material.

[0011] Alternatively, when the pressed green sheet is the cold isostatic pressed green sheet obtained in step (2), the cold isostatic pressed green sheet with low tungsten content is completely buried and fired, and the cold isostatic pressed green sheet with high tungsten content is 1 / 2 buried or bare fired, and sintered in the same furnace to obtain the tungsten alloy material;

[0012] Alternatively, when the pressed green sheet is the activated mold pressed green sheet and the cold isostatic pressed green sheet obtained in step (2), the activated mold pressed green sheet is completely buried and the cold isostatic pressed green sheet is 1 / 2 buried or bare, and the tungsten alloy material is sintered in the same furnace;

[0013] (4) Annealing the tungsten alloy material obtained in step (3) to obtain a tungsten alloy.

[0014] Preferably, the raw materials in step (1) include tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder; the tungsten powder has a Fischer-Strauss particle size of 2.5-3.5 μm, the nickel powder has a Fischer-Strauss particle size of 2.5-3.5 μm, the iron powder has a Fischer-Strauss particle size of 5-8 μm, the cobalt powder has a Fischer-Strauss particle size of 1-2.5 μm, and the manganese powder has a Fischer-Strauss particle size of 6-8.5 μm.

[0015] Preferably, the mass ratio of the tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder is (85-97): (1.5-10): (0.5-5): (0.1-0.6): (0.05-0.15).

[0016] Preferably, in step (2), the compression molding pressure is 10-30 MPa, and the holding time of the compression molding is 10-30 s.

[0017] Preferably, the holding temperature of the activation treatment in step (2) is 600-800° C., and the holding time of the activation treatment is 24-36 hours.

[0018] Preferably, in step (2), the pressing pressure of the cold isostatic pressing is 120-240 MPa, and the holding time of the cold isostatic pressing is 60-240 s.

[0019] Preferably, the medium used in the complete burial method or the 1 / 2 burial method in step (3) is alumina sand.

[0020] Preferably, in the step (3), the atmosphere for sintering in the same furnace is hydrogen, the sintering temperature for sintering in the same furnace is 1350-1560° C., and the holding time for sintering in the same furnace is 30-60 min.

[0021] Preferably, the vacuum degree of the annealing treatment in step (4) is less than 1.33×10 -2 Pa, the holding temperature of annealing treatment is 1000~1200℃, and the holding time of annealing treatment is 1~3h.

[0022] Preferably, in step (4), the chemical composition of the tungsten alloy comprises, by mass percentage, tungsten: 85-97%, nickel: 1.5-10%, iron: 0.5-5%, Co: 0.1-0.6% and manganese: 0.05-0.15%.

[0023] The present invention provides a method for preparing tungsten alloys with different components or different molding processes by sintering in the same furnace, comprising the following steps: (1) mixing raw materials to obtain mixed powder; (2) sequentially granulating, compression molding and activating the mixed powder obtained in step (1) to obtain an activated molded compact; and / or, cold isostatic pressing the mixed powder obtained in step (1) to obtain a cold isostatic pressing compact; (3) when the compact is the activated molded compact obtained in step (2), the activated molded compact with low tungsten content is completely buried and the activated molded compact with high tungsten content is 1 / 2 buried or bare, and the mixture is granulated, compression molded and activated to obtain an activated molded compact; and the mixture is granulated, compression molded and activated to obtain an activated molded compact. or, when the pressed blank is the cold isostatic pressed blank obtained in step (2), the cold isostatic pressed blank with low tungsten content is completely buried and the cold isostatic pressed blank with high tungsten content is sintered in the same furnace to obtain the tungsten alloy material; or, when the pressed blank is the activated molded pressed blank and the cold isostatic pressed blank obtained in step (2), the activated molded pressed blank is completely buried and the cold isostatic pressed blank is sintered in the same furnace to obtain the tungsten alloy material; (4) the tungsten alloy material obtained in step (3) is annealed to obtain the tungsten alloy. According to the characteristics that the higher the tungsten content in the tungsten alloy, the higher the sintering temperature, and the characteristics that the molded compact will be activated during the degumming process so that the required sintering temperature is low, while the cold isostatic pressed compact is directly sintered so that the required sintering temperature is high, the present invention performs different sintering methods such as buried burning, 1 / 2 buried burning or bare burning for compacts obtained with different tungsten contents or different molding processes. During bare burning, the compact is directly in contact with the environment and is subjected to a higher temperature, while during buried burning or 1 / 2 buried burning, under the action of sand, the compact is subjected to a lower temperature during the same furnace sintering process, so that the compacts obtained with different tungsten contents or different molding processes in the same furnace sintering process are subjected to different sintering temperatures, so that the compacts obtained with different tungsten contents or different molding processes can be sintered in the same furnace, and the obtained tungsten alloy has good mechanical properties. At the same time, the temperature reduced by the complete buried burning method and the 1 / 2 buried burning method provided by the present invention is different, so different sintering methods can be selected according to the tungsten content and molding process, thereby improving the applicability of the same furnace sintering process, which is conducive to its large-scale promotion in tungsten alloy production. The results of the examples show that, for tungsten alloys prepared by the same furnace sintering process provided by the present invention, when the tungsten content in the tungsten alloys is the same, the density and mechanical properties of the tungsten alloys are relatively small and within the error range, while the properties of tungsten alloys with different contents are significantly different, indicating that the method of the present invention can prepare tungsten alloys of different types without affecting their performance.

