A W-Re alloy precursor and a method for preparing a high-density and high-hardness W-Re alloy

Abstract

The invention belongs to the technical field of powder metallurgy, and particularly relates to a preparation method of a W-Re alloy precursor and a high-density and high-hardness W-Re alloy. Hydrogen peroxide dissolves tungsten powder in waste tungsten powder and converts it into soluble polytungstic acid to form a polytungstic acid-hydrogen peroxide mixed solution, and then rhenium powder is added. The rhenium powder forms a low-valent rhenium compound soluble in water in the mixed solution, and the polytungstate reacts with the heteroatom Re to form a heteropolyacid anion cluster with a multi-nuclear structure, thereby achieving the purpose of tungsten coating rhenium, so that the segregation of rhenium can be suppressed in the process of evaporation and crystallization, and the rhenium is evenly distributed in the precursor powder. The nano W-Re alloy powder prepared by the invention has a large number of whiskers in morphology, can improve the density and hardness of the W-Re alloy, and its density is ≥96.8%, and HV30 is ≥590.

Description

Technical Field

[0001] The invention belongs to the technical field of powder metallurgy, and specifically relates to a preparation method of a W-Re alloy precursor and a high-density and high-hardness W-Re alloy. Background Art

[0002] In modern industry, tungsten-rhenium alloys are highly valued for their excellent high-temperature performance and mechanical strength, especially in the aerospace and military fields. At present, most W-Re alloy precursors are prepared by high-energy ball milling, which is easy to introduce impurities and has negative effects such as hard agglomeration and micro-stress. Other preparation methods, such as solid-liquid doping to prepare W-Re alloy precursors, have problems such as local enrichment of Re and uneven distribution of components. These will make tungsten-rhenium alloys face the challenges of insufficient density and strength.

[0003] The treatment and recycling of waste tungsten powder has always been an important research direction. Waste tungsten powder includes the screened material, dirty material, tungsten wire, tungsten-based material, iron filings polished from the reduction boat, etc. The usual treatment method for these wastes is to oxidize the tungsten waste and then dissolve it in ammonia. The amount of dust generated in the oxidation process is very huge, which is not conducive to the health of the operators and the recovery of tungsten. Ammonia dissolution will produce a large amount of wastewater, which increases the cost of tungsten recovery for enterprises. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the main purpose of the present invention is to propose a W-Re alloy precursor and a method for preparing a high-density and high-hardness W-Re alloy, which can not only realize the efficient recovery and reuse of waste tungsten resources, but also provide a new way for the preparation of high-performance W-Re alloy materials.

[0005] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0006] A method for preparing a W-Re alloy precursor comprises the following steps:

[0007] S1. Add waste tungsten powder into hydrogen peroxide, and then filter to obtain a mixed solution of peroxytungstic acid-hydrogen peroxide;

[0008] S2, adding rhenium powder to the mixed solution of peroxytungstic acid-hydrogen peroxide and then performing ultrasonic treatment;

[0009] S3, then evaporating and crystallizing the solution;

[0010] S4, calcining the crystals to obtain composite powder;

[0011] S5. The composite powder is placed in a tubular furnace for hydrogen reduction to obtain a W-Re alloy precursor rich in whisker-like tungsten.

[0012] As a preferred embodiment of the method for preparing a W-Re alloy precursor according to the present invention, in step S1, the waste tungsten powder is pretreated before being added to the hydrogen peroxide: the waste tungsten powder is filtered after being washed with dilute hydrochloric acid to remove impurities inside the waste tungsten powder, and then the filter residue is washed with pure water and dried.

[0013] As a preferred embodiment of the method for preparing a W-Re alloy precursor according to the present invention, in step S1, the concentration of hydrogen peroxide is 25-35wt%, and the liquid-to-solid ratio of hydrogen peroxide to waste tungsten powder is (2-6) mL:1 g.

[0014] As a preferred embodiment of the method for preparing a W-Re alloy precursor according to the present invention, in step S2, the quality of the rhenium powder satisfies:

[0015] Rhenium powder mass / (mass of W in waste tungsten powder + mass of rhenium powder) = 1~10%.

