Method for preparing high-performance laser additive titanium-based composite material based on B source selection

Abstract

The invention relates to a method for preparing a high-performance laser additive titanium-based composite material based on B source selection, which comprises the following steps of: preparing different B source composite powder, preparing a laser additive of different B source titanium-based composite materials, and performing room-temperature tensile test on the different B source titanium-based composite materials to obtain the strength and plasticity of the different B source titanium-based composite materials. And an optimal material is taken according to requirements. According to the method, the better source of the B element in the reinforcement phase is conveniently determined, the high-performance titanium-based composite material is preferably selected, the method is suitable for industrial application, and meanwhile, a reliable foundation is laid for popularization of a laser three-dimensional forming technology for preparing the high-performance titanium-based composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of metal matrix composites. Background Art

[0002] Titanium matrix composites combine the advantages of titanium alloy matrix and ceramic reinforcement phase, having high specific strength, specific stiffness, good high-temperature performance, corrosion resistance, etc., and have been widely used in aerospace and other fields. Among them, due to the fact that TiB whiskers have a density comparable to that of titanium, a similar coefficient of thermal expansion, high strength, high thermodynamic stability, and the interface between in-situ grown TiB whiskers and the titanium matrix is relatively clean, TiB whiskers have become a relatively common ceramic reinforcement phase in titanium matrix composites. The change in the in-situ reaction system, that is, different sources of B element, will cause changes in the size and morphology of in-situ generated TiB whiskers, thereby affecting the microstructure and mechanical properties of titanium matrix composites. Therefore, it is necessary to explore a suitable source of B element to achieve a proper match between the strength and toughness of titanium matrix composites.

[0003] The literature "Yi M, Zhang X, Liu G, et al. Comparative investigation on microstructures and mechanical properties of (TiB+TiC) / Ti-6Al-4V composites from Ti-B4C-C and Ti-TiB2-TiC systems[J]. Materials Characterization, 2018, 140: 281–289." discloses a method for preparing titanium matrix composites using the reactive hot pressing method with Ti6Al4V-B4C-C and Ti6Al4V-TiB2-TiC systems as raw materials, indicating that the size of TiB whiskers in the Ti6Al4V-TiB2-TiC system is larger than that of TiB whiskers in the Ti6Al4V-B4C-C system. However, the above method is more about the differences in externally added and in-situ generated TiC, and the properties of the composites have not been effectively improved.

[0004] The laser additive manufacturing method based on the principle of discrete + layer-by-layer stacking has a relatively fast cooling rate, which can make the size of the reinforcement phase finer and the distribution more uniform. And the high degree of freedom in forming also makes it have great application potential in the preparation of high-performance titanium matrix composites.

[0005] The invention patent with the publication number CN111151746A discloses a method for additive manufacturing of a titanium matrix composite material with a self - generated ultrafine network structure reinforcement. This method prepares titanium matrix composite powder with the reinforcement embedded in the matrix alloy powder through a crucible - free gas atomization method, realizing the nanosizing of the reinforcement size and obtaining an ultrafine network structure, which improves the strength of the titanium matrix composite material. However, this process is too complex and difficult to control, restricting the wide application of this method.

[0006] That is to say, when preparing the titanium matrix composite material in the above - mentioned published literature, the purpose of simplifying the process while improving the performance of the titanium matrix composite material has not been achieved. Summary of the Invention

[0007] The purpose of the present invention is to avoid the deficiencies of the prior art and provide a method for preparing a titanium matrix composite material with a simple process and significantly improving the performance of the titanium matrix composite material based on the selection of B source for preparing high - performance laser - additive titanium matrix composite materials.

[0008] To achieve the above - mentioned purpose, the technical solution adopted by the present invention is as follows: A method for preparing a high - performance laser - additive titanium matrix composite material based on the selection of B source, including the following steps: Step 1: Preparation of composite powders with different B sources: After mixing different titanium alloy powders with different ceramic reinforcement phase powders containing B element, ball - milling and powder mixing are carried out in sequence, and then drying is performed to obtain composite powders with different B sources; Among them, the mass ratio of the ceramic reinforcement phase powder to the mixed powder is 0.1wt% - 2.5wt%; Step 2: Preparation of titanium matrix composites with different B sources: The composite powders with different B sources are subjected to laser - additive printing with synchronous co - axial powder feeding at a laser power of 2000W - 3000W, a powder feeding speed of 4g / min - 15g / min, and a scanning speed of 240mm / min - 600mm / min, to obtain at least two titanium matrix composite specimens with different B - source formations and dimensions of (60 - 80)mm × (5 - 10)mm × (10 - 20)mm in the X, Y, and Z directions; Step 3: Perform a room - temperature tensile test on the titanium matrix composites with different B sources at a tensile cross - beam displacement rate of 1mm / min to obtain the strength and plasticity of the titanium matrix composites with different B sources, and select the optimal material according to requirements.