[0024] The tungsten alloy same-furnace sintering process provided by the present invention solves the problems of long product production cycle and low equipment utilization rate caused by frequent adjustment of sintering temperature during the production process of tungsten alloy materials with different tungsten contents or different forming processes, thereby reducing production costs, improving production efficiency, and greatly improving enterprise benefits. DETAILED DESCRIPTION

[0025] The present invention provides a method for preparing tungsten alloys with different components or different forming processes by sintering in the same furnace, comprising the following steps:

[0026] (1) mixing the raw materials to obtain a mixed powder;

[0027] (2) subjecting the mixed powder obtained in step (1) to granulation, compression molding and activation treatment in sequence to obtain an activated compression molded compact;

[0028] and / or, subjecting the mixed powder obtained in step (1) to cold isostatic pressing to obtain a cold isostatic pressed green compact;

[0029] (3) When the green compact is the activated molded green compact obtained in step (2), the activated molded green compact with low tungsten content is completely buried and the activated molded green compact with high tungsten content is sintered in the same furnace to obtain a tungsten alloy material.

[0030] Alternatively, when the pressed green sheet is the cold isostatic pressed green sheet obtained in step (2), the cold isostatic pressed green sheet with low tungsten content is completely buried and fired, and the cold isostatic pressed green sheet with high tungsten content is 1 / 2 buried or bare fired, and sintered in the same furnace to obtain the tungsten alloy material;

[0031] Alternatively, when the pressed green sheet is the activated mold pressed green sheet and the cold isostatic pressed green sheet obtained in step (2), the activated mold pressed green sheet is completely buried and the cold isostatic pressed green sheet is 1 / 2 buried or bare, and the tungsten alloy material is sintered in the same furnace;

[0032] (4) Annealing the tungsten alloy material obtained in step (3) to obtain a tungsten alloy.

[0033] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art.

[0034] The invention mixes raw materials to obtain mixed powder.

[0035] In the present invention, the raw materials preferably include tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder.

[0036] In the present invention, the Fischer-Strauss particle size of the tungsten powder is preferably 2.5-3.5 μm, more preferably 3 μm; the Fischer-Strauss particle size of the nickel powder is preferably 2.5-3.5 μm, more preferably 3 μm; the Fischer-Strauss particle size of the iron powder is preferably 5-8 μm, more preferably 6-7 μm; the Fischer-Strauss particle size of the cobalt powder is preferably 1-2.5 μm, more preferably 1.5-2 μm; the Fischer-Strauss particle size of the manganese powder is preferably 6-8.5 μm, more preferably 7-8 μm. The present invention can control the particle size of the powder to make it more evenly mixed and improve the density of the tungsten alloy during the sintering process.

[0037] The present invention has no special limitation on the usage relationship of the tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder, and the usage relationship can be controlled according to the composition of the tungsten alloy to be prepared.

[0038] In the present invention, the mass ratio of tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder is preferably (85-97): (1.5-10): (0.5-5): (0.1-0.6): (0.05-0.15), more preferably (87-95): (2-8): (1-4): (0.2-0.5): (0.08-0.12), and further preferably (90-93): (5-6): (3-4): (0.3-0.4): 0.1. The present invention can ensure that the chemical composition of the tungsten alloy meets the requirements by controlling the amount of each component.

[0039] In the present invention, the mixing method is preferably ball milling; the ball-to-material ratio of the ball milling is preferably (1-2):1; and the ball milling time is preferably 10-24 hours. The present invention can make the raw materials mixed more uniformly by adopting the ball milling mixing method.

[0040] As an embodiment of the present invention, the ball milling mixing time can be 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h or 24 h.

[0041] After obtaining the mixed powder, the present invention sequentially performs granulation, compression molding and activation treatment on the mixed powder to obtain an activated compression compact.

[0042] The present invention has no particular limitation on the specific operation of the granulation, and a granulation method well known to those skilled in the art can be used to make the particle size of the particles meet the requirements. As an embodiment of the present invention, the particle size of the granulation can be 40 to 120 mesh, and can also be 40 mesh, 50 mesh, 60 mesh, 70 mesh, 80 mesh, 90 mesh, 100 mesh, 110 mesh or 120 mesh.

[0043] In the present invention, the compression pressure of the compression molding is preferably 10-30 MPa; the holding time of the compression molding is preferably 10-30 s. The present invention can improve the compactness of the compression molding blank by controlling the compression molding parameters, laying a foundation for the subsequent preparation of tungsten alloy.

[0044] As an embodiment of the present invention, the pressing pressure of the compression molding may be 10 MPa, 15 MPa, 20 MPa, 25 MPa or 30 MPa; the holding time of the compression molding may be 10 s, 15 s, 20 s, 25 s or 30 s.

[0045] In the present invention, the holding temperature of the activation treatment is preferably 600-800° C.; the holding time of the activation treatment is preferably 24-36 hours.

[0046] As an embodiment of the present invention, the holding temperature of the activation treatment can be 600°C, 650°C, 700°C, 750°C or 800°C; the holding time of the activation treatment can be 24h, 26h, 28h, 30h, 32h, 34h or 36h.

[0047] After obtaining the mixed powder, the present invention performs cold isostatic pressing on the mixed powder to obtain a cold isostatic pressed green compact.

