Hydrogenated titanium alloy injection feed and preparation method thereof

Abstract

The present invention provides a hydrogenated titanium alloy injection feedstock comprising the following components by weight: 77-80% hydrogenated titanium alloy powder, 16-19% polyoxymethylene, 3-4% skeleton agent, 0.4-1% lubricant, and 0.1-0.5% antioxidant. The present invention also provides a method for preparing the hydrogenated titanium alloy injection feedstock. The feedstock of the present invention utilizes hydrogenated titanium alloy powder as its primary component, reducing preparation costs. By carefully combining the various components in the feedstock, the feedstock overcomes the poor fluidity of hydrogenated titanium alloys due to powder irregularities, ensuring that the overall mechanical properties of the formed parts are comparable to those of parts formed from expensive spherical powders.

Description

Technical Field

[0001] The present invention relates to the technical field of titanium alloy powder injection molding, in particular to a hydrogenated titanium alloy injection feed and a preparation method thereof. Background Art

[0002] Titanium and titanium alloys have attracted widespread attention in the fields of aerospace, weapons and equipment, transportation, electronic equipment, etc. due to their light weight, high specific strength, good corrosion resistance and non-magnetic properties. Combined with the unique advantages of metal powder injection molding technology in the forming of parts with precise dimensions and complex structures, it has effectively avoided the inherent defects of titanium alloys such as difficult processing and low processing efficiency, allowing titanium alloy powder injection molding products to quickly enter the consumer field that requires lightweight and good corrosion resistance.

[0003] The development of titanium alloy injection molding technology has been relatively slow compared to materials such as stainless steel, copper alloy, and tungsten alloy. The main reasons are the high price of titanium alloy powder raw materials, the difficulty in controlling the powder-binder ratio in the feed, and the difficulty in selecting the type and combination of binders. In addition, the microstructure of sintered samples of duplex titanium alloys (such as TC4) is characterized by typical Widmanstätten structure. Its strength and plasticity are inferior to those of other structures (equiaxed, duplex, and basketweave). In addition, the presence of a certain amount of porosity in injection molded products further reduces the mechanical properties of titanium alloy injection molded samples.

[0004] Chinese Patent Publication No. CN113333752 A discloses a feedstock product for titanium and titanium alloy injection molding and its preparation method. This feedstock utilizes inexpensive and easy-to-prepare TiH2 powder as the raw material, which indeed reduces feedstock costs from the powder itself. However, mixing TiH2 powder with other master alloy powders can lead to problems such as macrosegregation of elements and uneven micro-component distribution when preparing titanium alloy products or specimens. Furthermore, while this feedstock utilizes a water-soluble binder during degreasing, while it can avoid some environmental pollution associated with solvent degreasing, the degreasing process suffers from poor conformability of the degreased blank. This is particularly true for thin-walled titanium alloy parts, which are typically manufactured using injection molding technology to improve yield. Degreasing with a water-soluble binder can easily result in defects such as collapse and cracking.

[0005] Therefore, a new titanium and titanium alloy feed material is needed that can reduce costs while ensuring that the comprehensive mechanical properties of the formed parts meet the requirements. Summary of the Invention

[0006] The purpose of the present invention is to address the shortcomings of existing feed preparation technology and provide a hydrogenated titanium alloy injection feed and a preparation method thereof. The use of hydrogenated titanium alloy powder reduces the preparation cost, and through the combination of the various components in the feed, overcomes the defect of poor fluidity of hydrogenated titanium alloy caused by powder irregularity, thereby ensuring that the comprehensive mechanical properties of the formed parts are comparable to those of expensive spherical powder formed parts.

[0007] The first aspect of the present invention relates to a hydrogenated titanium alloy injection feed, comprising the following components in mass percentage: 77-80% hydrogenated titanium alloy powder, 16-19% polyoxymethylene, 3-4% skeleton agent, 0.4-1% lubricant, and 0.1-0.5% antioxidant.