[0016] As a preferred embodiment of the method for preparing a W-Re alloy precursor according to the present invention, in step S2, the ultrasonic treatment time is 4-8 hours and the temperature is 70-90°C.

[0017] As a preferred embodiment of the method for preparing a W-Re alloy precursor according to the present invention, in step S3, the temperature of evaporation and crystallization is 90-120° C. and the time is 5-8 hours.

[0018] As a preferred embodiment of the method for preparing a W-Re alloy precursor according to the present invention, in step S4, the calcination temperature is 600-750° C. and the calcination time is 3-6 hours.

[0019] As a preferred embodiment of the method for preparing a W-Re alloy precursor described in the present invention, in which: in the step S5, the reduction process is: the first-stage reduction temperature is 300~350°C, the reduction time is 0.5~1h, the second-stage reduction temperature is 500~550°C, the reduction time is 1~3h, the third-stage reduction temperature is 750~850°C, and the reduction time is 1~3h; the hydrogen flow rate is 3~5L / min, and the heating rate before the reduction temperature of each stage reaches the temperature is 10°C / min.

[0020] To solve the above technical problem, according to another aspect of the present invention, the present invention provides the following technical solution:

[0021] A method for preparing a high-density and high-hardness W-Re alloy comprises: pressing and sintering the W-Re alloy precursor to obtain a high-density and high-hardness W-Re alloy.

[0022] As a preferred embodiment of the method for preparing a high-density and high-hardness W-Re alloy described in the present invention, the pressing pressure is 280~420MPa, and the pressure is maintained for 15~20s; the SPS technology is used for sintering, and the temperature is increased to 1300~1500℃ at a heating rate of 90~100℃ / min, and the temperature is maintained for 5~10min. When the temperature is less than 1300℃, the sintering pressure is 5~10MPa, and when the temperature is 1300~1500℃, the sintering pressure is 20~30MPa, and then the high-density and high-hardness W-Re alloy is obtained by cooling with the furnace.

[0023] To solve the above technical problem, according to another aspect of the present invention, the present invention provides the following technical solution:

[0024] A high-density and high-hardness W-Re alloy is prepared by adopting the above-mentioned preparation method of the high-density and high-hardness W-Re alloy.

[0025] As a preferred embodiment of the high-density and high-hardness W-Re alloy described in the present invention, the density of the high-density and high-hardness W-Re alloy is ≥96.8%, and HV30 is ≥590.

[0026] The beneficial effects of the present invention are as follows:

[0027] The present invention provides a preparation method of a W-Re alloy precursor and a high-density and high-hardness W-Re alloy. The preparation of the high-density and high-hardness W-Re alloy and its precursor is carried out in coordination with the recovery of waste tungsten powder, which can improve the added value of the recovered products; rhenium can refine the grains during the reduction process, and the parameters of the reduction process are controlled, so that the W-Re precursor powder is easy to be nanometer-sized; hydrogen peroxide dissolves the tungsten powder in the waste tungsten powder and converts it into soluble polytungstic acid to form a polytungstic acid-hydrogen peroxide mixed solution, and then rhenium powder is added The rhenium powder forms a low-valent rhenium compound soluble in water in the mixed solution, and the polytungstate reacts with the heteroatom Re to form a heteropolyacid anion cluster with a multi-nuclear structure, thereby achieving the purpose of tungsten coating rhenium, so that the segregation of rhenium can be suppressed during the evaporation and crystallization process, and the rhenium is evenly distributed in the precursor powder; the nano W-Re alloy powder prepared by the present invention has a large number of whiskers, which can improve the density and hardness of the W-Re alloy, and its density is ≥96.8%, and HV30 is ≥590. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0029] Figure 1This is a SEM image of the W—Re alloy precursor rich in whisker-like tungsten prepared in Example 1 of the present invention.

[0030] Figure 2 This is the SEM image of the ordinary W-Re alloy precursor.

