Particle-mesh composite reinforced titanium-aluminum-based composite material and preparation method thereof

Abstract

The invention provides a particle-net-shaped composite reinforced titanium-aluminum-based composite material and a preparation method, and belongs to the technical field of metal additive manufacturing. The composite material is composed of a reinforcing phase and a matrix phase, the reinforcing phase comprises Ti5Si3, the matrix phase comprises a titanium-aluminum alloy, one part of Ti5Si3 in the reinforcing phase is distributed in a net structure, and the other part of Ti5Si3 in the reinforcing phase is distributed in a granular dispersion mode. The preparation method comprises the following steps: preparing raw material powder according to the volume ratio of Ti6Al4V powder to AlSi10Mg powder of (5.5-6.5): (4.5-3.5), and uniformly mixing; standby powder is obtained; dried standby powder is used as a treatment object, a laser printing technology is adopted for preparing the particle-net composite reinforced titanium-aluminum-based composite material, and during printing, the laser power is controlled to be 350-610 W; and the scanning speed is 360 to 480 mm / min. The material is scientific in structural design, the process is simple and controllable, and the obtained product is extremely excellent in wear resistance and convenient for industrial application.

Description

Technical Field

[0001] The invention provides a particle-net composite reinforced titanium-aluminum based composite material and a preparation method thereof, belonging to the technical field of metal additive manufacturing. Background Art

[0002] Titanium alloy has excellent properties such as high specific strength, low density, and good biocompatibility, and has broad application prospects in aerospace, biomedicine and other fields. However, its low hardness and poor friction and wear properties limit its service application in severe wear environments. Studies have shown that titanium-aluminum-based composite coatings can effectively improve the wear resistance of titanium alloy surfaces. As the service environment becomes increasingly severe, the uniform distribution of traditional reinforcement phases is difficult to meet performance requirements, and microstructure optimization design is an effective way to further improve the performance of titanium-aluminum-based composites.

[0003] In recent years, metal-based composite materials with in-situ synthesized reinforcement phases in a three-dimensional network distribution have gradually attracted the attention of scientific researchers. The currently commonly used methods for preparing titanium-aluminum-based composite coatings mainly include thermal spraying, cold spraying, chemical vapor deposition, laser directed energy deposition, etc. Compared with other methods, the laser directed energy deposition technology has a simple process flow and a safe operation process. Existing studies often use external reinforcement phases to strengthen titanium-aluminum alloys. However, due to the small number of slip systems and poor room temperature plasticity of titanium-aluminum alloys, as well as the poor wettability and large difference in linear expansion coefficient between the external reinforcement phase and the alloy, cracking is prone to occur during the rapid solidification laser deposition process. At the same time, different laser process parameters and raw material powder ratios will also cause differentiation in the organization of laser additively manufactured titanium-aluminum-based composites, resulting in uncontrollable structure. For example, the typical Ti-Al-Si alloy mainly presents a structure of Ti in laser additive manufacturing. 5 Si 3 The reinforcement phase is dispersed in the titanium aluminum matrix. In existing research (such as patent 2020108391649), Ti 5 Si 3 The reinforcement phase is distributed in the titanium aluminum matrix in a network shape, resulting in a product with excellent high-temperature mechanical properties. Summary of the invention

[0004] Based on Patent 2020108391649, in order to obtain products with excellent wear resistance, the present invention proposes a design concept of composite reinforcement using particle + mesh reinforcement to reinforce titanium-aluminum-based composite materials and develops a preparation process that matches it.

[0005] The present invention discloses a particle-net composite reinforced titanium-aluminum-based composite material, which is composed of a reinforcement phase and a matrix phase, wherein the reinforcement phase includes Ti 5 Si 3 , the matrix phase includes titanium aluminum alloy, and the reinforcement phase includes Ti 5Si 3 Part of it is distributed in a network structure, and part of it is dispersed in a granular manner, including part of it being distributed in a granular manner in the network structure; Ti dispersed in a granular manner 5 Si 3 Phase, its size includes nano size, micro-nano size, etc.