[0008] In an optional embodiment, the particle size D of the hydrogenated titanium alloy powder is 90 ≤50μm, sphericity ≥90, tap density ≥2.3g / cm 3 , hydrogen content ≥ 0.1wt.%; the hydrogenated titanium alloy is hydrogenated TC4.

[0009] In an alternative embodiment, the antioxidant is benzotriazole (BTA).

[0010] In an optional embodiment, the skeleton agent is a mixture of one or more of high-density polyethylene, ethylene acrylic acid copolymer and vinyl bisstearamide.

[0011] In an optional embodiment, the lubricant is stearic acid or paraffin.

[0012] In an optional embodiment, the particle size of the hydrogenated titanium alloy injection feed is 2 to 4 mm.

[0013] A second aspect of the present invention relates to a method for preparing the aforementioned hydrogenated titanium alloy injection feed, comprising the following steps:

[0014] S1. Mixing

[0015] Seal the mixing chamber of the mixer, adjust the mixing chamber to the required mixing conditions, preheat the mixing tank to a first temperature range, add the hydrogenated titanium alloy powder and the antioxidant into the preheated mixing tank at the same time and perform the first mixing to obtain a first mixed material;

[0016] After heating the mixing tank to a second temperature range, polyoxymethylene is added to the first mixture, and mixing is performed for a second time to obtain a second mixture;

[0017] After heating the mixing tank to the third temperature range, adding the skeleton agent and the lubricant to the second mixture, and performing the third mixing to obtain the third mixture;

[0018] S2, granulation

[0019] The third mixed material is granulated to obtain the hydrogenated titanium alloy injection feed.

[0020] In an optional embodiment, the mixing chamber is flushed with argon at a pressure of 0.5 MPa and a flow rate of 20 L / min to maintain the oxygen content below 1000 ppm and adjust to the desired mixing conditions.

[0021] In an optional embodiment, the first temperature range is [135°C, 145°C], the first mixing time is 20-25 min, and the screw speed is 6-8 rpm;

[0022] The second temperature range is [160°C, 170°C], the second mixing time is 10-15 minutes, and the screw speed is 10-12 rpm;

[0023] The third temperature range is [175°C, 185°C], the second mixing time is 60-70 min, and the screw speed is 15-25 rpm.

[0024] In an alternative embodiment, the granulation process is as follows:

[0025] The third mixed material is transferred into a granulator, with argon at a pressure of 0.5 MPa as the protective gas, the screw speed in the granulator is 10-15 rpm, the extrusion die is preheated to 150-160°C, and the cutting speed is 750-780 rpm to obtain the hydrogenated titanium alloy injection feed.

[0026] Compared with the prior art, the present invention has the following significant beneficial effects:

[0027] The present invention successfully prepares hydrogenated titanium alloy injection feed using low-cost hydrogenated pre-alloyed TC4 powder, which reduces costs while ensuring that the comprehensive mechanical properties of the formed parts are comparable to those of expensive spherical powder formed parts, meeting usage requirements.

[0028] Compared with mechanically alloyed powder, the use of pre-alloyed powder has the advantage of uniform distribution of alloy elements, which reduces the risk of uneven mechanical properties and dimensional shrinkage of sintered samples. At the same time, the introduction of hydrogen element during the powder sintering process can achieve the effect of grain refinement compared to atomized powder, thereby improving the mechanical properties of metal injection molded parts.

[0029] By adding polyformaldehyde with thermoplastic low molecular chains, the powder can be greatly helped to improve its fluidity at a certain temperature, thereby improving the filling properties of the feed; polyformaldehyde is combined with a small amount of high-temperature skeleton agent with a large molecular chain, combined with the good shape retention characteristics of the powder due to its irregular shape. After catalytic degreasing of the injection blank, the degreased blank can maintain a high dimensional accuracy, good shape and a certain strength, which helps to prevent defects such as collapse and deformation during transfer.