[0031] Figure 3 This is an XRD comparison diagram of the W-Re alloy precursor rich in whisker-like tungsten prepared in Example 1 and a common W-Re alloy precursor.

[0032] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0034] According to one aspect of the present invention, the present invention provides the following technical solution:

[0035] A method for preparing a W-Re alloy precursor comprises the following steps:

[0036] S1. Add waste tungsten powder into hydrogen peroxide, and then filter to obtain a mixed solution of peroxytungstic acid-hydrogen peroxide;

[0037] S2, adding rhenium powder to the mixed solution of peroxytungstic acid-hydrogen peroxide and then performing ultrasonic treatment;

[0038] S3, then evaporating and crystallizing the solution;

[0039] S4, calcining the crystals to obtain composite powder;

[0040] S5. The composite powder is placed in a tubular furnace for hydrogen reduction to obtain a W-Re alloy precursor rich in whisker-like tungsten.

[0041] Preferably, in step S1, the waste tungsten powder is pretreated before being added to the hydrogen peroxide: the waste tungsten powder is filtered after being washed with dilute hydrochloric acid to remove impurities inside, and then the filter residue is washed with pure water and dried.

[0042] Preferably, in step S1, the concentration of hydrogen peroxide is 25-35wt%, and the liquid-to-solid ratio of hydrogen peroxide to waste tungsten powder is (2-6)mL:1g.

[0043] Preferably, in step S2, the quality of rhenium powder satisfies:

[0044] Rhenium powder mass / (mass of W in waste tungsten powder + mass of rhenium powder) = 1~10%.

[0045] Preferably, in step S2, the ultrasonic treatment time is 4-8 hours and the temperature is 70-90°C.

[0046] Preferably, in step S3, the temperature of evaporation crystallization is 90-120° C., and the time is 5-8 hours.

[0047] Preferably, in step S4, the calcination temperature is 600-750° C. and the calcination time is 3-6 hours.

[0048] Preferably, in step S5, the reduction process is: the first stage reduction temperature is 300-350°C, the reduction time is 0.5-1h, the second stage reduction temperature is 500-550°C, the reduction time is 1-3h, the third stage reduction temperature is 750-850°C, the reduction time is 1-3h; the hydrogen flow rate is 3-5L / min, and the heating rate before the reduction temperature of each stage reaches the temperature is 10°C / min.

[0049] According to another aspect of the present invention, the present invention provides the following technical solution:

[0050] A method for preparing a high-density and high-hardness W-Re alloy comprises: pressing and sintering the W-Re alloy precursor to obtain a high-density and high-hardness W-Re alloy.

[0051] Preferably, the pressing pressure is 280~420MPa, and the pressure is maintained for 15~20s; the SPS technology is used for sintering, and the temperature is increased to 1300~1500℃ at a heating rate of 90~100℃ / min, and the temperature is maintained for 5~10min. The sintering pressure is 5~10MPa when the temperature is less than 1300℃, and the sintering pressure is 20~30MPa when the temperature is 1300~1500℃. Then, the high-density and high-hardness W-Re alloy is obtained by cooling with the furnace.

[0052] According to another aspect of the present invention, the present invention provides the following technical solution:

[0053] A high-density and high-hardness W-Re alloy is prepared by adopting the above-mentioned preparation method of the high-density and high-hardness W-Re alloy.

[0054] Preferably, the density of the high-density and high-hardness W—Re alloy is ≥96.8%, and HV30 is ≥590.