[0048] In the present invention, the pressing pressure of the cold isostatic pressing is preferably 120-240 MPa; the holding time of the cold isostatic pressing is preferably 60-240 s. The present invention can improve the density of the cold isostatic pressing blank by controlling the parameters of the cold isostatic pressing, laying a foundation for the subsequent preparation of tungsten alloy.

[0049] As an embodiment of the present invention, the pressing pressure of the cold isostatic pressing can be 120MPa, 140MPa, 160MPa, 180MPa, 200MPa, 220MPa or 240MPa; the holding time of the cold isostatic pressing can be 60s, 80s, 100s, 120s, 140s, 160s, 180s, 200s, 220s or 240s.

[0050] After obtaining the activated molded compact, when the compact is the activated molded compact, the present invention uses a complete burying method for the activated molded compact with a low tungsten content, and a 1 / 2 burying method or a bare burying method for the activated molded compact with a high tungsten content, and sintering them in the same furnace to obtain a tungsten alloy material.

[0051] In the present invention, when the tungsten contents in the activated molded green compact are different, the difference in tungsten content between the activated molded green compact with low tungsten content and the activated molded green compact with high tungsten content is preferably 2-3wt.%. By controlling the difference in tungsten content, the present invention can avoid the situation where the high tungsten alloy is under-burned after sintering in the same furnace due to a large difference, and can also avoid the situation where the low tungsten alloy is over-burned after sintering in the same furnace due to a small difference.

[0052] In the present invention, the medium used in the complete burial method or the 1 / 2 burial method is preferably alumina sand. The present invention has no special limitation on the specific source of the alumina sand, and commercially available alumina sand well known to those skilled in the art can be used. In the present invention, the thickness of the alumina sand in the complete burial method is preferably ≥10mm, more preferably 10~20mm, and further preferably 12~15mm. In the present invention, the thickness of the alumina sand in the 1 / 2 burial method is preferably ≥10mm, more preferably 10~20mm, and further preferably 12~15mm. The present invention has no special limitation on the specific operation of the 1 / 2 burial method, and the 1 / 2 burial method well known to those skilled in the art can be used. The present invention uses alumina sand as the burial medium to avoid the reaction between the medium and the surface of the pressed green sheet during the sintering process; by controlling the thickness of the alumina sand, the sintering temperature can be well reduced.

[0053] In the present invention, the sintering in the same furnace is preferably performed in a push rod type automatic sintering furnace. The present invention has no special limitation on the specific model of the push rod type automatic sintering furnace, and a commercially available push rod type automatic sintering furnace well known to those skilled in the art can be used.

[0054] In the present invention, the atmosphere of the sintering in the same furnace is preferably hydrogen; the hydrogen is preferably hydrogen prepared by ammonia decomposition; the sintering temperature of the sintering in the same furnace is preferably 1350-1560°C; the holding time of the sintering in the same furnace is preferably 30-60 minutes. The present invention can ensure that a tungsten alloy material with a dense structure and excellent mechanical properties is obtained by controlling the process parameters of the sintering in the same furnace.

[0055] As an embodiment of the present invention, the sintering temperature of the same-furnace sintering can be 1350°C, 1400°C, 1450°C, 1500°C, 1550°C or 1560°C; the holding time of the same-furnace sintering can be 30min, 35min, 40min, 45min, 50min, 55min or 60min.

[0056] After obtaining the cold isostatic pressed billet, when the billet is the cold isostatic pressed billet, the present invention adopts a complete burying method for the cold isostatic pressed billet with low tungsten content and a 1 / 2 burying method or a bare burying method for the cold isostatic pressed billet with high tungsten content, and sintering them in the same furnace to obtain a tungsten alloy material.

[0057] In the present invention, when the tungsten contents in the cold isostatic pressed billets are different, the difference in tungsten content between the cold isostatic pressed billets with low tungsten content and the cold isostatic pressed billets with high tungsten content is preferably 2-3wt.%. By controlling the difference in tungsten content, the present invention can avoid the situation where the high tungsten alloy is under-burned after sintering in the same furnace due to a large difference, and can also avoid the situation where the low tungsten alloy is over-burned after sintering in the same furnace due to a small difference.

[0058] In the present invention, the medium and thickness used in the complete burial method and the 1 / 2 burial method are preferably the same as those mentioned above, and will not be repeated here.

[0059] In the present invention, the equipment used for the same-furnace sintering and the process parameters for the same-furnace sintering are preferably the same as those of the above-mentioned same-furnace sintering, and will not be described in detail here.

[0060] After obtaining the activated molded blank and the cold isostatic pressed blank, when the blanks are the activated molded blank and the cold isostatic pressed blank, the present invention adopts a complete buried burning method for the activated molded blank and a 1 / 2 buried burning method or a bare burning method for the cold isostatic pressed blank, and sintering them in the same furnace to obtain the tungsten alloy material.

[0061] In the present invention, when the activated molded green compact and the cold isostatic pressed green compact are used, the tungsten content in the activated molded green compact and the cold isostatic pressed green compact is preferably the same. By controlling the above conditions, the present invention can avoid the undesirable conditions such as under-burning or over-burning of green compacts prepared by different processes during sintering in the same furnace.

[0062] In the present invention, the medium and thickness used in the complete burial method and the 1 / 2 burial method are preferably the same as those mentioned above, and will not be repeated here.