[0006] The present invention discloses a particle-net composite reinforced titanium-aluminum-based composite material, wherein the particle-net composite reinforced titanium-aluminum-based composite material is dispersedly distributed with nano-Ti 5 Si 3 Particles.

[0007] The present invention discloses a particle-net composite reinforced titanium-aluminum-based composite material, wherein the reinforcing phase is Ti generated in situ. 5 Si 3 .

[0008] The present invention discloses a particle-net composite reinforced titanium-aluminum-based composite material, wherein the matrix phase is Ti 3 Al phase.

[0009] The present invention discloses a particle-net composite reinforced titanium-aluminum-based composite material, wherein the Ti 5 Si 3 One part is distributed in a continuous network structure, and the other part is dispersed in the network structure in a granular form.

[0010] Preferably, in the reinforcement phase dispersed in the matrix and on the surface of the matrix in a particle form, at least one particle is connected to the reinforcement phase distributed in a network structure to form a network.

[0011] Preferably, the reinforcement phase is generated in-situ during the laser additive manufacturing process.

[0012] The present invention provides a method for preparing a particle-net composite reinforced titanium-aluminum-based composite material, comprising the following steps: Step 1 Using Ti6Al4V powder and AlSi10Mg powder as raw materials, Ti6Al4V powder and AlSi10Mg powder are prepared in a volume ratio of 5.5-6.5:4.5-3.5, preferably 6:4, and then the prepared powders are evenly mixed to obtain a standby powder; Step 2 The dry reserve powder was used as the processing object, and the particle-net composite reinforced titanium-aluminum matrix composite material was prepared by laser printing process. The laser printing was controlled as follows: The laser power is 350-610W; the laser scanning speed is 360-480mm / min.

[0013] When used in industry, Ti6Al4V powder and AlSi10Mg powder weighed in the designed proportion are mechanically mixed in a three-dimensional mixer to obtain a mixed powder, and the mixed powder is placed in a vacuum drying oven and kept at 60°C for 2 hours to obtain a dry standby powder. In order to reduce the moisture and residual oxygen content of the powder, the dry standby powder is placed in a vacuum bag and vacuum-packed for standby use during storage.

[0014] In order to further improve the printing quality, the substrate can be rinsed with clean water, then placed in anhydrous ethanol for ultrasonic cleaning for 5 minutes, and then dried for use. The material of the substrate can be titanium alloy or pure titanium.

[0015] The particle size range of Ti6Al4V powder is 53~105um, and the particle size range of AlSi10Mg powder is 50~150um.

[0016] Preferably, the substrate heating temperature is room temperature-300°C, including 100-300°C.

[0017] Furthermore, during laser printing, the laser power is controlled to be 470-510 W, the laser scanning speed is controlled to be 410-480 mm / min, and the substrate heating temperature is controlled to be 190-300° C.

[0018] As a further preference, during laser printing, the laser power is controlled to be 475-500 W, the laser scanning speed is 420-480 mm / min; and the substrate heating temperature is 200-300°C.

[0019] It has the following advantages: The present invention adopts laser deposition technology, and by adjusting the laser power, scanning speed, and substrate preheating temperature, a reinforcement phase is obtained that is partially distributed in a continuous network structure and partially dispersed in the network structure in a granular form, which provides the necessary conditions for obtaining a titanium-aluminum-based composite material with high hardness and wear resistance. The hardness of the printed product obtained by the present invention after optimization reaches 760.2HV, and the wear rate is as low as 1.11×10 -4 mm 3 / Nm. The preparation process of the present invention is simple, efficient and has significant effect.

[0020] A three-dimensional mixer was used to fully mix the Ti6Al4V powder and the AlSi10Mg powder so that the two powders were evenly arranged, promoting full reaction of the powder during laser deposition and uniform distribution of the microstructure.

[0021] The shielding of Ti6Al4V powder in the present invention can effectively improve the laser absorption rate of AlSi10Mg powder.