[0055] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0056] Example 1

[0057] A method for preparing a W-Re alloy precursor comprises the following steps:

[0058] S1. Add waste tungsten powder to hydrogen peroxide, and then filter to obtain a peroxytungstic acid-hydrogen peroxide mixed solution; the waste tungsten powder is pretreated before adding hydrogen peroxide: use dilute hydrochloric acid to wash away impurities inside the waste tungsten powder and then filter, then use pure water to wash the filter residue, and then dry the filter residue; the concentration of hydrogen peroxide is 30wt%, and the liquid-solid ratio of hydrogen peroxide to waste tungsten powder is 2mL:1g;

[0059] S2. Add rhenium powder to the mixed solution of peroxytungstic acid and hydrogen peroxide and then perform ultrasonic treatment; the mass of rhenium powder satisfies: mass of rhenium powder / (mass of W in waste tungsten powder + mass of rhenium powder) = 5%; the ultrasonic treatment time is 5h and the temperature is 80°C;

[0060] S3, then evaporating and crystallizing the solution; the evaporation and crystallization temperature is 100°C and the time is 6 hours;

[0061] S4, calcining the crystal to obtain a composite powder; the calcination temperature is 650°C and the time is 4 hours;

[0062] S5. The composite powder is placed in a tubular furnace for hydrogen reduction. The reduction process is as follows: the first stage reduction temperature is 300°C, the reduction time is 0.5h, the second stage reduction temperature is 500°C, the reduction time is 2h, the third stage reduction temperature is 800°C, and the reduction time is 2h; the hydrogen flow rate is 5L / min, and the heating rate before each stage reduction temperature reaches the temperature is 10°C / min, and a W-Re alloy precursor rich in whisker-like tungsten is obtained, and its SEM image is as shown in Figure 1 shown.

[0063] The W-Re alloy precursor prepared in this embodiment was pressed and sintered, the pressing pressure was 300 MPa, and the pressure was maintained for 15 seconds; the SPS technology was used for sintering, the temperature was raised to 1430°C at a heating rate of 100°C / min, and the temperature was maintained for 8 minutes. The sintering pressure was 6 MPa when the temperature was less than 1300°C, and the sintering pressure was 25 MPa when the temperature was 1300-1430°C. After that, the high-density and high-hardness W-Re alloy was obtained by cooling with the furnace, and the density was 97.35%, and the HV30 was 614.

[0064] Example 2

[0065] A method for preparing a W-Re alloy precursor comprises the following steps:

[0066] S1. Add waste tungsten powder to hydrogen peroxide, and then filter to obtain a peroxytungstic acid-hydrogen peroxide mixed solution; the waste tungsten powder is pretreated before adding hydrogen peroxide: use dilute hydrochloric acid to wash away impurities inside the waste tungsten powder and then filter, then use pure water to wash the filter residue, and then dry the filter residue; the concentration of hydrogen peroxide is 25wt%, and the liquid-solid ratio of hydrogen peroxide to waste tungsten powder is 5mL:1g;

[0067] S2. Add rhenium powder to the mixed solution of peroxytungstic acid and hydrogen peroxide and then perform ultrasonic treatment; the mass of rhenium powder satisfies: mass of rhenium powder / (mass of W in waste tungsten powder + mass of rhenium powder) = 10%; the ultrasonic treatment time is 7h and the temperature is 90°C;

[0068] S3, then evaporate and crystallize the solution; the evaporation and crystallization temperature is 120°C and the time is 5h;

[0069] S4, calcining the crystal to obtain a composite powder; the calcination temperature is 600°C and the time is 5h;

[0070] S5. The composite powder is placed in a tubular furnace for hydrogen reduction. The reduction process is as follows: the first stage reduction temperature is 300°C, the reduction time is 1h, the second stage reduction temperature is 500°C, the reduction time is 3h, the third stage reduction temperature is 830°C, and the reduction time is 1.5h; the hydrogen flow rate is 3L / min, and the heating rate before each stage reduction temperature reaches the temperature is 10°C / min, to obtain a W-Re alloy precursor rich in whisker-like tungsten.

[0071] The W-Re alloy precursor prepared in this embodiment was pressed and sintered, with a pressing pressure of 400 MPa and a pressure holding period of 18 seconds. The SPS technology was used for sintering, and the temperature was raised to 1380°C at a heating rate of 90°C / min and kept for 10 minutes. The sintering pressure was 8 MPa when the temperature was less than 1300°C, and the sintering pressure was 30 MPa when the temperature was 1300-1380°C. After that, the high-density and high-hardness W-Re alloy was obtained by cooling with the furnace, and the density was 97.51% and the HV30 was 623.