[0063] In the present invention, the equipment used for the same-furnace sintering and the process parameters for the same-furnace sintering are preferably the same as those of the above-mentioned same-furnace sintering, and will not be described in detail here.

[0064] After obtaining the tungsten alloy material, the present invention performs annealing treatment on the tungsten alloy material to obtain the tungsten alloy.

[0065] In the present invention, the annealing treatment is preferably carried out in a vacuum furnace. The present invention has no particular limitation on the specific model of the vacuum furnace, and a commercially available vacuum furnace well known to those skilled in the art can be used as long as the annealing treatment temperature meets the requirements.

[0066] In the present invention, the vacuum degree of the annealing treatment is preferably less than 1.33×10 -2Pa; the holding temperature of the annealing treatment is preferably 1000-1200°C; the holding time of the annealing treatment is preferably 1-3h. The present invention can optimize the microstructure of the tungsten alloy material and improve the toughness and ductility of the tungsten alloy by annealing the tungsten alloy material.

[0067] As an embodiment of the present invention, the holding temperature of the annealing treatment may be 1000°C, 1050°C, 1100°C, 1150°C or 1200°C; the holding time of the annealing treatment may be 1h, 1.5h, 2h, 2.5h or 3h.

[0068] In the present invention, the chemical composition of the tungsten alloy preferably includes, by mass percentage, tungsten: 85-97%, nickel: 1.5-10%, iron: 0.5-5%, Co: 0.1-0.6% and manganese: 0.05-0.15%. The present invention can prepare a tungsten alloy with excellent performance by controlling the chemical composition and dosage of the tungsten alloy.

[0069] As an embodiment of the present invention, the chemical composition of the tungsten alloy, measured by mass percentage, can be: tungsten: 87-95%, nickel: 2-8%, iron: 1-4%, Co: 0.2-0.5% and manganese: 0.08-0.12%, or can be: tungsten: 90-93%, nickel: 5-6%, iron: 3-4%, Co: 0.3-0.4% and manganese: 0.1%.

[0070] According to the characteristics that the higher the tungsten content in the tungsten alloy, the higher the sintering temperature, and the characteristics that the molded compact will be activated during the degumming process so that the required sintering temperature is low, while the cold isostatic pressed compact is directly sintered so that the required sintering temperature is high, the present invention performs different sintering methods such as buried burning, 1 / 2 buried burning or bare burning for compacts obtained with different tungsten contents or different molding processes. During bare burning, the compact is directly in contact with the environment and is subjected to a higher temperature, while during buried burning or 1 / 2 buried burning, under the action of sand, the compact is subjected to a lower temperature during the same furnace sintering process, so that the compacts obtained with different tungsten contents or different molding processes in the same furnace sintering process are subjected to different sintering temperatures, so that the compacts obtained with different tungsten contents or different molding processes can be sintered in the same furnace, and the obtained tungsten alloy has good mechanical properties. At the same time, the temperature reduced by the complete buried burning method and the 1 / 2 buried burning method provided by the present invention is different, so different sintering methods can be selected according to the tungsten content and molding process, thereby improving the applicability of the same furnace sintering process, which is conducive to its large-scale promotion in tungsten alloy production.

[0071] The tungsten alloy same-furnace sintering process provided by the present invention solves the problems of long product production cycle and low equipment utilization rate caused by frequent adjustment of sintering temperature during the production process of tungsten alloy materials with different tungsten contents or different forming processes, thereby reducing production costs, improving production efficiency, and greatly improving enterprise benefits.

[0072] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0073] Example 1

[0074] A method for preparing tungsten alloys with different compositions or different forming processes by sintering in the same furnace is as follows:

[0075] (1) Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 90:6.4:3.2:0.35:0.05 and then ball-milled to obtain 90WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 2.5 μm, the nickel powder has a Fischer-Strauss particle size of 3 μm, the iron powder has a Fischer-Strauss particle size of 6 μm, the cobalt powder has a Fischer-Strauss particle size of 1.5 μm, and the manganese powder has a Fischer-Strauss particle size of 7 μm; the ball-to-material ratio of the ball-milling mixture is 2:1, and the ball-milling mixing time is 15 h;

[0076] Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 93:4.4:2.2:0.3:0.1 and then ball-milled to obtain 93WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3.5 μm, the nickel powder has a Fischer-Strauss particle size of 3 μm, the iron powder has a Fischer-Strauss particle size of 6 μm, the cobalt powder has a Fischer-Strauss particle size of 1 μm, and the manganese powder has a Fischer-Strauss particle size of 6.5 μm; the ball-to-material ratio of the ball-milling mixture is 1:1, and the ball-milling mixing time is 12 h;

[0077] (2) The 90WNiFe mixed powder and the 93WNiFe mixed powder obtained in the step (1) are granulated, compression molded and activated respectively to obtain 90WNiFe activated compression molded green sheets and 93WNiFe activated compression molded green sheets; the particle size of the granulation is independently 40-120 mesh; the pressing pressure of the compression molding is independently 12 MPa, and the holding time of the compression molding is independently 30 s; the holding temperature of the activation treatment is independently 650° C., and the holding time of the activation treatment is independently 30 h;