[0009] Furthermore, in Step 1, the ceramic reinforcement phase powder is at least two of boron carbide, titanium diboride, and titanium boride; the titanium alloy powder is Ti65 or Ti6242 titanium alloy powder; The ceramic reinforcing phase powder is irregularly shaped powder with a particle size of 0.05 μm to 4 μm, and the titanium alloy powder is spherical powder with a particle size of 53 μm to 150 μm.

[0010] Further, the ball milling and powder mixing in step one is carried out in a ball milling tank, and the grinding balls used in the ball milling and powder mixing are ZrO2 grinding balls or stainless steel balls; The ZrO2 grinding balls include ZrO2 grinding balls with diameters of 10 mm, 8 - 8.5 mm, and 5 mm in a mass ratio of 1:3:6, and the mass ratio of the ZrO2 grinding balls to the mass of the mixed powder is (2 - 7):1; The ball milling time during the ball milling and powder mixing is 0.5 h to 4 h, the ball milling speed is 150 rpm to 400 rpm, the ball milling direction is unidirectional rotation, the time for one unidirectional rotation is 60 min, after stopping for 5 min to 10 min, the next unidirectional rotation is carried out. After the powder mixing is completed, an 80 - 200 mesh sieve is used to separate the obtained composite powder and the grinding balls.

[0011] Further, the ceramic reinforcing phase powder is a mixed powder of at least two of boron carbide, titanium diboride, titanium boride and graphene; the titanium alloy powder is Ti65 or Ti6242 titanium alloy powder; The ceramic reinforcing phase powder is irregularly shaped powder with a particle size of 0.05 μm to 4 μm, and the titanium alloy powder is spherical powder with a particle size of 53 μm to 150 μm. The graphene is in the form of flakes, with a thickness of 1 nm to 3 nm and a sheet width > 50 μm.

[0012] Further, the ball milling and powder mixing in step one is carried out in a ball milling tank, and the grinding balls used in the ball milling and powder mixing are ZrO2 grinding balls or stainless steel balls; The ZrO2 grinding balls include ZrO2 grinding balls with diameters of 10 mm, 8 - 8.5 mm, and 5 mm in a mass ratio of 1:3:6, and the mass ratio of the ZrO2 grinding balls to the mass of the mixed powder is (2 - 7):1; During the ball milling and powder mixing, first the ceramic reinforcing phase powder and the titanium alloy powder are ball milled and mixed. The ball milling time is 0.5 h to 4 h, the ball milling speed is 150 rpm to 400 rpm, the ball milling direction is unidirectional rotation, the time for one unidirectional rotation is 60 min, after stopping for 5 min to 10 min, the next unidirectional rotation is carried out. After the powder mixing is completed, an 80 - 200 mesh sieve is used to separate the obtained composite powder and the grinding balls; Next, on a planetary ball mill, the composite powder of ceramic reinforcing phase powder and titanium alloy powder and graphene powder are ball-milled and mixed. The ball-milling time is 0.5 h to 4 h, the ball-milling speed is 150 rpm to 400 rpm, the ball-milling direction is unidirectional rotation, the time for one unidirectional rotation is 60 min, and after stopping for 5 min to 10 min, the next unidirectional rotation is carried out. After the powder mixing is completed, an 80-200 mesh sieve is used to separate the obtained composite powder from the grinding balls.

[0013] Further, before the above-mentioned ball-milling and powder mixing, the ball-milling tank is evacuated and filled with argon three times repeatedly to ensure that the ball-milling process is carried out in an inert gas atmosphere, effectively avoiding the introduction of oxygen elements.

[0014] Further, the drying process in step one is specifically as follows: The composite powder is evenly scattered on a tray and placed in a vacuum drying oven. The vacuum degree in the drying oven is maintained at ≥ -0.1 MPa, and it is dried for 2 h to 4 h under the condition of a drying temperature of 80 °C to 120 °C, avoiding excessive hydrogen and oxygen elements in the composite powder.