[0030] The addition of lubricant improves the wettability between irregular powder and polyformaldehyde and skeleton agent, helps the binder to fully and completely wrap the powder surface, and avoids powder agglomeration.

[0031] The addition of the antioxidant BTA has two functions: first, it covers the powder surface to inhibit oxygen, and second, it prevents the high-temperature decomposition products of the polymer binder from corroding the titanium alloy powder. Furthermore, the addition reaction between BTA and polyoxymethylene prevents the hydrogen atoms in BTA from escaping the binder, thus maintaining a neutral binder environment. This overcomes BTA's weak acidity in water and reduces the pungent odor caused by BTA. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a physical diagram of the feed obtained in Example 1 of the present invention.

[0033] Figure 2 1 is a SEM image of the hydrogenated TC4 powder used in Example 1 of the present invention.

[0034] Figure 3 1 is a SEM image of the feed fracture obtained in Example 1 of the present invention.

[0035] Figure 4 This is a metallographic diagram of sample 1 according to the present invention. DETAILED DESCRIPTION

[0036] In order to better understand the technical content of the present invention, specific embodiments are given and described below with reference to the accompanying drawings.

[0037] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to be comprehensive. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, can be implemented in any of a number of ways.

[0038] By introducing hydrogen into titanium alloy, the morphology, phase size and phase distribution of the alloy can be improved, thereby improving the mechanical properties of the titanium alloy.

[0039] In addition, the O element content has a significant effect on the mechanical properties of titanium alloys. The strength of titanium alloys will increase with the increase of O content, while the plasticity will decrease with the increase. Therefore, effectively controlling the increase of O content in the feeding preparation process can control the mechanical properties of the formed parts.

[0040] Based on this, the present invention aims to use hydrogenated titanium alloy powder as the primary feedstock component to improve the mechanical properties of metal injection molded parts. Hydrogenated titanium alloy is inexpensive, and the feedstock production cost is nearly one-third lower than that of aerosolized powders. However, due to mechanical crushing, hydrogenated titanium alloy powders have an irregular shape and poor flowability, making them difficult to use as a feedstock.

[0041] Therefore, further, the present invention overcomes the defect of poor fluidity of hydrogenated titanium alloy powder and effectively reduces oxygen increment by optimizing the feed formula while using hydrogenated titanium alloy powder as the main component of the feed.

[0042] In an exemplary embodiment of the present invention, a hydrogenated titanium alloy injection feed is provided, comprising the following components in mass percentage: 77-80% hydrogenated titanium alloy powder, 16-19% polyformaldehyde, 3-4% skeleton agent, 0.4-1% lubricant, and 0.1-0.5% antioxidant.

[0043] In an optional embodiment, the particle size D of the hydrogenated titanium alloy powder is 90 ≤50μm, sphericity ≥90, tap density ≥2.3g / cm 3 , hydrogen content ≥ 0.1wt.%; the hydrogenated titanium alloy is hydrogenated TC4.

[0044] It is understandable that the acquisition of hydrogenated titanium alloy powder is a prior art and can be prepared by common means in the art or directly purchased.

[0045] In an optional embodiment, the antioxidant is benzotriazole (BTA); BTA can form covalent bonds and coordination bonds with Ti atoms to generate chain polymers, which can form a protective film on the surface of hydrogenated TC4, hindering the redox reaction of the alloy, preventing the corrosion of TC4 and also inhibiting the adsorption of oxygen atoms; in addition, BTA can undergo an addition reaction with polyformaldehyde, so that the H atoms in BTA cannot be separated from the binder, thereby keeping the entire binder environment in a neutral state, and at the same time, the derivatives obtained by the reaction also alleviate the irritating odor caused by BTA.

[0046] In an optional embodiment, the skeleton agent is a mixture of one or more of high-density polyethylene, ethylene acrylic acid copolymer and vinyl bisstearamide.

