Tungsten alloy filament and preparation method thereof

Abstract

The invention relates to the technical field of alloy processing, and particularly discloses a tungsten alloy filament and a preparation method thereof. The tungsten alloy filament provided by the invention comprises the following components in percentage by mass: 1.8%-2% of Cu, 0.1%-0.12% of C, 0.5%-0.8% of Ti, 0.7%-0.9% of Cr, 5.5%-7.5% of Mo and the balance of W and inevitable impurities. According to the tungsten alloy filament and the preparation method thereof, the adding elements and the adding amount in the tungsten alloy are reasonably controlled, and the tungsten alloy filament provided by the invention has excellent ductility and strength through composite strengthening of all the elements and has important practical value for actual production.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy processing, and in particular to a tungsten alloy filament and a preparation method thereof. Background Art

[0002] Tungsten alloy is mainly based on tungsten, and has excellent properties such as high melting point and high strength. Therefore, tungsten alloy is usually used in printed battery materials. However, the existing tungsten alloy filaments for printed batteries still have many disadvantages, mainly including that the existing tungsten alloy filaments have high hardness, which makes them complicated to process, which not only limits their application in printed batteries that require complex shapes or structures, but also may increase the cost in the manufacturing process; the existing tungsten alloy filaments are relatively brittle and easily broken by external forces. During the manufacturing and use of printed batteries, if they are improperly handled or impacted by external forces, they may cause the tungsten alloy filaments to break, thereby affecting the performance and life of the battery. Therefore, it is urgent to provide a tungsten alloy filament and a preparation method thereof to solve the problem of low strength and poor ductility of existing tungsten alloy filaments. Summary of the invention

[0003] In view of the problem that the existing tungsten alloy has low strength and poor ductility, the present invention provides a tungsten alloy filament and a preparation method thereof.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0005] The first aspect of the present invention provides a tungsten alloy filament, comprising the following components in percentage by mass: Cu: 1.8% to 2%, C: 0.1% to 0.12%, Ti: 0.5% to 0.8%, Cr: 0.7% to 0.9%, Mo: 5.5% to 7.5%, and the remainder being W and unavoidable impurities.

[0006] Compared with the prior art, the tungsten alloy filaments provided by the present invention have good compatibility with copper and tungsten. By controlling the amount of copper added, the machinability of the tungsten alloy is further improved, the ductility of the tungsten alloy is improved, and copper can also promote the dispersion of other elements in the tungsten alloy; further, the present invention also adds carbon, titanium and chromium, and a small amount of tungsten carbide is formed between tungsten and carbon to enhance the grain boundary strength, thereby improving the strength of the alloy to a certain extent; titanium can form titanium carbide with carbon to improve the strength of the alloy, and the addition of titanium can also reduce the brittleness of the alloy, thereby improving the ductility of the alloy; chromium and tungsten form a stable lattice structure, thereby improving the strength of the tungsten alloy, and the addition of chromium will improve the ductility of the tungsten alloy to a certain extent; molybdenum and tungsten can reduce the brittle transition temperature of the alloy through the joint action, thereby improving the ductility of the tungsten alloy filaments.

[0007] The present invention reasonably controls the added elements and the added amounts in the tungsten alloy, and through composite strengthening between the elements, the tungsten alloy filament provided by the present invention has excellent ductility and strength, and has important practical value for actual production.

[0008] The second aspect of the present invention provides a method for preparing the above-mentioned tungsten alloy filament, comprising the following steps:

[0009] Step 1, Cu, C, Ti, Cr, Mo and W are uniformly mixed and pressed to obtain a green body;

[0010] Step 2, sintering the green compact at 1800° C. to 2000° C. in an inert atmosphere to obtain a sintered compact;

[0011] Step 3, performing a first rotary forging on the sintered blank at 1380° C. to 1420° C., cooling to room temperature, and then freezing at -160° C. to -140° C. to obtain a first rod;

[0012] Step 4, performing a second rotary forging on the first rod at 1280° C. to 1320° C., cooling to room temperature and then freezing at -130° C. to -110° C. to obtain a second rod;

[0013] Step 5, performing a first annealing on the second rod at 950° C. to 1050° C. to obtain a primary annealed rod; performing a second annealing on the primary annealed rod at 700° C. to 750° C., and water cooling to obtain an annealed rod;

[0014] Step 6: Drawing the annealed rod to obtain tungsten alloy filaments.