[0015] Further, the titanium matrix composites with different B sources in step two are formed by printing on a flat substrate. The surface of the substrate is turned smooth. Before use, the surface oil stain is first washed off with an organic solvent, and then it is repeatedly washed in an ultrasonic cleaner soaked with dishwashing liquid for 5 min to 20 min, then rinsed with clean water, and finally the surface of the substrate is wiped with anhydrous ethanol and dried with a hair dryer.

[0016] Further, the titanium matrix composites with different B sources in step two are formed by printing on a flat substrate. The printing is specifically as follows: The laser spot deposits a single track along the outermost circle of the specimen size, and then deposits single tracks in a cyclic and reciprocating manner along the X direction of the flat substrate. After one layer is completed, the laser scanning direction rotates 90°, deposits a single track along the outermost circle of the specimen size, and then deposits single tracks in a cyclic and reciprocating manner along the Y direction to form at least two titanium matrix composite specimens with different B sources formed; Or the laser spot deposits single tracks in a cyclic and reciprocating manner along the X direction to form at least two titanium matrix composite specimens with different B sources formed.

[0017] Further, the ceramic reinforcing phase powder is a mixed powder of titanium diboride or boron carbide and graphene; the titanium alloy powder is Ti65; The titanium diboride powder or boron carbide powder is an irregularly shaped powder with a particle size of 0.05 μm to 4 μm, and the titanium alloy powder is a spherical powder with a particle size of 53 μm to 150 μm; graphene is in the form of flakes with a thickness of 1 nm to 3 nm and a sheet width > 50 μm.

[0018] The beneficial effects of the present invention are as follows: By adjusting different sources of B element in the titanium matrix composite powder and adopting the laser additive manufacturing method, the preferred source of B element in the reinforcement phase is determined, high-performance titanium matrix composites are optimized, facilitating industrial application, and at the same time laying a reliable foundation for promoting the preparation of high-performance titanium matrix composites by laser solid forming technology. Brief Description of the Drawings

[0019] Figure 1 : Microstructure picture of Specific Example 5; Figure 2 : Dimensions of room temperature tensile specimen; Figure 3 : Microstructure picture of Specific Example 5. Specific Embodiments

[0020] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0021] To achieve the above object, the present invention provides the following specific embodiments: Example 1: A method for preparing high-performance laser additive titanium matrix composites based on B source selection, comprising the following steps: Step 1: Preparation of composite powders with different B sources: Mix different titanium alloy powders with different ceramic reinforcement phase powders containing B element, wherein the mass ratio of the ceramic reinforcement phase powder to the mixed powder is 0.1 wt% - 2.5 wt%; The ceramic reinforcement phase powder is at least two of boron carbide, titanium diboride, and titanium boride, and is irregularly shaped powder with a particle size of 0.05 μm - 4 μm; The titanium alloy powder is Ti65 or Ti6242 titanium alloy powder, and is spherical powder with a particle size of 53 μm - 150 μm; Step 2: Evacuate and fill the ball milling tank with argon three times repeatedly to ensure that the ball milling process is carried out in an inert gas atmosphere, effectively avoiding the introduction of oxygen element. Then, the mixed powder is ball milled and mixed in sequence to obtain composite powder; Among them, the ball milling and mixing is carried out in the ball milling tank, and the grinding balls used in the ball milling and mixing are ZrO2 grinding balls or stainless steel balls; The ZrO2 grinding balls include ZrO2 grinding balls with diameters of 10 mm, 8 - 8.5 mm, and 5 mm with a mass ratio of 1:3:6, and the mass ratio of the ZrO2 grinding balls to the mass of the mixed powder is (2 - 7):1; The ball milling time during ball milling and powder mixing is 0.5 h to 4 h, the ball milling speed is 150 rpm to 400 rpm, the ball milling direction is unidirectional rotation, the time for one unidirectional rotation is 60 min, and after stopping for 5 min to 10 min, the next unidirectional rotation is carried out. After the powder mixing is completed, an 80 - 200 mesh sieve is used to separate the obtained composite powder and grinding balls.

[0022] Step 3: Drying to obtain composite powders with different B sources; Among them, the ball - milled composite powder is evenly scattered on a tray and placed in a vacuum drying oven. The vacuum degree in the drying oven is maintained at ≥ - 0.1 MPa, and it is dried for 2 h to 4 h under the condition of a drying temperature of 80 °C to 120 °C, avoiding excessive hydrogen and oxygen elements in the composite powder.