[0047] It should be understood that when a mixture of two or three skeleton agents is used, they can be mixed in any proportion and are not further limited herein.

[0048] In an alternative embodiment, the lubricant is stearic acid or paraffin.

[0049] In an optional embodiment, the particle size of the hydrogenated titanium alloy injection feed is 2 to 4 mm.

[0050] The feed material of the polyaldehyde-based system of the present invention has the characteristics of low apparent viscosity, good filling property, high degreasing efficiency, easy removal of binder, low environmental pollution, excellent green body shape retention, and easy transfer.

[0051] In another exemplary embodiment of the present invention, a method for preparing the aforementioned hydrogenated titanium alloy injection feed is also provided, comprising the following steps:

[0052] S1. Mixing

[0053] The mixing chamber of the mixer is sealed, the mixing chamber is adjusted to the required mixing conditions, and the mixing tank is preheated to a first temperature range. The hydrogenated titanium alloy powder and the antioxidant are added to the preheated mixing tank at the same time and mixed for the first time to obtain a first mixture.

[0054] After the mixing tank is heated to the second temperature range, polyoxymethylene is added to the first mixed material, and the mixed material is mixed for the second time to obtain the second mixed material.

[0055] After the mixing tank is heated to the third temperature range, a skeleton agent and a lubricant are added to the second mixed material, and the mixing is performed for the third time to obtain a third mixed material.

[0056] S2, granulation

[0057] The third mixed material is granulated to obtain the hydrogenated titanium alloy injection feed.

[0058] The antioxidant benzotriazole (BTA) is added simultaneously with the hydrogenated titanium alloy powder to effectively wrap the powder to prevent the powder from being oxidized. At the same time, it can also improve the antioxidant capacity of other polymer binder materials and further reduce the oxygen increment.

[0059] In an optional embodiment, the mixing chamber is flushed with argon at a pressure of 0.5 MPa and a flow rate of 20 L / min to maintain the oxygen content below 1000 ppm and adjust to the desired mixing conditions.

[0060] In an optional embodiment, the first temperature range is [135° C., 145° C.], the first mixing time is 20 to 25 minutes, and the screw speed is 6 to 8 rpm.

[0061] The second temperature range is [160°C, 170°C], the second mixing time is 10-15 minutes, and the screw speed is 10-12 rpm.

[0062] The third temperature range is [175°C, 185°C], the second mixing time is 60-70 min, and the screw speed is 15-25 rpm.

[0063] In an alternative embodiment, the granulation process is as follows:

[0064] The third mixed material is transferred into a granulator, with argon at a pressure of 0.5 MPa as the protective gas, the screw speed in the granulator is 10-15 rpm, the extrusion die is preheated to 150-160°C, and the cutting speed is 750-780 rpm to obtain the hydrogenated titanium alloy injection feed.

[0065] In order to make the purpose and advantages of the feed preparation scheme more clear, the embodiments of the present invention are described in further detail below.

[0066] Example 1

[0067] 1. Set the particle size to 40μm≤D 90 ≤60μm, 90≤sphericity≤95, 2.3g / cm 3 ≤Tap density≤2.6g / cm 3 TC4 powder with hydrogen content of 0.1 wt.% ≤ 0.5 wt.% (see Table 1 for specific powder composition) was placed in an electronic oven, set at 70°C, and kept warm for 2-3 hours.

[0068] Table 1 Element composition of hydrogenated TC4 powder alloy (wt.%)

[0069]

[0070] Take 5.43 kg of dried powder, 1.35 kg of polyoxymethylene, 0.18 kg of high-density polyethylene as a skeleton agent, 0.032 kg of stearic acid as a lubricant, and 0.008 kg of BTA as an antioxidant.