[0022] In the present invention, Ti 5Si 3 The reinforcement phase is synthesized by laser in-situ reaction, which solves the problems of poor interface bonding between the added reinforcement phase and the matrix, interface debonding caused by poor wettability, and easy cracking between interfaces.

[0023] The volume ratio of Ti6Al4V powder to AlSi10Mg powder is controlled to be 5.5-6.5:4.5-3.5, preferably 6:4. 5 Si 3 The preferential formation of the phase and the formation of a network structure provide a prerequisite. Under high-power laser and low-speed scanning, it is conducive to the competition between the network and granular dispersion distribution of the enhanced phase in the Ti-Al intermetallic compound matrix. By optimizing the parameters, the particle dispersion enhancement and network enhancement have a synergistic effect, thereby significantly improving the friction and wear performance of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 SEM image of the composite material prepared in Example 1 magnified 2000 times; Figure 2 This is a SEM image of the composite material prepared in Example 1 magnified 10,000 times; Figure 3 is a SEM image of the composite material prepared in Comparative Example 1; Figure 4 is a SEM image of the composite material prepared in Comparative Example 2; Figure 5 This is a SEM image of the composite material prepared in Comparative Example 3 magnified 200 times; Figure 6 This is a SEM image of the composite material prepared in Comparative Example 3 magnified 2000 times.

[0025] from Figure 1 It can be seen that in the particle network composite reinforced titanium aluminum matrix composite prepared in the present invention, the white Ti 5 Si 3 The reinforcement phase is distributed in a network structure, and the other part is dispersed in the network structure in the form of particles, and no cracks are observed.

[0026] from Figure 2 It can be seen that the nanoscale white Ti 5 Si 3 The reinforcement phase is dispersed and evenly distributed.

[0027] from Figure 3 It can be seen that no obvious particle-network structure is formed in the material prepared under this condition.

[0028] from Figure 4It can be seen that the white Ti 5 Si 3 The reinforcement phase does not form a continuous network structure, and most of it is in the form of large-sized primary Ti 5 Si 3 The enhancement phase exists.

[0029] from Figure 5 It can be seen that there are large-sized cracks in the material prepared under this condition.

[0030] from Figure 6 It can be seen that the white Ti 5 Si 3 The reinforcement phase is distributed in a network pattern. DETAILED DESCRIPTION

[0031] In the embodiments and comparative examples of the present invention, the wear test method is to use a high-speed reciprocating friction and wear tester (HRS-2M) to perform a friction and wear test on the titanium-aluminum-based composite material coating at room temperature. The grinding ball used is a ZrO 2 All friction and wear tests at room temperature were conducted under a load of 40 N, a sliding speed of 100 mm / s, a sliding duration of 1800 s, and the relevant wear track length was set to 5 mm. The wear rate was calculated as ω = V loss / (L×F). Where V loss is the wear volume (mm 3 ), L is the sliding distance (m), and F is the loading load (N).

[0032] Example 1 A particle-net composite reinforced titanium-aluminum-based composite material and a preparation method thereof, comprising the following steps: Step 1: Use Ti6Al4V powder (particle size range is 53-105um) and AlSi10Mg powder (particle size range is 50-150um) which are fully mixed in a three-dimensional mixer according to a volume ratio of Ti6Al4V and AlSi10Mg powder of 6:4 as powder raw materials, place the mixed powder in a vacuum drying oven, and keep it warm at 60°C for 2h for use.

[0033] Step 2: After rinsing the titanium alloy substrate with clean water, place it in anhydrous ethanol for ultrasonic cleaning for 5 minutes and then dry it for use.

[0034] Step 3: Load the dried powder into the powder cylinder of the equipment, place the titanium alloy on the heating table, turn on the preheating function of the heating plate when the molding chamber is in an argon atmosphere with a low oxygen content (below 50ppm), preheat the substrate to the specified temperature, and use the laser deposition four-way coaxial powder feeding process. By adjusting the laser power and scanning speed, the mesh structure titanium aluminum-based composite material is deposited under the determined process parameters such as powder feeding speed and scanning spacing; when laser depositing the mesh structure titanium aluminum-based composite material, The laser power was set to 475W; The scanning speed was set to 420 mm / min; The substrate preheating temperature is 200°C.