[0072] Example 3

[0073] A method for preparing a W-Re alloy precursor comprises the following steps:

[0074] S1. Add waste tungsten powder to hydrogen peroxide, and then filter to obtain a peroxytungstic acid-hydrogen peroxide mixed solution; the waste tungsten powder is pretreated before adding hydrogen peroxide: use dilute hydrochloric acid to wash away impurities inside the waste tungsten powder and then filter, then use pure water to wash the filter residue, and then dry the filter residue; the concentration of hydrogen peroxide is 35wt%, and the liquid-solid ratio of hydrogen peroxide to waste tungsten powder is 4mL:1g;

[0075] S2. Add rhenium powder to the peroxytungstic acid-hydrogen peroxide mixed solution and then perform ultrasonic treatment; the mass of rhenium powder satisfies: mass of rhenium powder / (mass of W in waste tungsten powder + mass of rhenium powder) = 5%; the ultrasonic treatment time is 6 hours and the temperature is 70°C;

[0076] S3, then evaporate and crystallize the solution; the evaporation and crystallization temperature is 90°C and the time is 8h;

[0077] S4, calcining the crystal to obtain a composite powder; the calcination temperature is 750°C and the time is 3h;

[0078] S5. The composite powder is placed in a tubular furnace for hydrogen reduction. The reduction process is as follows: the first stage reduction temperature is 350°C, the reduction time is 0.5h, the second stage reduction temperature is 500°C, the reduction time is 2h, the third stage reduction temperature is 850°C, and the reduction time is 2h; the hydrogen flow rate is 4L / min, and the heating rate before each stage reduction temperature reaches the temperature is 10°C / min, to obtain a W-Re alloy precursor rich in whisker-like tungsten.

[0079] The W-Re alloy precursor prepared in this embodiment was pressed and sintered, the pressing pressure was 320 MPa, and the pressure was maintained for 20 seconds; the SPS technology was used for sintering, the temperature was raised to 1410°C at a heating rate of 100°C / min, and the temperature was maintained for 8 minutes. The sintering pressure was 6 MPa when the temperature was less than 1300°C, and the sintering pressure was 25 MPa when the temperature was 1300-1410°C. After that, the high-density and high-hardness W-Re alloy was obtained by cooling with the furnace, and the density was 96.89% and the HV30 was 593.

[0080] Example 4

[0081] A method for preparing a W-Re alloy precursor comprises the following steps:

[0082] S1. Add waste tungsten powder to hydrogen peroxide, and then filter to obtain a peroxytungstic acid-hydrogen peroxide mixed solution; the waste tungsten powder is pretreated before adding hydrogen peroxide: use dilute hydrochloric acid to wash away impurities inside the waste tungsten powder and then filter, then use pure water to wash the filter residue, and then dry the filter residue; the concentration of hydrogen peroxide is 35wt%, and the liquid-solid ratio of hydrogen peroxide to waste tungsten powder is 4mL:1g;

[0083] S2. Add rhenium powder to the mixed solution of peroxytungstic acid and hydrogen peroxide and then perform ultrasonic treatment; the mass of rhenium powder satisfies: mass of rhenium powder / (mass of W in waste tungsten powder + mass of rhenium powder) = 1%; the ultrasonic treatment time is 4 hours and the temperature is 90°C;

[0084] S3, then evaporate and crystallize the solution; the evaporation and crystallization temperature is 110°C and the time is 5h;

[0085] S4, calcining the crystal to obtain a composite powder; the calcination temperature is 750°C and the time is 4 hours;

[0086] S5. The composite powder is placed in a tubular furnace for hydrogen reduction. The reduction process is as follows: the first stage reduction temperature is 325°C, the reduction time is 0.5h, the second stage reduction temperature is 500°C, the reduction time is 3h, the third stage reduction temperature is 830°C, and the reduction time is 2h; the hydrogen flow rate is 5L / min, and the heating rate before each stage reduction temperature reaches the temperature is 10°C / min, to obtain a W-Re alloy precursor rich in whisker-like tungsten.