[0071] 2. Put all the weighed raw materials into the mixer, seal the mixer, and introduce argon gas with a pressure of 0.5 MPa and a flow rate of 20 L / min to purge the mixing chamber. At the same time, set the temperature of the mixing tank to 145°C for preheating. When the temperature reaches 145°C and the oxygen content in the mixing chamber is stably lower than 1000 ppm, put the hydrogenated TC4 powder and BTA into the mixing tank at the same time for stirring and preheating. The screw speed is 6 rpm and mixing is carried out for 20 minutes.

[0072] Then set the temperature to 165°C, add polyoxymethylene, lower the ram, set the screw speed to 12 rpm, and mix for 15 minutes.

[0073] The temperature was raised to 180°C, the skeleton agent and lubricant were added, the ram was lowered, the screw speed was 20 rpm, and mixing was carried out for 60 minutes. During this process, the die head temperature in the granulator was set to 150°C and preheated.

[0074] 3. Quickly transfer the mixed material into the pelletizer, use argon with a pressure of 0.5 MPa as the protective gas, set the speed of the feed screw in the pelletizer to 10 rpm, and the cutting speed to 750 rpm to produce about 6.5 kg of feed with a size of about 2-4 mm.

[0075] Comparative Example 1

[0076] No added antioxidant BTA

[0077] 1. Set the particle size to 40μm≤D 90 ≤60μm, 90≤sphericity≤95, 2.3g / cm 3 ≤Tap density≤2.6g / cm 3 TC4 powder with hydrogen content of 0.1 wt.% ≤ 0.5 wt.% (see Table 1 for specific powder composition) was placed in an electronic oven, set at 70°C, and kept warm for 2-3 hours.

[0078] Take 5.43 kg of dried powder, 1.35 kg of polyoxymethylene, 0.18 kg of high-density polyethylene as a skeleton agent, and 0.04 kg of stearic acid as a lubricant.

[0079] 2. Put all the weighed raw materials into the mixer, seal the mixer, and introduce argon gas with a pressure of 0.5 MPa and a flow rate of 20 L / min to purge the mixing chamber. At the same time, set the temperature of the mixing tank to 145°C for preheating. When the temperature reaches 145°C and the oxygen content in the mixing chamber is stably lower than 1000 ppm, put the hydrogenated TC4 powder into the mixing tank for stirring and preheating. The screw speed is 6 rpm and the mixing is carried out for 20 minutes.

[0080] Then set the temperature to 165°C, add polyoxymethylene, lower the ram, set the screw speed to 12 rpm, and mix for 15 minutes.

[0081] The temperature was raised to 180°C, the skeleton agent and lubricant were added, the ram was lowered, the screw speed was 20 rpm, and mixing was carried out for 60 minutes. During this process, the die head temperature in the granulator was set to 150°C and preheated.

[0082] 3. Quickly transfer the mixed material into the pelletizer, use argon with a pressure of 0.5 MPa as the protective gas, set the speed of the feed screw in the pelletizer to 10 rpm, and the cutting speed to 750 rpm to produce about 6.5 kg of feed with a size of about 2-4 mm.

[0083] Comparative Example 2

[0084] Using aerosolized TC4 powder with the same particle size range

[0085] 1. Set the particle size to 40μm≤D90 ≤60μm, 95≤sphericity≤97, 2.7g / cm 3 ≤Tap density≤2.9g / cm 3 The atomized TC4 powder was placed in an electronic oven. The specific powder composition is shown in Table 2.

[0086] Table 2 Elemental composition of gas atomized TC4 powder alloy (wt.%)

[0087]

[0088]

[0089] Take 5.78 kg of dried powder, 1.05 kg of polyoxymethylene, 0.14 kg of high-density polyethylene as a skeleton agent, 0.024 kg of stearic acid as a lubricant, and 0.006 kg of BTA as an antioxidant.