[0078] (3) using alumina sand as a burying medium to completely cover the 90WNiFe activated molded compact obtained in step (2), the thickness of the alumina sand being 10 mm, and adopting a completely buried sintering method; the 93WNiFe activated molded compact obtained in step (2) is sintered in a push rod type automatic sintering furnace in a bare sintering method to obtain 90WNiFe tungsten alloy material and 93WNiFe tungsten alloy material; the atmosphere of the sintering in the same furnace is hydrogen, the sintering temperature of the sintering in the same furnace is 1430° C., and the holding time of the sintering in the same furnace is 40 min;

[0079] (4) The 90WNiFe tungsten alloy material and the 93WNiFe tungsten alloy material obtained in step (3) are annealed in a vacuum furnace to obtain 90WNiFe tungsten alloy and 93WNiFe tungsten alloy; the vacuum degree of the annealing treatment is less than 1.33×10 - 2 Pa, the holding temperature of annealing treatment is 1050℃, and the holding time of annealing treatment is 2h.

[0080] Example 2

[0081] A method for preparing tungsten alloys with different compositions or different forming processes by sintering in the same furnace is as follows:

[0082] (1) Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 93:4.4:2.2:0.3:0.1 and then ball milled to obtain 93WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3.5 μm, the nickel powder has a Fischer-Strauss particle size of 1 μm, the iron powder has a Fischer-Strauss particle size of 6.5 μm, the cobalt powder has a Fischer-Strauss particle size of 1.5 μm, and the manganese powder has a Fischer-Strauss particle size of 7 μm; the ball-to-material ratio of the ball milling mixture is 2:1, and the ball milling mixing time is 18 h;

[0083] Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 95:3.2:1.6:0.15:0.05 and then ball-milled to obtain 95WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3 μm, the nickel powder has a Fischer-Strauss particle size of 3.5 μm, the iron powder has a Fischer-Strauss particle size of 7.5 μm, the cobalt powder has a Fischer-Strauss particle size of 1 μm, and the manganese powder has a Fischer-Strauss particle size of 8.5 μm; the ball-to-material ratio of the ball-milling mixture is 1:1, and the ball-milling mixing time is 12 h;

[0084] (2) The 93WNiFe mixed powder and the 95WNiFe mixed powder obtained in the step (1) are granulated, compression molded and activated to obtain 93WNiFe activated compression molded green sheets and 95WNiFe activated compression molded green sheets; the particle size of the granulation is independently 40-120 mesh; the pressing pressure of the compression molding is independently 20 MPa, and the holding time of the compression molding is independently 15 s; the holding temperature of the activation treatment is independently 800° C., and the holding time of the activation treatment is independently 24 h;

[0085] (3) using alumina sand as a burying medium to completely cover the 93WNiFe activated molded compact obtained in step (2), using a complete burying method, the thickness of the alumina sand is 10 mm, burying 1 / 2 of the 95WNiFe activated molded compact obtained in step (2) in the alumina sand, the thickness of the buried part of the alumina sand is 10 mm, using a 1 / 2 burying method, sintering in a push rod type automatic sintering furnace to obtain 93WNiFe tungsten alloy material and 95WNiFe tungsten alloy material; the atmosphere of the sintering in the same furnace is hydrogen, the sintering temperature of the sintering in the same furnace is 1460°C, and the holding time of the sintering in the same furnace is 45 min;

[0086] (4) The 93WNiFe tungsten alloy material and the 95WNiFe tungsten alloy material obtained in step (3) are annealed in a vacuum furnace to obtain 93WNiFe tungsten alloy and 95WNiFe tungsten alloy; the vacuum degree of the annealing treatment is less than 1.33×10 - 2 Pa, the holding temperature of annealing treatment is 1200℃, and the holding time of annealing treatment is 1h.

[0087] Example 3

[0088] A method for preparing tungsten alloys with different compositions or different forming processes by sintering in the same furnace is as follows:

[0089] (1) Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 93:4.4:2.2:0.3:0.1 and then ball milled to obtain 93WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3.5 μm, the nickel powder has a Fischer-Strauss particle size of 3 μm, the iron powder has a Fischer-Strauss particle size of 6 μm, the cobalt powder has a Fischer-Strauss particle size of 1 μm, and the manganese powder has a Fischer-Strauss particle size of 6.5 μm; the ball-to-material ratio of the ball milling mixture is 2:1, and the ball milling mixing time is 18 h;

[0090] Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 95:3.2:1.6:0.15:0.05 and then ball-milled to obtain 95WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3 μm, the nickel powder has a Fischer-Strauss particle size of 3.5 μm, the iron powder has a Fischer-Strauss particle size of 7.5 μm, the cobalt powder has a Fischer-Strauss particle size of 1 μm, and the manganese powder has a Fischer-Strauss particle size of 8.5 μm; the ball-to-material ratio of the ball-milling mixture is 1:1, and the ball-milling mixing time is 12 h;

[0091] (2) cold isostatic pressing the 93WNiFe mixed powder and the 95WNiFe mixed powder obtained in step (1) to obtain a 93WNiFe cold isostatic pressed blank and a 95WNiFe cold isostatic pressed blank; the pressing pressure of the cold isostatic pressing is independently 200 MPa, and the holding time of the cold isostatic pressing is independently 120 s;