[0023] Step 4: Preparation of titanium - based composites with different B sources: The titanium - based composites with different B sources are obtained by printing and forming on a flat substrate. The surface of the substrate is turned smooth. Before use, the surface oil stain is first washed off with an organic solvent, then it is repeatedly washed in an ultrasonic cleaner soaked with dishwashing liquid for 5 min to 20 min, then rinsed thoroughly with clean water, and finally wiped with anhydrous ethanol and dried with a hair dryer on the surface of the substrate.

[0024] The composite powders with different B sources are subjected to laser additive manufacturing with synchronous co - axial powder feeding at a laser power of 2000 W to 3000 W, a powder feeding speed of 4 g / min to 15 g / min, and a scanning speed of 240 mm / min to 600 mm / min. Specifically, the laser spot is deposited in a single pass along the outermost circle of the specimen size, and then single - pass deposition is carried out cyclically and reciprocally in the X - direction of the flat substrate. After one layer is completed, the laser scanning direction rotates 90°, and single - pass deposition is carried out along the outermost circle of the specimen size, and then single - pass deposition is carried out cyclically and reciprocally in the Y - direction to form at least two specimens of titanium - based composites with different B - source forming; At least two specimens of titanium - based composites with different B - source forming with dimensions of (60 - 80) mm × (5 - 10) mm × (10 - 20) mm in the X, Y, and Z directions are obtained; Step 5: Perform a room - temperature tensile test on the titanium - based composites with different B sources at a tensile cross - beam displacement rate of 1 mm / min to obtain the strength and plasticity of the titanium - based composites with different B sources, and select the optimal material according to requirements.

[0025] Example 2: The same as Example 1, except that in Step 1, the ceramic reinforcement phase powder is a mixed powder of at least two of boron carbide, titanium diboride, and titanium boride and graphene, and it is an irregular - shaped powder with a particle size of 0.05 μm to 4 μm; The titanium alloy powder is Ti65 or Ti6242 titanium alloy powder, and it is a spherical powder with a particle size of 53 μm to 150 μm; The graphene is in the form of flakes with a thickness of 1 nm to 3 nm and a sheet width > 50 μm.

[0026] In Step 2, the ball milling and powder mixing are carried out in a ball milling jar, and the grinding balls used in the ball milling and powder mixing are ZrO2 grinding balls or stainless steel balls; The ZrO2 grinding balls include ZrO2 grinding balls with diameters of 10 mm, 8 mm to 8.5 mm, and 5 mm in a mass ratio of 1:3:6, and the mass ratio of the ZrO2 grinding balls to the mass of the mixed powder is (2 to 7):1; When carrying out the ball milling and powder mixing, first, the ceramic reinforcing phase powder and the titanium alloy powder are ball milled and mixed. The ball milling time is 0.5 h to 4 h, the ball milling speed is 150 rpm to 400 rpm, the ball milling direction is unidirectional rotation, the time for one unidirectional rotation is 60 min, and after stopping for 5 min to 10 min, the next unidirectional rotation is carried out. After the powder mixing is completed, an 80 - 200 mesh sieve is used to separate the obtained composite powder and the grinding balls; Then, on a planetary ball mill, the composite powder of the ceramic reinforcing phase powder and the titanium alloy powder and the graphene powder are ball milled and mixed. The ball milling time is 0.5 h to 4 h, the ball milling speed is 150 rpm to 400 rpm, the ball milling direction is unidirectional rotation, the time for one unidirectional rotation is 60 min, and after stopping for 5 min to 10 min, the next unidirectional rotation is carried out. After the powder mixing is completed, an 80 - 200 mesh sieve is used to separate the obtained composite powder and the grinding balls.

[0027] In Step 4, the composite powders with different B sources are subjected to laser additive manufacturing with synchronous coaxial powder feeding at a laser power of 2000 W to 3000 W, a powder feeding speed of 4 g / min to 15 g / min, and a scanning speed of 240 mm / min to 600 mm / min. Specifically, the laser spot is cycled back and forth in the X - direction for single - pass deposition to form at least two titanium - based composite material specimens with different B - source formations.