[0090] 2. Put all the weighed raw materials into the mixer, seal the mixer, and introduce argon gas with a pressure of 0.5 MPa and a flow rate of 20 L / min to purge the mixing chamber. At the same time, set the temperature of the mixing tank to 145°C for preheating. When the temperature reaches 145°C and the oxygen content in the mixing chamber is stably lower than 1000 ppm, put the hydrogenated TC4 powder and BTA into the mixing tank at the same time for stirring and preheating. The screw speed is 6 rpm and mixing is carried out for 20 minutes.

[0091] Then set the temperature to 165°C, add polyoxymethylene, lower the ram, set the screw speed to 12 rpm, and mix for 15 minutes.

[0092] The temperature was raised to 180°C, the skeleton agent and lubricant were added, the ram was lowered, the screw speed was 20 rpm, and mixing was carried out for 60 minutes. During this process, the die head temperature in the granulator was set to 150°C and preheated.

[0093] 3. Quickly transfer the mixed material into the granulator, use argon with a pressure of 0.5 MPa as the protective gas, set the speed of the feed screw in the granulator to 10 rpm, and the cutting speed to 750 rpm to obtain a feed of about 2-4 mm.

[0094] Injection molding, debinding and sintering

[0095] The feeding injection molding, degreasing and sintering of Example 1 and Comparative Examples 1-2 were used to obtain sintered samples, namely Sample 1, Sample 2 and Sample 3.

[0096] An injection molding machine is used for injection molding, and the injection pressure, temperature, injection speed, and holding pressure are set to 1200 MPa, 190°C, 30 mm / s, and 1100 MPa.

[0097] The injection molded parts were transferred into a debinding furnace and catalytically debinded using oxalic acid. The debinding temperature was set at 140°C and the debinding time was set at 5 h.

[0098] The degreased blank was transferred into a metal vacuum sintering furnace, and the sintering temperature was set to 1150°C and the sintering time was set to 2.5 h.

[0099] Characterization

[0100] like Figure 1 The feed obtained in Example 1 shown has a smooth surface, no obvious separation between the hydrogenated powder and the binder, and the feed particle size is basically maintained at 2-4 mm.

[0101] from Figure 2 It can be seen that the hydrogenated TC4 powder has an irregular shape, and its fluidity and tap density are worse than those of the aerosolized spherical powder.

[0102] from Figure 3 It can be seen from the SEM image of the feed fracture obtained in Example 1 that the binder in the feed well wraps the hydrogenated powder, which is beneficial to the injection molding process of the sample. At the same time, there are no obvious holes in the feed and it has a very high density, which is a necessary condition for the low porosity of the sintered sample.

[0103] from Figure 4 It can be seen from the metallographic image of the feed obtained in Example 1 that the porosity is low. Although most of the microstructure is lamellar α phase, the thickness of the lamellar layer is very small. It can be considered that the H element plays a role in grain refinement and strengthening during the sintering process; there is a small amount of equiaxed α phase in the microstructure, which is beneficial to the improvement of the plasticity of the alloy. The combined effects of grain refinement and equiaxion improve the comprehensive mechanical properties of the metal injection molded titanium alloy and improve the strength and toughness matching of the titanium alloy.

[0104] From the above, it can be seen that the present invention successfully prepares hydrogenated titanium alloy injection feed.

[0105] Sintered sample alloy element content test

[0106] The alloying element contents of samples 1-3 were tested, and the results are shown in Table 3.

[0107] Table 3 Alloying element contents in sintered samples of Examples and Comparative Examples (wt.%)

[0108]

[0109] As can be seen from Table 3, the oxygen increase in Samples 1 and 3 is approximately 0.12wt.%, while the oxygen increase in Sample 2 is 0.17wt.%. It can be seen that after adding BTA, the oxygen increase is well inhibited during the injection molding process of the titanium alloy, thereby effectively improving the plasticity of the metal injection molded titanium alloy.

[0110] Mechanical properties

[0111] The mechanical properties of samples 1-3 were tested, and the results are shown in Table 4.