[0092] (3) using alumina sand as a burying medium to completely cover the 93WNiFe cold isostatic pressed compact obtained in step (2), the thickness of the alumina sand being 10 mm, and using a complete burying method to bury 1 / 2 of the 95WNiFe cold isostatic pressed compact obtained in step (2) in the alumina sand, the thickness of the buried part of the alumina sand being 10 mm, and using a 1 / 2 burying method to sinter in a push rod type automatic sintering furnace to obtain 93WNiFe tungsten alloy material and 95WNiFe tungsten alloy material; the atmosphere of the sintering in the same furnace is hydrogen, the sintering temperature of the sintering in the same furnace is 1485° C., and the holding time of the sintering in the same furnace is 60 min;

[0093] (4) The 93WNiFe tungsten alloy material and the 95WNiFe tungsten alloy material obtained in step (3) are annealed in a vacuum furnace to obtain 93WNiFe tungsten alloy and 95WNiFe tungsten alloy; the vacuum degree of the annealing treatment is less than 1.33×10 - 2 Pa, the holding temperature of annealing treatment is 1000℃, and the holding time of annealing treatment is 2.5h.

[0094] Example 4

[0095] A method for preparing tungsten alloys with different compositions or different forming processes by sintering in the same furnace is as follows:

[0096] (1) Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 95:3.2:1.6:0.15:0.05 and then ball-milled to obtain a 95WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3 μm, the nickel powder has a Fischer-Strauss particle size of 3.5 μm, the iron powder has a Fischer-Strauss particle size of 7.5 μm, the cobalt powder has a Fischer-Strauss particle size of 1 μm, and the manganese powder has a Fischer-Strauss particle size of 8.5 μm; the ball-to-material ratio of the ball-milling mixture is 1:1, and the ball-milling mixing time is 12 h;

[0097] Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 97:1.8:0.9:0.25:0.05 and then ball-milled to obtain 97WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3.5 μm, the nickel powder has a Fischer-Strauss particle size of 2.5 μm, the iron powder has a Fischer-Strauss particle size of 5 μm, the cobalt powder has a Fischer-Strauss particle size of 2.5 μm, and the manganese powder has a Fischer-Strauss particle size of 7.5 μm; the ball-to-material ratio of the ball-milling mixture is 2:1, and the ball-milling mixing time is 24 hours;

[0098] (2) cold isostatic pressing the 95WNiFe mixed powder and the 97WNiFe mixed powder obtained in step (1) to obtain a 95WNiFe cold isostatic pressed blank and a 97WNiFe cold isostatic pressed blank; the pressing pressure of the cold isostatic pressing is independently 240 MPa, and the holding time of the cold isostatic pressing is independently 180 s;

[0099] (3) using alumina sand as a burying medium to completely cover the 95WNiFe cold isostatic pressed compact obtained in step (2), the thickness of the alumina sand being 10 mm, and adopting a completely buried sintering method, and sintering the 97WNiFe cold isostatic pressed compact obtained in step (2) in a push rod type automatic sintering furnace in a bare sintering method to obtain 95WNiFe tungsten alloy material and 97WNiFe tungsten alloy material; the atmosphere of the sintering in the same furnace is hydrogen, the sintering temperature of the sintering in the same furnace is 1530° C., and the holding time of the sintering in the same furnace is 40 min;

[0100] (4) The 95WNiFe tungsten alloy material and the 97WNiFe tungsten alloy material obtained in step (3) are annealed in a vacuum furnace to obtain 95WNiFe tungsten alloy and 97WNiFe tungsten alloy; the vacuum degree of the annealing treatment is less than 1.33×10 - 2 Pa, the holding temperature of annealing treatment is 1100℃, and the holding time of annealing treatment is 2h.

[0101] Example 5

[0102] A method for preparing tungsten alloys with different compositions or different forming processes by sintering in the same furnace is as follows:

[0103] (1) Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 93:4.4:2.2:0.3:0.1 and then ball milled to obtain 93WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3.5 μm, the nickel powder has a Fischer-Strauss particle size of 3 μm, the iron powder has a Fischer-Strauss particle size of 6 μm, the cobalt powder has a Fischer-Strauss particle size of 1 μm, and the manganese powder has a Fischer-Strauss particle size of 6.5 μm; the ball-to-material ratio of the ball milling mixture is 2:1, and the ball milling mixing time is 18 h;

[0104] (2) cold isostatic pressing a portion of the 93WNiFe mixed powder obtained in step (1) to obtain a 93WNiFe cold isostatic pressed blank; the pressing pressure of the cold isostatic pressing is 240 MPa, and the holding time of the cold isostatic pressing is 180 s;

[0105] The other part of the 93WNiFe mixed powder obtained in the step (1) is sequentially granulated, compression molded and activated to obtain a 93WNiFe activated compression molded compact; the particle size of the granulation is 40-120 mesh; the pressing pressure of the compression molding is 12 MPa, and the holding time of the compression molding is 30 seconds; the holding temperature of the activation treatment is 750°C, and the holding time of the activation treatment is 36 hours;

[0106] (3) burying 1 / 2 of the 93WNiFe cold isostatic pressed green sheet obtained in step (2) in alumina sand, wherein the thickness of the buried part of the alumina sand is 10 mm, and using a 1 / 2 burying method, using alumina sand as a burying medium to completely cover the 93WNiFe activated molded green sheet obtained in step (2), wherein the thickness of the alumina sand is 10 mm, and using a complete burying method, sintering in a push rod type automatic sintering furnace to obtain two 93WNiFe tungsten alloy materials; the atmosphere for the sintering in the same furnace is hydrogen, the sintering temperature for the sintering in the same furnace is 1460° C., and the holding time for the sintering in the same furnace is 45 min;

[0107] (4) The two 93WNiFe tungsten alloy materials obtained in step (3) are annealed in a vacuum furnace to obtain two 93WNiFe tungsten alloys; the vacuum degree of the annealing treatment is less than 1.33×10 -2 Pa, the holding temperature of annealing treatment is 1050℃, and the holding time of annealing treatment is 1.5h.