[0015] Compared with the prior art, in the preparation method of tungsten alloy filaments provided by the present invention, by sintering the green body at a specific temperature, the powders of each element can be fully bonded to each other, the pores and defects in the green body can be reduced, and a dense sintered body can be formed. In addition, the specific temperature can also make each element in the tungsten alloy be dissolved in the alloy to form precipitates such as titanium carbide, thereby improving the strength and elongation of the tungsten alloy filaments. The present invention performs a first rotary forging on the sintered body at a specific temperature, which can refine the grains, increase the number of grains, release part of the internal stress, and thus improve the ductility and strength of the tungsten alloy filaments. The second rotary forging is performed at a specific temperature to further reduce the grain size and improve the distribution of precipitates at the grain boundary, so that the prepared tungsten alloy filaments have both high strength and ductility. After forging and the second rotary forging, deep cryogenic treatment is performed, which can further refine the grains and improve the strength and ductility of the tungsten alloy filaments; the first annealing is performed at a specific temperature, which can eliminate the processing stress generated by the alloy after rotary forging and improve the ductility of the tungsten alloy filaments, and the preferred temperature of the first annealing can also ensure that precipitates such as titanium carbide and tungsten carbide are not destroyed, thereby ensuring that the tungsten alloy filaments have high strength; the temperature during the second annealing is lower than that of the first annealing, and low-temperature annealing can further optimize the grain structure and reduce the residual stress in the tungsten alloy filaments, thereby further improving the strength and elongation of the tungsten alloy filaments; water cooling treatment is performed after the second annealing, which is also beneficial to refine the grains, improve the machinability of the tungsten alloy filaments, and ensure the high strength performance of the tungsten alloy filaments.

[0016] Preferably, in step 1, the Cu, Ti, Cr, Mo and W can be selected as single substance powders, and C can be selected as graphite powder.

[0017] Preferably, in step 2, the sintering time is 10 h to 15 h.

[0018] Preferably, in step 2, the diameter of the sintered blank is 18 mm to 20 mm.

[0019] Preferably, in step 3, the freezing time is 10 min to 15 min.

[0020] Preferably, in step 3, the diameter of the first rod is 7 mm to 9 mm.

[0021] Preferably, in step 4, the freezing time is 8 min to 12 min.

[0022] Preferably, in step 4, the diameter of the second rod is 2 mm to 4 mm.

[0023] Preferably, in step 5, the first annealing time is 32 min to 35 min.

[0024] Preferably, in step 5, the second annealing time is 12 min to 15 min.

[0025] The optimal two annealing times are beneficial to further improve the comprehensive properties of tungsten alloy filaments.

[0026] Preferably, in step 5, the water cooling condition is: water cooling to 20° C. to 35° C. to complete the second annealing.

[0027] Preferably, in step 6, the diameter of the tungsten alloy filament is 0.01 mm to 0.03 mm. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] Example 1

[0030] This embodiment provides a tungsten alloy filament, comprising the following components in percentage by mass: Cu: 1.8%, C: 0.12%, Ti: 0.5%, Cr: 0.7%, Mo: 7.5%, and the balance is W and unavoidable impurities;

[0031] The preparation method of the tungsten alloy filament comprises the following steps:

[0032] Step 1, Cu, C, Ti, Cr, Mo and W are uniformly mixed and pressed to obtain a green body;

[0033] Step 2, sintering the green compact at 1800° C. for 10 hours under an inert atmosphere to obtain a sintered compact with a diameter of 18 mm;

[0034] Step 3, performing a first rotary forging on the sintered blank at 1380° C., cooling to room temperature, and then freezing at −160° C. for 10 minutes to obtain a first rod with a diameter of 7 mm;

[0035] Step 4, performing a second rotary forging on the first rod at 1280° C., cooling to room temperature, and freezing at −110° C. for 8 minutes to obtain a second rod with a diameter of 4 mm;

[0036] Step 5, annealing the second rod at 1050° C. for 32 minutes to obtain a primary annealed rod; annealing the primary annealed rod at 700° C. for 12 minutes, and water cooling to 20° C. to obtain an annealed rod;

[0037] Step 6: Drawing the annealed rod to obtain tungsten alloy filaments.

[0038] Example 2

[0039] This embodiment provides a tungsten alloy filament, comprising the following components in percentage by mass: Cu: 2%, C: 0.1%, Ti: 0.8%, Cr: 0.9%, Mo: 5.5%, and the balance is W and unavoidable impurities;

[0040] The preparation method of the tungsten alloy filament comprises the following steps:

[0041] Step 1, Cu, C, Ti, Cr, Mo and W are uniformly mixed and pressed to obtain a green body;

[0042] Step 2, sintering the green compact at 2000° C. for 15 hours under an inert atmosphere to obtain a sintered compact with a diameter of 18 mm;

[0043] Step 3, performing a first rotary forging on the sintered blank at 1420° C., cooling to room temperature, and then freezing at −140° C. for 15 minutes to obtain a first rod with a diameter of 9 mm;

[0044] Step 4, performing a second rotary forging on the first rod at 1320° C., cooling to room temperature, and freezing at −130° C. for 12 minutes to obtain a second rod with a diameter of 2 mm;

[0045] Step 5, annealing the second rod at 950° C. for 35 minutes to obtain a primary annealed rod; annealing the primary annealed rod at 750° C. for 15 minutes, and water cooling to 35° C. to obtain an annealed rod;

[0046] Step 6: Drawing the annealed rod to obtain tungsten alloy filaments.