[0035] Part of the Ti in the deposited titanium-aluminum matrix composite 5 Si 3 Phase is distributed in a network, and some granular Ti 5 Si 3 The phase is dispersed in the network structure, with a hardness of 760.2HV and a wear rate of 1.11×10 -4 mm 3 / Nm.

[0036] Example 2 The other conditions are the same as those in Example 1, except that: when laser depositing the titanium-aluminum-based composite material, The laser power is 350W; Scanning speed: 360 mm / min; No substrate preheat temperature.

[0037] Part of the Ti in the deposited titanium-aluminum matrix composite 5 Si 3 The phase is distributed in a network around the matrix, and some granular Ti 5 Si 3 The phase is dispersed in the network structure, with a hardness of 645.4HV and a wear rate of 1.32×10 -4 mm 3 / Nm.

[0038] Example 3 The other conditions are the same as those in Example 1, except that: when laser depositing the titanium-aluminum-based composite material, The laser power is 600W; Scanning speed 450mm / min; No substrate preheat temperature.

[0039] Part of the Ti in the deposited titanium-aluminum matrix composite 5 Si 3 The phase is distributed in a network around the matrix, and some granular Ti 5 Si3 The phase is dispersed in the network structure, with a hardness of 630.2HV and a wear rate of 1.30×10 -4 mm 3 / Nm.

[0040] Example 4 The other conditions are the same as those in Example 1, except that: when laser depositing the titanium-aluminum-based composite material, The laser power is 500W; Scanning speed 480 mm / min; The substrate preheating temperature is 300°C.

[0041] Part of the Ti in the deposited titanium-aluminum matrix composite 5 Si 3 The phase is distributed in a network around the matrix, and some granular Ti 5 Si 3 The phase is dispersed in the network structure, with a hardness of 740.7HV and a wear rate of 1.17×10 -4 mm 3 / Nm.

[0042] Comparative Example 1 The other conditions are the same as those in Example 1, except that: when laser depositing the titanium-aluminum-based composite material, The volume ratio of Ti6Al4V to AlSi10Mg powder is 7:3; The laser power is 600W; Scanning speed 420mm / min; No substrate preheat temperature.

[0043] Ti was not observed in the deposited titanium-aluminum matrix composites. 5 Si 3 The hardness of the reinforcement phase is 599.4HV and the wear rate is 1.54×10 -4 mm 3 / Nm.

[0044] Comparative Example 2 The other conditions are the same as those in Example 1, except that: when laser depositing the titanium-aluminum-based composite material, The volume ratio of Ti6Al4V and AlSi10Mg powders is 5:5; The laser power is 500W; Scanning speed 380mm / min; The substrate preheating temperature is 200°C.

[0045] The white Ti in the deposited titanium-aluminum matrix composite 5 Si 3Part of the reinforcement phase is distributed in a discontinuous network, and the other part is distributed in a large-sized primary Ti 5 Si 3 The reinforcement phase is dispersed, with a hardness of 463.8 HV and a wear rate of 3.72×10 -4 mm 3 / Nm.

[0046] Comparative Example 3 The other conditions are the same as those in Example 1, except that: when laser depositing the titanium-aluminum-based composite material, The laser power is 700W; Scanning speed 450mm / min; The substrate preheating temperature is 250°C.

[0047] In the deposited titanium-aluminum matrix composite material, part of Ti 5 Si 3 The phase is distributed in a network, but there are large-sized cracks. Its hardness is 516.9HV and its wear rate is 2.89×10 -4 mm 3 / Nm.

[0048] Comparative Example 4 The other conditions are the same as those in Example 1, except that: when laser depositing the titanium-aluminum-based composite material, Ti6Al4V is laser deposited on the surface of the titanium alloy as a comparative example; that is, AlSi10Mg powder is not introduced; The laser power is 500W; Scanning speed 380mm / min; The substrate preheating temperature is 200°C.