[0028] At least two titanium - based composite material specimens with different B - source formations and having dimensions of (60 - 80)×(5 - 10)×(10 - 20) mm in the X, Y, and Z directions are obtained; Example 3: The same as Example 1, except that in Step 1, there are two kinds of mixed powders of titanium diboride and graphene, and boron carbide and graphene, and both the titanium diboride powder and the boron carbide powder are irregular - shaped powders with a particle size of 0.05 μm to 4 μm, the titanium alloy powder is Ti65, and the titanium alloy powder is spherical powder with a particle size of 53 μm to 150 μm; the graphene is in the form of flakes with a thickness of 1 nm to 3 nm and a sheet width > 50 μm.

[0029] That is, two titanium matrix composite specimens are finally obtained, and the optimal material is selected according to requirements.

[0030] To further illustrate the technical solutions and technical effects of the present invention, the following specific embodiments are provided: Specific Example 1: Step 1: (1) Take 1.02 g of boron carbide B4C powder and 148.98 g of Ti65 powder. Among them, B4C is an irregularly shaped powder with an average particle size of 50 nm, and the Ti65 alloy powder is spherical particles with an average particle size of 89 μm, forming a mixed powder of B4C ceramic reinforcing phase and Ti65 alloy; (2) Take 3 g of TiB2 powder and 147 g of Ti65 alloy powder. Among them, TiB2 is irregularly shaped with an average particle size of 4 μm, and the Ti65 powder is spherical particles with an average particle size of 89 μm, forming a mixed powder of TiB2 ceramic reinforcing phase and Ti65 alloy; Put the two kinds of mixed powders obtained in the above (1) and (2) into the ball milling tank respectively, and add ZrO2 grinding balls with masses of 60 g, 180 g, and 360 g and diameters of 10 mm, 8 mm, and 5 mm respectively; at the same time, evacuate and fill argon into the ball milling tank three times repeatedly to ensure that the ball milling process is carried out in an inert atmosphere, effectively avoiding the introduction of oxygen elements.

[0031] Finally, carry out ball milling and powder mixing on a planetary ball mill respectively. Set the ball milling time to 6 h, the ball milling speed to 300 rpm, the ball milling direction to one-way rotation, the time for one-way rotation to 60 min, stop for 5 min and then carry out the next one-way rotation. After the powder mixing is completed, use a sieve to separate the composite powder and the grinding balls, and obtain 0.68 wt%B4C / Ti65 composite powder and 2 wt%TiB2 / Ti65 composite powder respectively; (3) Take 0.32 g of B4C powder, 0.14 g of graphene powder, and 149.54 g of Ti65 alloy powder. Among them, B4C is an irregularly shaped powder with an average particle size of 50 nm, graphene is flaky with a thickness of 1 nm - 3 nm and a sheet width > 50 μm, and the Ti65 powder is spherical particles with an average particle size of 89 μm. First, mix the B4C powder and the Ti65 alloy to form a mixed powder of Ti65 alloy and B4C ceramic reinforcing phase; (4) Take 0.21 g of graphene powder, 0.78 g of TiB2 powder, and 149.01 g of Ti65 alloy powder. Among them, graphene is flaky with a thickness of 1 nm - 3 nm and a sheet width > 50 μm, TiB2 is irregularly shaped with an average particle size of 4 μm, and the Ti65 powder is spherical particles with an average particle size of 89 μm; first, mix the TiB2 powder and the Ti65 alloy to form a mixed powder of Ti65 alloy and TiB2 ceramic reinforcing phase; The two kinds of mixed powders obtained in the above (3) and (4) were respectively put into a ball milling tank, and ZrO2 grinding balls with masses of 60 g, 180 g, and 360 g and diameters of 10 mm, 8 mm, and 5 mm were respectively added; at the same time, the ball milling tank was evacuated and filled with argon three times repeatedly, ensuring that the ball milling process was carried out in an inert atmosphere and effectively avoiding the introduction of oxygen elements; Then, ball milling and powder mixing were respectively carried out on a planetary ball mill. The ball milling time was set to 6 h, the ball milling speed was 300 rpm, the ball milling direction was unidirectional rotation, the time for one unidirectional rotation was 60 min, and after stopping for 5 min, the next unidirectional rotation was carried out. After the powder mixing was completed, the composite powder and the grinding balls were separated using a sieve to obtain 0.21 wt%B4C / Ti65 composite powder and 0.52 wt%TiB2 / Ti65 composite powder respectively; Finally, graphene powder was respectively added to the obtained B4C / Ti65 composite powder and TiB2 / Ti65 composite powder, and ball milling and powder mixing were respectively carried out on a planetary ball mill. The ball milling time was set to 2 h, the ball milling speed was 250 rpm, the ball milling direction was unidirectional rotation, the time for one unidirectional rotation was 60 min, and after stopping for 5 min, the next unidirectional rotation was carried out. After the powder mixing was completed, the composite powder and the grinding balls were separated using a sieve to obtain graphene / B4C / Ti65 composite powder and graphene / TiB2 / Ti65 composite powder respectively; Step 2: The four kinds of composite powders obtained in the above (1), (2), (3), and (4) were evenly scattered on a tray and put into a vacuum drying oven. The vacuum degree in the drying oven was maintained at ≥ -0.1 MPa, the drying temperature was set to 120 °C, and the time was 2 h; Step 3: The four kinds of dried composite powders obtained were respectively poured into a powder feeder, a cleaned pure titanium substrate was installed, then the glove box was closed, argon was filled into the glove box for protection, and finally the position of the laser head was adjusted to make the coaxiality of the laser beam output consistent.