[0087] The W-Re alloy precursor prepared in this embodiment was pressed and sintered, with a pressing pressure of 420 MPa and a pressure holding time of 20 seconds. The SPS technology was used for sintering, and the temperature was raised to 1500°C at a heating rate of 100°C / min and kept at this temperature for 10 minutes. The sintering pressure was 6 MPa when the temperature was less than 1300°C, and 25 MPa when the temperature was 1300-1500°C. The alloy was then cooled in the furnace to obtain a high-density and high-hardness W-Re alloy with a density of 97.84% and an HV30 of 604.

[0088] Comparative Example 1

[0089] The difference from Example 1 is that in step S1, the concentration of hydrogen peroxide is 10 wt %, and the liquid-to-solid ratio of hydrogen peroxide to waste tungsten powder is 8 mL:1 g.

[0090] The waste tungsten powder in this comparative example could not be completely dissolved and the preparation failed.

[0091] Comparative Example 2

[0092] The difference from Example 1 is that the mass of rhenium powder in step S2 satisfies: mass of rhenium powder / (mass of W in waste tungsten powder+mass of rhenium powder)=15%.

[0093] The rhenium powder in this comparative example was not completely dissolved and the preparation failed.

[0094] Comparative Example 3

[0095] The difference from Example 1 is that the calcination temperature in step S4 is 800°C.

[0096] The SEM image of the common W-Re alloy precursor prepared in this comparative example is as follows Figure 2 As shown in FIG. 1 , the density of the W-Re alloy prepared by the method is 92.43%, and the HV30 is 483. The XRD comparison diagram of the W-Re alloy precursor rich in whisker-like tungsten prepared in Example 1 and the ordinary W-Re alloy precursor is shown in FIG. Figure 3 As shown, the increase in sintering temperature will lead to the growth of W-Re alloy precursor grains, thereby destroying the change of W crystal form by Re, and no whisker-like tungsten powder is generated, resulting in a decrease in W-Re density and hardness.

[0097] Comparative Example 4

[0098] The difference from Example 1 is that in step S5, the first stage reduction temperature is 750°C, the second stage reduction temperature is 850°C, and the third stage reduction temperature is 950°C.

[0099] In this comparative example, a common W-Re alloy precursor is prepared. The W-Re alloy prepared by using the precursor has a density of 93.46% and an HV30 of 522.

[0100] Comparative Example 5

[0101] The difference from Example 1 is that the prepared W-Re alloy precursor is pressed and sintered, the pressing pressure is 300 MPa, and the pressure is maintained for 15 seconds; the SPS technology is used for sintering, and the temperature is increased to 1700°C at a heating rate of 100°C / min, and the temperature is maintained for 20 minutes. The sintering pressure is 15 MPa when the temperature is less than 1300°C, and the sintering pressure is 50 MPa when the temperature is 1300-1700°C. After that, the W-Re alloy is obtained by cooling with the furnace, and the density is 94.25% and the HV30 is 543.

[0102] Comparative Example 6

[0103] The difference from Example 1 is that in step S1, the pretreated waste tungsten powder is mixed with rhenium powder and then hydrogen peroxide is added.

[0104] This comparative example prepares a common W-Re alloy precursor, and the W-Re alloy prepared by using the precursor has a density of 94.14% and an HV30 of 528. The powder mixed in the manner described in this comparative example cannot form a situation where tungsten-coated rhenium is formed.