[0049] The hardness of the deposited Ti6Al4V coating is 371.6HV and the wear rate is 4.30×10 -4 mm 3 / Nm.

[0050] Comparative Example 5 The other conditions are the same as those in Example 1, except that: when laser depositing the titanium-aluminum-based composite material, The laser power was set to 300 W; The scanning speed was set to 420 mm / min; The substrate preheating temperature is 200°C.

[0051] In the deposited titanium-aluminum matrix composite material, part of Ti 5 Si 3 Phase is distributed in a network, and some granular Ti 5 Si 3The phase is dispersed in the network structure, but there are some microporous defects. Its hardness is 563.6HV and the wear rate is 2.33×10 -4 mm 3 / Nm.

[0052] Comparative Example 6 Other conditions are the same as those in Example 1, except that: Scanning speed 1200mm / min; The hardness of the deposited titanium-aluminum matrix composite coating is 320.7 HV and the wear rate is 5.13×10 -4 mm 3 / Nm. It can be seen from the embodiment and comparative example 6 that too fast scanning speed will quickly reduce the wear resistance of the product.

[0053] The above describes in detail the preferred implementation of this patent, but this patent is not limited to the above implementation. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of this patent.

Claims

1. A particle-net composite reinforced titanium-aluminum-based composite material, characterized in that: The particle-net composite reinforced titanium-aluminum-based composite material consists of a reinforcement phase and a matrix phase, wherein the reinforcement phase includes Ti5Si3 and the matrix phase includes a titanium-aluminum alloy. In the reinforcement phase, a portion of Ti5Si3 is distributed in a network structure and a portion is dispersed in a particle form.

2. The particle-net composite reinforced titanium-aluminum-based composite material according to claim 1, characterized in that: Granular dispersed nano Ti5Si3 particles.

3. The particle-net composite reinforced titanium-aluminum based composite material according to claim 1, characterized in that: The reinforcement phase is in-situ generated Ti5Si3; the matrix phase is Ti3Al phase.

4. The particle-net composite reinforced titanium-aluminum based composite material according to claim 1, characterized in that: In the reinforcement phase, a part of Ti5Si3 is distributed in a network structure, and a part of Ti5Si3 is dispersed in the network structure in a granular form.

5. A method for preparing a particle-net composite reinforced titanium-aluminum based composite material, characterized in that: The steps include: Step 1 Using Ti6Al4V powder and AlSi10Mg powder as raw materials, Ti6Al4V powder: AlSi10Mg powder = 5.5-6.5: 4.5-3.5 by volume ratio, prepare Ti6Al4V powder and AlSi10Mg powder, and then mix the prepared powders evenly to obtain standby powder; Step 2 The dry standby mixed powder was used as the processing object, and the particle-net composite reinforced titanium-aluminum matrix composite material was prepared by laser printing process. The laser printing was controlled as follows: The laser power is 350-610W; the laser scanning speed is 360-480mm / min.

6. The method for preparing a particle-net composite reinforced titanium-aluminum based composite material according to claim 5, characterized in that: The particle size range of Ti6Al4V powder is 53~105um, and the particle size range of AlSi10Mg powder is 50~150um.

7. The method for preparing a particle-net composite reinforced titanium-aluminum based composite material according to claim 6, characterized in that: The substrate heating temperature is room temperature-300°C.

8. The method for preparing a particle-net composite reinforced titanium-aluminum based composite material according to claim 7, characterized in that: During laser printing, the laser power is controlled to be 470-510W, the laser scanning speed is controlled to be 410-480mm / min, and the substrate heating temperature is controlled to be 190-300°C.

9. The method for preparing a particle-net composite reinforced titanium-aluminum based composite material according to claim 5, characterized in that: During laser printing, the laser power is controlled to be 475-500W, the laser scanning speed is 420-480mm / min, and the substrate heating temperature is 200-300°C.

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