[0108] Example 6

[0109] A method for preparing tungsten alloys with different compositions or different forming processes by sintering in the same furnace is as follows:

[0110] (1) Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 95:3.2:1.6:0.15:0.05 and then ball-milled to obtain a 95WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3 μm, the nickel powder has a Fischer-Strauss particle size of 3.5 μm, the iron powder has a Fischer-Strauss particle size of 7.5 μm, the cobalt powder has a Fischer-Strauss particle size of 1 μm, and the manganese powder has a Fischer-Strauss particle size of 8.5 μm; the ball-to-material ratio of the ball-milling mixture is 1:1, and the ball-milling mixing time is 12 h;

[0111] (2) cold isostatic pressing a portion of the 95WNiFe mixed powder obtained in step (1) to obtain a 95WNiFe cold isostatic pressed blank; the pressing pressure of the cold isostatic pressing is 200 MPa, and the holding time of the cold isostatic pressing is 240 s;

[0112] The other part of the 95WNiFe mixed powder obtained in the step (1) is sequentially granulated, compression molded and activated to obtain a 95WNiFe activated compression molded compact; the particle size of the granulation is 40-120 mesh; the pressing pressure of the compression molding is 18 MPa, and the holding time of the compression molding is 20 s; the holding temperature of the activation treatment is 700° C., and the holding time of the activation treatment is 28 h;

[0113] (3) burying 1 / 2 of the 95WNiFe cold isostatic pressed green sheet obtained in step (2) in alumina sand, wherein the thickness of the buried part of the alumina sand is 10 mm, and using a 1 / 2 burying method, using alumina sand as a burying medium to completely cover the 95WNiFe activated molded green sheet obtained in step (2), wherein the thickness of the alumina sand is 10 mm, and using a complete burying method, sintering in a push rod type automatic sintering furnace to obtain two 95WNiFe tungsten alloy materials; the atmosphere for the sintering in the same furnace is hydrogen, the sintering temperature for the sintering in the same furnace is 1475° C., and the holding time for the sintering in the same furnace is 35 min;

[0114] (4) The two 95WNiFe tungsten alloy materials obtained in step (3) are annealed in a vacuum furnace to obtain 95WNiFe tungsten alloy and 95WNiFe tungsten alloy; the vacuum degree of the annealing treatment is less than 1.33×10 -2 Pa, the holding temperature of annealing treatment is 1200℃, and the holding time of annealing treatment is 2h.

[0115] Example 7

[0116] A method for preparing tungsten alloys with different compositions or different forming processes by sintering in the same furnace is as follows:

[0117] (1) Tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder are mixed in a mass ratio of 97:1.8:0.9:0.25:0.05, and then ball milled to obtain 97WNiFe mixed powder; the tungsten powder has a Fischer-Strauss particle size of 3.5 μm, the nickel powder has a Fischer-Strauss particle size of 5.5 μm, the iron powder has a Fischer-Strauss particle size of 5 μm, the cobalt powder has a Fischer-Strauss particle size of 2.5 μm, and the manganese powder has a Fischer-Strauss particle size of 7.5 μm; the ball-to-material ratio of the ball milling mixture is 2:1, and the ball milling mixing time is 24 h;

[0118] (2) cold isostatic pressing a portion of the 97WNiFe mixed powder obtained in step (1) to obtain a 95WNiFe cold isostatic pressed blank; the pressing pressure of the cold isostatic pressing is 220 MPa, and the holding time of the cold isostatic pressing is 180 s;

[0119] The other part of the 97WNiFe mixed powder obtained in the step (1) is sequentially granulated, compression molded and activated to obtain a 97WNiFe activated compression molded compact; the particle size of the granulation is 40-120 mesh; the pressing pressure of the compression molding is 30 MPa, and the holding time of the compression molding is 10 s; the holding temperature of the activation treatment is 800° C., and the holding time of the activation treatment is 28 h;

[0120] (3) The 97WNiFe cold isostatic pressed green sheet obtained in step (2) is subjected to bare sintering, and alumina sand is used as a burying medium to completely cover the 97WNiFe activated mold pressed green sheet obtained in step (2), wherein the thickness of the alumina sand is 10 mm, and the green sheet is sintered in a push rod type automatic sintering furnace to obtain two 97WNiFe tungsten alloy materials; the sintering atmosphere is hydrogen, the sintering temperature is 1515° C., and the holding time is 50 min;

[0121] (4) The two 97WNiFe tungsten alloy materials obtained in step (3) are annealed in a vacuum furnace to obtain two 97WNiFe tungsten alloys; the vacuum degree of the annealing treatment is less than 1.33×10 -2 Pa, the holding temperature of annealing treatment is 1150℃, and the holding time of annealing treatment is 3h.