[0032] Step 4: The laser power was set to 3000 W, the powder feeding speed was 8 g / min, the scanning speed was 600 mm / min. The laser spot deposited a single pass along the outermost circle of the specimen size, and then deposited single passes in a cyclic reciprocating manner along the X direction. After one layer was completed, the laser scanning direction was rotated by 90°, and a single pass was deposited along the outermost circle of the specimen size, and then single passes were deposited in a cyclic reciprocating manner along the Y direction.

[0033] Finally, four formed material block specimens with dimensions of 65 (X direction) mm × 10 (Y direction) mm × 15 (Z direction) mm after laser additive manufacturing of the above four composite powders were obtained, and were respectively denoted as 0.68wt%B4C / Ti65 composite material specimen, 2wt%TiB2 / Ti65 composite material specimen, graphene / 0.21wt%B4C / Ti65 composite material specimen, and graphene / 0.52wt%TiB2 / Ti65 composite material specimen.

[0034] Step 5: Clean the four formed material block specimens respectively, and after drying, specifically: Gradually grind and polish the XOZ planes of the four composite material specimens successively with 180#, 400#, 800#, 1200#, 1500#, and 2000# SiC water sandpapers, deeply corrode half of the specimens with an etchant for 30 s, and finally clean the surface of the samples with absolute ethanol and dry them with a hair dryer for standby.

[0035] Step 6: Conduct microstructure observation and room temperature tensile test on the four cleaned and dried formed material block specimens, specifically: Use a Helios G3 UC focused ion / electron dual-beam electron microscope to observe the microstructures of the four obtained material specimens to obtain the particle and whisker bundle morphologies of the composite materials; And machine the room temperature tensile specimens of the specimens, and conduct room temperature tensile tests on an Instron3382 electronic universal testing machine to obtain the tensile strength and elongation after fracture of the composite materials.

[0036] Comprehensively evaluate the particle and whisker bundle morphologies, tensile strength, and elongation after fracture of each material, and select the optimal material according to requirements.

[0037] Specific Example 2: This example is the same as Specific Example 1, except that: When preparing the mixed powders in steps (1), (2), (3), and (4), the mixed powders were respectively ball-milled and mixed on a planetary ball mill. The ball-milling time was set to 3 h, the ball-milling speed was 300 rpm, the ball-milling direction was one-way rotation, the time for one-way rotation was 60 min, and after stopping for 5 min, the next one-way rotation was carried out. After the powder mixing was completed, the composite powder and grinding balls were separated using a sieve.

[0038] At the same time, in step 4, the laser power was set to 3000 W, the powder feeding speed was 5 g / min, and the scanning speed was 480 mm / min.

[0039] Specific Example 3: It is the same as Specific Example 1, except that: When preparing the mixed powders in steps (1), (2), (3) and (4), the mixed powders are respectively milled on a planetary ball mill. The ball milling time is set to 2 hours, the ball milling speed is set to 300 rpm, and the ball milling direction is unidirectional. The unidirectional rotation means rotating in the same direction for 60 minutes and stopping for 10 minutes.

[0040] When the composite powder and graphene powder are mixed in the preparation steps (3) and (4), the following steps are performed: The composite powder and graphene powder were ball-milled and mixed on a planetary ball mill. The ball milling time was set to 2 h, the ball milling speed was set to 250 rpm, and the ball milling direction was set to unidirectional rotation. Unidirectional rotation means rotating in the same direction for 60 min and stopping for 10 min.