[0105] It can be seen from the above embodiments and comparative examples that the present invention will prepare high-density and high-hardness W-Re alloy and its precursor in coordination with the recovery of waste tungsten powder, which can improve the added value of the recovered products; rhenium can refine the grains during the reduction process, and the parameter control of the reduction process makes the W-Re precursor powder easy to become nanometer-level; hydrogen peroxide dissolves the tungsten powder in the waste tungsten powder and converts it into soluble polytungstic acid to form a polytungstic acid-hydrogen peroxide mixed solution, and then rhenium powder is added. The rhenium powder forms a low-valent rhenium compound soluble in water in the mixed solution, and the polytungstate will polymerize with the heteroatom Re to form a heteropolyacid anion cluster with a multi-nuclear structure, thereby achieving the purpose of tungsten coating rhenium, so that the segregation of rhenium can be suppressed during the evaporation and crystallization process, and rhenium is evenly distributed in the precursor powder; the nano W-Re alloy powder prepared by the present invention has a large number of whiskers in morphology, which can improve the density and hardness of the W-Re alloy, and its density is ≥96.8%, and HV30 ≥590.

[0106] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a W-Re alloy precursor, characterized in that: The steps include: S1. Add waste tungsten powder into hydrogen peroxide, and then filter to obtain a mixed solution of peroxytungstic acid-hydrogen peroxide; S2, adding rhenium powder to the mixed solution of peroxytungstic acid-hydrogen peroxide and then performing ultrasonic treatment; S3, then evaporating and crystallizing the solution; S4, calcining the crystals to obtain composite powder; S5. The composite powder is placed in a tubular furnace for hydrogen reduction to obtain a W-Re alloy precursor rich in whisker-like tungsten.

2. The method for preparing a W-Re alloy precursor according to claim 1, characterized in that: In the step S1, the waste tungsten powder is pretreated before being added to the hydrogen peroxide: the waste tungsten powder is filtered after being washed with dilute hydrochloric acid to remove impurities inside, and then the filter residue is washed with pure water and dried.

3. The method for preparing a W-Re alloy precursor according to claim 1, characterized in that: In the step S1, the concentration of hydrogen peroxide is 25-35wt%, and the liquid-to-solid ratio of hydrogen peroxide to waste tungsten powder is (2-6)mL:1g.

4. The method for preparing a W-Re alloy precursor according to claim 1, characterized in that: In step S2, the quality of rhenium powder satisfies: Rhenium powder mass / (mass of W in waste tungsten powder + mass of rhenium powder) = 1~10%.

5. The method for preparing a W-Re alloy precursor according to claim 1, characterized in that: In step S2, the ultrasonic treatment time is 4-8 hours and the temperature is 70-90°C.

6. The method for preparing a W-Re alloy precursor according to claim 1, characterized in that: In step S3, the temperature of evaporation crystallization is 90-120° C., and the time is 5-8 hours.

7. The method for preparing a W-Re alloy precursor according to claim 1, characterized in that: In step S4, the calcination temperature is 600-750° C. and the calcination time is 3-6 hours.

8. The method for preparing a W-Re alloy precursor according to claim 1, characterized in that: In step S5, the reduction process is as follows: the first stage reduction temperature is 300-350°C, the reduction time is 0.5-1h, the second stage reduction temperature is 500-550°C, the reduction time is 1-3h, the third stage reduction temperature is 750-850°C, the reduction time is 1-3h; the hydrogen flow rate is 3-5L / min, and the heating rate before the reduction temperature of each stage reaches the temperature is 10°C / min.

9. A method for preparing a high-density and high-hardness W-Re alloy, characterized in that: include: The W-Re alloy precursor prepared by the method for preparing a W-Re alloy precursor according to any one of claims 1 to 8 is pressed and sintered, the pressing pressure is 280-420 MPa, and the pressure is maintained for 15-20 seconds; The sintering adopts SPS technology, which heats up to 1300~1500℃ at a heating rate of 90~100℃ / min and keeps warm for 5~10min. The sintering pressure is 5~10MPa when the temperature is less than 1300℃ and 20~30MPa when the temperature is 1300~1500℃. Then, the high-density and high-hardness W-Re alloy is obtained by cooling in the furnace.

10. A high-density and high-hardness W-Re alloy, prepared by the method for preparing a high-density and high-hardness W-Re alloy according to claim 9, characterized in that: Density ≥96.8%, HV30 ≥590.

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