[0122] The properties of the tungsten alloys prepared in Examples 1 to 7 were tested, and the results are shown in Table 1:

[0123] Table 1 Properties of tungsten alloys prepared in Examples 1 to 7

[0124]

[0125] It can be seen from Table 1 that when tungsten alloys with different tungsten contents and the same forming process are sintered in the same furnace, the obtained tungsten alloys have similar density and mechanical properties to other tungsten alloys with the same tungsten content. For example, the density and performance of the 93WNiFe tungsten alloys prepared in Examples 1 to 3 and 5 in Table 1 are basically equivalent, the density and performance of the 95WNiFe tungsten alloys prepared in Examples 2 to 4 and 6 are basically equivalent, and the density and performance of the 97WNiFe tungsten alloys prepared in Examples 4 and 7 are basically equivalent; when tungsten alloys with the same tungsten content and different forming processes are sintered in the same furnace, the obtained tungsten alloys have similar density and mechanical properties to other tungsten alloys with the same tungsten content. For example, the density and performance of the 97WNiFe tungsten alloys prepared in Example 5 in Table 1 are basically equivalent. The density and performance of the two 93WNiFe tungsten alloys prepared in Example 6 are basically equivalent, the density and performance of the two 95WNiFe tungsten alloys prepared in Example 6 are basically equivalent, and the density and performance of the two 97WNiFe tungsten alloys prepared in Example 7 are basically equivalent; the performance of the tungsten alloys prepared above fluctuates within the error range, and the mechanical properties of the tungsten alloys are not affected by sintering in the same furnace, indicating that the tungsten alloy preparation method provided by the present invention can solve the problem of long product production cycle and low equipment utilization rate due to frequent adjustment of sintering temperature during the production process of tungsten alloy materials with different tungsten contents or different forming processes, thereby reducing production costs and improving production efficiency.

[0126] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing tungsten alloys with different compositions or different forming processes by sintering in the same furnace comprises the following steps: (1) mixing raw materials to obtain mixed powder; the raw materials in step (1) include tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder; the tungsten powder has a Fischer-Strauss particle size of 2.5-3.5 μm, the nickel powder has a Fischer-Strauss particle size of 2.5-3.5 μm, the iron powder has a Fischer-Strauss particle size of 5-8 μm, the cobalt powder has a Fischer-Strauss particle size of 1-2.5 μm, and the manganese powder has a Fischer-Strauss particle size of 6-8.5 μm; (2) subjecting the mixed powder obtained in step (1) to granulation, compression molding and activation treatment in sequence to obtain an activated compression molded compact; and / or, subjecting the mixed powder obtained in step (1) to cold isostatic pressing to obtain a cold isostatic pressed green compact; (3) When the green compact is the activated molded green compact obtained in step (2), the activated molded green compact with low tungsten content is completely buried and the activated molded green compact with high tungsten content is 1 / 2 buried or bare, and the two are sintered in the same furnace to obtain a tungsten alloy material; the difference in tungsten content between the activated molded green compact with low tungsten content and the activated molded green compact with high tungsten content is 2-3wt.%; Alternatively, when the pressed green sheet is the cold isostatic pressed green sheet obtained in step (2), the cold isostatic pressed green sheet with low tungsten content is completely buried and the cold isostatic pressed green sheet with high tungsten content is 1 / 2 buried or bare, and the tungsten alloy material is sintered in the same furnace; the difference in tungsten content between the cold isostatic pressed green sheet with low tungsten content and the cold isostatic pressed green sheet with high tungsten content is 2-3wt.%; Alternatively, when the pressed green sheet is the activated mold pressed green sheet and the cold isostatic pressed green sheet obtained in step (2), the activated mold pressed green sheet is completely buried and the cold isostatic pressed green sheet is 1 / 2 buried or bare, and the tungsten alloy material is sintered in the same furnace; the tungsten content in the activated mold pressed green sheet and the cold isostatic pressed green sheet is the same; In the step (3), the atmosphere for sintering in the same furnace is hydrogen, the sintering temperature for sintering in the same furnace is 1350-1560° C., and the holding time for sintering in the same furnace is 30-60 min; (4) annealing the tungsten alloy material obtained in step (3) to obtain a tungsten alloy; The vacuum degree of the annealing treatment in step (4) is less than 1.33×10 -2 Pa, the holding temperature of annealing treatment is 1000~1200℃, and the holding time of annealing treatment is 1~3h; In the step (4), the chemical composition of the tungsten alloy includes, by mass percentage: Tungsten: 85~97%, Nickel: 1.5~10%, Iron: 0.5~5%, Co: 0.1~0.6% and Manganese: 0.05~0.15%.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the tungsten powder, nickel powder, iron powder, cobalt powder and manganese powder is (85-97): (1.5-10): (0.5-5): (0.1-0.6): (0.05-0.15).

3. The preparation method according to claim 1, characterized in that: In the step (2), the compression molding pressure is 10-30 MPa, and the holding time of the compression molding is 10-30 s.

4. The preparation method according to claim 1, characterized in that: The holding temperature of the activation treatment in step (2) is 600-800° C., and the holding time of the activation treatment is 24-36 hours.

5. The preparation method according to claim 1, characterized in that: In the step (2), the pressing pressure of the cold isostatic pressing is 120-240 MPa, and the holding time of the cold isostatic pressing is 60-240 s.

6. The preparation method according to claim 1, characterized in that: The medium used in the complete burial method or the 1 / 2 burial method in step (3) is alumina sand.

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