[0041] At the same time, in step 4, the laser power is set to 2000 W, the powder feeding speed is 7 g / min, the scanning speed is 240 mm / min, the laser spot is cyclically reciprocated in a single-pass deposition along the X direction, and the size of the obtained molding material block sample is 65 (X direction) mm × 5 (Y direction) mm × 15 (Z direction) mm.

[0042] Specific example 4: The same as specific example 3, except that: When the composite powder and graphene powder are mixed in the preparation steps (3) and (4), the following steps are performed: Then, a sieve was used to separate the grinding balls from the mixed composite powder, and the composite powder and graphene powder were ball-milled and mixed on a planetary ball mill. The ball-milling time was set to 3 h and the ball-milling speed was set to 250 rpm.

[0043] Specific example 5: Figure 1 - Figure 2 As shown, Step 1: Put 1.02g of B4C powder, 148.98g of Ti65 powder and 600g of ZrO2 grinding balls into a ball mill, where B4C is irregular in shape with an average particle size of 50nm, Ti65 powder is spherical particles with an average particle size of 89μm, and the diameters of ZrO2 grinding balls are 10mm, 8mm, and 5mm, respectively, and the added masses are 60g, 180g, and 360g, respectively. The ball mill was repeatedly evacuated and filled with argon three times to ensure that the ball milling process was carried out in an inert atmosphere, effectively avoiding the introduction of oxygen elements.

[0044] The B4C and Ti65 mixed powders were milled on a planetary ball mill, and the milling time was set to 6 hours, the milling speed was set to 300 rpm, and the milling direction was set to unidirectional. After the mixing, the composite powder and the grinding balls were separated using a sieve to obtain a 0.68wt% B4C / Ti65 composite powder.

[0045] Scatter 0.68 wt%B4C / Ti65 composite powder evenly on the tray and place it in a vacuum drying oven. Keep the vacuum degree in the drying oven ≥ -0.1 MPa, set the drying temperature at 120 °C, and the time at 2 h.

[0046] Pour the dried 0.68 wt%B4C / Ti65 composite powder into the powder feeder, install a cleaned pure titanium substrate, then close the glove box, fill it with argon for protection, and finally adjust the position of the laser head to keep the coaxiality of the laser beam output consistent. Set the laser power at 3000 W, the powder feeding speed at 8 g / min, and the scanning speed at 600 mm / min. The laser spot deposits a single pass along the outermost circle of the specimen size, and then deposits single passes in a cyclic reciprocating manner along the X direction. After one layer is completed, the laser scanning direction rotates 90°, deposits a single pass along the outermost circle of the specimen size, and then deposits single passes in a cyclic reciprocating manner along the Y direction.

[0047] Obtain a 0.68 wt%B4C / Ti65 composite material specimen with a size of 65 (X direction) mm × 10 (Y direction) mm × 15 (Z direction) mm.

[0048] Step 2: Gradually grind and polish the XOZ plane of the 0.68 wt%B4C / Ti65 composite material specimen obtained in Step 1 with 180#, 400#, 800#, 1200#, 1500#, and 2000# SiC water sandpapers in sequence. Deeply corrode half of the specimen with the etchant for 30 s, and finally clean the surface of the sample with anhydrous ethanol and dry it with a hair dryer for standby.

[0049] Step 3: Observe the microstructure of the 0.68 wt%B4C / Ti65 composite material sample obtained in Step 2 using a Helios G3 UC focused ion / electron dual-beam electron microscope, as Figure 1 shown. It shows that a continuous network structure formed by TiB whiskers and TiC particles aggregates in the composite material, where TiB mostly appears in the shape of nano-scale whisker bundles.

[0050] Step 4: Machine a room-temperature tensile specimen from the 0.68 wt%B4C / Ti65 composite material obtained in Step 1, with the size as Figure 2 shown. Conduct a room-temperature tensile test on an Instron3382 electronic universal testing machine, with the displacement rate of the tensile crossbeam at 1 mm / min. The results show that the tensile strength of the 0.68 wt%B4C / Ti65 composite material is 930 MPa, and the elongation after fracture is 0.68%.