[0047] Example 3

[0048] This embodiment provides a tungsten alloy filament, comprising the following components in percentage by mass: Cu: 1.9%, C: 0.11%, Ti: 0.6%, Cr: 0.8%, Mo: 6.5%, and the balance is W and unavoidable impurities;

[0049] The preparation method of the tungsten alloy filament comprises the following steps:

[0050] Step 1, Cu, C, Ti, Cr, Mo and W are uniformly mixed and pressed to obtain a green body;

[0051] Step 2, sintering the green compact at 1900° C. for 12 hours under an inert atmosphere to obtain a sintered compact with a diameter of 19 mm;

[0052] Step 3, performing a first rotary forging on the sintered blank at 1400° C., cooling to room temperature, and then freezing at −150° C. for 12 minutes to obtain a first rod with a diameter of 8 mm;

[0053] Step 4, performing a second rotary forging on the first rod at 1300° C., cooling to room temperature and freezing at −120° C. for 10 min to obtain a second rod with a diameter of 3 mm;

[0054] Step 5, annealing the second rod at 1000° C. for 33 minutes to obtain a primary annealed rod; annealing the primary annealed rod at 720° C. for 13 minutes, and water cooling to 30° C. to obtain an annealed rod;

[0055] Step 6: Drawing the annealed rod to obtain tungsten alloy filaments.

[0056] Example 4

[0057] This embodiment provides a tungsten alloy filament, comprising the following components in percentage by mass: Cu: 1.8%, C: 0.1%, Ti: 0.7%, Cr: 0.9%, Mo: 6%, and the balance is W and unavoidable impurities;

[0058] The preparation method of the tungsten alloy filament comprises the following steps:

[0059] Step 1, Cu, C, Ti, Cr, Mo and W are uniformly mixed and pressed to obtain a green body;

[0060] Step 2, sintering the green compact at 1950° C. for 13 hours under an inert atmosphere to obtain a sintered compact with a diameter of 20 mm;

[0061] Step 3, performing a first rotary forging on the sintered blank at 1410° C., cooling to room temperature, and then freezing at −155° C. for 14 minutes to obtain a first rod with a diameter of 7.5 mm;

[0062] Step 4, performing a second rotary forging on the first rod at 1310° C., cooling to room temperature, and freezing at −125° C. for 9 minutes to obtain a second rod with a diameter of 4 mm;

[0063] Step 5, annealing the second rod at 1020° C. for 34 minutes to obtain a primary annealed rod; annealing the primary annealed rod at 740° C. for 15 minutes, and water cooling to 27° C. to obtain an annealed rod;

[0064] Step 6: Drawing the annealed rod to obtain tungsten alloy filaments.

[0065] Comparative Example 1

[0066] This comparative example provides a tungsten alloy filament, which is different from Example 1 in that:

[0067] The Ti in Example 1 is replaced by an equal amount of Cr;

[0068] The other ingredients and steps are the same as those in Example 1.

[0069] Comparative Example 2

[0070] This comparative example provides a tungsten alloy filament, which is different from Example 1 in that:

[0071] The Cr in Example 1 is replaced by an equal amount of Mo;

[0072] The other ingredients and steps are the same as those in Example 1.

[0073] Comparative Example 3

[0074] This comparative example provides a tungsten alloy filament, which is different from Example 1 in that:

[0075] The C in Example 1 is replaced by an equal amount of Ti;

[0076] The other ingredients and steps are the same as those in Example 1.

[0077] Comparative Example 4

[0078] This comparative example provides a tungsten alloy filament, which is different from Example 1 in that:

[0079] In step 4, the temperature during the second rotary forging is increased to 1450°C;

[0080] The other ingredients and steps are the same as those in Example 1.

[0081] Comparative Example 5

[0082] This comparative example provides a tungsten alloy filament, which is different from Example 1 in that:

[0083] Step 3, performing a first rotary forging on the sintered blank at 1380° C., and cooling to room temperature to obtain a first rod with a diameter of 7 mm;

[0084] Step 4, performing a second rotary forging on the first rod at 1280° C., and cooling to room temperature to obtain a second rod with a diameter of 4 mm;

[0085] The other ingredients and steps are the same as those in Example 1.

[0086] Comparative Example 6

[0087] This comparative example provides a tungsten alloy filament, which is different from Example 1 in that:

[0088] Step 5, annealing the second rod at 1050° C. for 32 minutes to obtain a primary annealed rod; annealing the primary annealed rod at 1150° C. for 12 minutes, and water cooling to 20° C. to obtain an annealed rod;

[0089] The other ingredients and steps are the same as those in Example 1.