[0112] Table 4 Comparison of mechanical properties of sintered samples of Example and Comparative Example

[0113]

[0114] From the performance in Table 4, it can be seen that although the strength of sample 1 is poorer than that of sample 2, the plasticity is improved. This confirms that under the same metal injection molding conditions, the addition of BTA can improve the comprehensive mechanical properties of metal injection molded titanium alloy and improve the strength-toughness matching of titanium alloy.

[0115] Compared with sample 3, the strength of sample 1 is almost the same as that of sample 3, and the plasticity can reach more than half of that of sample 3. Although the strength and plasticity are slightly worse, the comprehensive mechanical properties of sample 1 fully meet the requirements of GB / T 38981-2020. From the perspective of comprehensive mechanical properties and cost considerations (the cost of hydrogenated powder is only one-third of that of aerosol powder), hydrogenated powder can partially replace aerosol powder to prepare metal injection molded titanium alloys.

[0116] From the above, it can be seen that the titanium alloy structural parts, non-load-bearing parts and corrosion-resistant parts produced by the feed injection molding of the present invention can fully meet daily needs. This move will strongly promote titanium alloy MIM products to quickly occupy the lightweight application market.

[0117] While the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A method for preparing a hydrogenated titanium alloy injection feed, characterized in that: The following steps are involved: S1. Mixing The mixing chamber of the mixer is sealed, the mixing chamber is adjusted to the desired mixing conditions, and the mixing tank is preheated to a first temperature range. The hydrogenated titanium alloy powder and the antioxidant are simultaneously added to the preheated mixing tank and mixed for the first time to obtain a first mixture; wherein the first temperature range is [135°C, 145°C], the first mixing time is 20-25 minutes, and the screw speed is 6-8 rpm; After heating the mixing tank to a second temperature range, polyoxymethylene is added to the first mixture, and a second mixing is performed to obtain a second mixture; wherein the second temperature range is [160°C, 170°C], the second mixing time is 10-15 minutes, and the screw speed is 10-12 rpm; After heating the mixing tank to the third temperature range, a skeleton agent and a lubricant are added to the second mixture, and the mixture is mixed for the third time to obtain a third mixture; wherein the third temperature range is [175°C, 185°C], the third mixing time is 60-70 minutes, and the screw speed is 15-25 rpm; S2, granulation Granulating the third mixed material to obtain the hydrogenated titanium alloy injection feed; The hydrogenated titanium alloy injection feed comprises the following components in percentage by mass: 77-80% hydrogenated titanium alloy powder, 16-19% polyoxymethylene, 3-4% skeleton agent, 0.4-1% lubricant, and 0.1-0.5% antioxidant; the antioxidant is benzotriazole.

2. The preparation method according to claim 1, characterized in that The mixing chamber was flushed with argon at a pressure of 0.5 MPa and a flow rate of 20 L / min to keep the oxygen content below 1000 ppm and adjust to the required mixing conditions.

3. The preparation method according to claim 1, characterized in that The granulation process is as follows: The third mixture is transferred into a granulator, with argon at a pressure of 0.5 MPa as the protective gas, the screw speed in the granulator is 10-15 rpm, the extrusion die is preheated to 150-160°C, and the cutting speed is 750-780 rpm to obtain the hydrogenated titanium alloy injection feed.

4. The preparation method according to claim 1, characterized in that Particle size D of hydrogenated titanium alloy powder 90 ≤50μm, sphericity ≥90, tap density ≥2.3g / cm 3 , hydrogen content ≥0.1wt.%; the hydrogenated titanium alloy is hydrogenated TC4.

5. The preparation method according to claim 1, characterized in that The skeleton agent is a mixture of one or more of high-density polyethylene, ethylene acrylic acid copolymer and vinyl bisstearamide.

6. The preparation method according to claim 1, characterized in that The lubricant is stearic acid or paraffin.

7. The preparation method according to any one of claims 1 to 6, characterized in that The particle size of the hydrogenated titanium alloy injection feed is 2-4 mm.

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