[0090] Comparative Example 7

[0091] This comparative example provides a tungsten alloy filament, which is different from Example 1 in that:

[0092] Step 5, annealing the second rod at 1300° C. for 32 minutes to obtain a primary annealed rod; annealing the primary annealed rod at 700° C. for 12 minutes, and water cooling to 20° C. to obtain an annealed rod;

[0093] The other ingredients and steps are the same as those in Example 1.

[0094] Comparative Example 8

[0095] This comparative example provides a tungsten alloy filament, which is different from Example 1 in that:

[0096] Step 5, annealing the second rod at 1050° C. for 32 minutes to obtain a primary annealed rod; annealing the primary annealed rod at 700° C. for 12 minutes to obtain an annealed rod;

[0097] The other ingredients and steps are the same as those in Example 1.

[0098] The elongation and tensile strength of the tungsten alloy filaments prepared in Examples 1 to 4 and Comparative Examples 1 to 8 were tested, wherein the tensile strength test was in accordance with GB / T 23272-2009 and the elongation test was in accordance with GB / T10573-2020. The specific test results are shown in Table 1:

[0099] Table 1

[0100] Test items <![CDATA[Tensile strength (N / mm 2 )]]> Total elongation at break (%) Example 1 4310 4.3 Example 2 4250 4.1 Example 3 4360 3.9 Example 4 4290 4.4 Comparative Example 1 3717 2.5 Comparative Example 2 4030 1.9 Comparative Example 3 3520 3.5 Comparative Example 4 3620 2.3 Comparative Example 5 3320 2.4 Comparative Example 6 3420 2.1 Comparative Example 7 3250 3.5 Comparative Example 8 3462 1.6

[0101] The present invention reasonably controls the added elements and the added amount in the tungsten alloy, and the elements are compositely strengthened, so that the tungsten alloy filament provided by the present invention has excellent ductility and strength, and its tensile strength reaches 4360N / mm 2 , the total elongation at break increased to 4.3%.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A tungsten alloy filament, characterized in that: The invention comprises the following components in percentage by mass: Cu: 1.8%-2%, C: 0.1%-0.12%, Ti: 0.5%-0.8%, Cr: 0.7%-0.9%, Mo: 5.5%-7.5%, and the balance is W and unavoidable impurities.

2. A method for preparing the tungsten alloy filament according to claim 1, characterized in that: The steps include: Step 1, Cu, C, Ti, Cr, Mo and W are uniformly mixed and pressed to obtain a green body; Step 2, sintering the green compact at 1800° C. to 2000° C. in an inert atmosphere to obtain a sintered compact; Step 3, performing a first rotary forging on the sintered blank at 1380° C. to 1420° C., cooling to room temperature, and then freezing at -160° C. to -140° C. to obtain a first rod; Step 4, performing a second rotary forging on the first rod at 1280° C. to 1320° C., cooling to room temperature and then freezing at -130° C. to -110° C. to obtain a second rod; Step 5, performing a first annealing on the second rod at 950° C. to 1050° C. to obtain a primary annealed rod; performing a second annealing on the primary annealed rod at 700° C. to 750° C., and water cooling to obtain an annealed rod; Step 6: Drawing the annealed rod to obtain tungsten alloy filaments.

3. The method for preparing tungsten alloy filaments according to claim 2, characterized in that: In step 2, the sintering time is 10h to 15h; and / or In step 2, the diameter of the sintered blank is 18 mm to 20 mm.

4. The method for preparing tungsten alloy filaments according to claim 2, characterized in that: In step 3, the freezing time is 10 min to 15 min; and / or In step 3, the diameter of the first rod is 7 mm to 9 mm.

5. The method for preparing tungsten alloy filaments according to claim 2, characterized in that: In step 4, the freezing time is 8 minutes to 12 minutes.

6. The method for preparing tungsten alloy filaments according to claim 2, characterized in that: In step 4, the diameter of the second rod is 2 mm to 4 mm.

7. The method for preparing tungsten alloy filaments according to claim 2, characterized in that: In step 5, the first annealing time is 32 minutes to 35 minutes.

8. The method for preparing tungsten alloy filaments according to claim 2, characterized in that: In step 5, the second annealing time is 12 min to 15 min.

9. The method for preparing tungsten alloy filaments according to claim 2, characterized in that: In step 5, the water cooling condition is: water cooling to 20° C. to 35° C. to complete the second annealing.

10. The method for preparing tungsten alloy filaments according to claim 2, characterized in that: In step 6, the diameter of the tungsten alloy filament is 0.01 mm to 0.03 mm.