[0051] Step 5, put 3g TiB2 powder, 147g Ti65 powder and 600g ZrO2 grinding balls into a ball mill, wherein TiB2 is irregular in shape with an average particle size of 4μm, Ti65 powder is spherical particles with an average particle size of 89μm, and the diameters of ZrO2 grinding balls are 10mm, 8mm, and 5mm, respectively, and the added masses are 60g, 180g, and 360g, respectively. The ball mill was repeatedly evacuated and filled with argon three times to ensure that the ball milling process was carried out in an inert atmosphere, effectively avoiding the introduction of oxygen elements.

[0052] The TiB2 and Ti65 mixed powders were ball milled on a planetary ball mill. The ball milling time was set to 3 h, the ball milling speed was set to 300 rpm, and the ball milling direction was set to unidirectional rotation. After the powder mixing was completed, the composite powder and the grinding balls were separated using a sieve. A 2wt% TiB2 / Ti65 composite powder was obtained.

[0053] Evenly scatter 2wt% TiB2 / Ti65 composite powder on a tray and put it into a vacuum drying oven. Keep the vacuum degree in the drying oven ≥-0.1MPa, set the drying temperature to 120℃, and the drying time to 2h.

[0054] Pour the dried 2wt% TiB2 / Ti65 composite powder into the powder feeder, install the cleaned pure titanium substrate, then close the glove box, fill the glove box with argon gas for protection, and finally adjust the position of the laser head to keep the coaxiality of the laser head consistent. Set the laser power to 3000W, the powder feeding speed to 5g / min, and the scanning speed to 480mm / min. The laser spot deposits a single track along the outermost circle of the sample size, and then reciprocates in the X direction. After one layer is completed, the laser scanning direction rotates 90°, deposits a single track along the outermost circle of the sample size, and then reciprocates in the Y direction.

[0055] A molded 2wt%TiB2 / Ti65 composite material sample with a size of 65 (X direction) mm×10 (Y direction) mm×15 (Z direction) mm was obtained.

[0056] Step 6: The XOZ surface of the 2wt% TiB2 / Ti65 composite material sample obtained in step 5 is ground and polished step by step using 180#, 400#, 800#, 1200#, 1500#, and 2000# SiC water sandpaper in sequence. Half of the sample is deep-etched for 30 seconds using an etchant. Finally, the sample surface is cleaned with anhydrous ethanol and blown dry with a hair dryer for later use.

[0057] Step 7: Use Helios G3 UC focused ion / electron dual beam electron microscope to observe the microstructure of the 2wt% TiB2 / Ti65 composite material sample obtained in step 6. Figure 3As shown, it shows that a quasi - continuous network structure formed by the aggregation of TiB whiskers is formed in the composite material, where TiB mostly exists as whiskers in the micron scale.

[0058] Step 8: Process the 2wt%TiB2 / Ti65 composite material obtained in Step 1 into room - temperature tensile specimens. The dimensions are as Figure 3 shown. Conduct a room - temperature tensile test on an Instron 3382 electronic universal testing machine. The displacement rate of the tensile crossbeam is 1 mm / min. The results show that the tensile strength of the 2wt%TiB2 / Ti65 composite material is 1244 MPa, and the elongation after fracture is 2.85%.

[0059] Step 9: Take 0.32 g of B4C powder, 0.14 g of graphene powder, 149.54 g of Ti65 powder and 600 g of ZrO2 grinding balls and put them into a ball - milling tank. Among them, B4C is in an irregular shape with an average particle size of 50 nm, graphene is in a flaky shape with a thickness of 1 nm - 3 nm and a sheet width > 50 μm, Ti65 powder is in a spherical shape with an average particle size of 89 μm, and the diameters of the ZrO2 grinding balls are 10 mm, 8 mm, and 5 mm respectively, and the added masses are 60 g, 180 g, and 360 g respectively. The ball - milling tank is evacuated and filled with argon three times repeatedly to ensure that the ball - milling process is carried out in an inert atmosphere, effectively avoiding the introduction of oxygen elements.

[0060] First, ball - mill and mix the B4C / Ti65 composite powder on a planetary ball - mill. Set the ball - milling time to 2 h, the ball - milling speed to 300 rpm, and the ball - milling direction to one - way rotation. The so - called one - way rotation means rotating in the same direction for 60 min and stopping for 10 min.

[0061] Then use a sieve to separate the grinding balls from the mixed composite powder. Ball - mill and mix the composite powder and graphene powder on a planetary ball - mill. Set the ball - milling time to 2 h, the ball - milling speed to 250 rpm, and the ball - milling direction to one - way rotation. After the mixing of powders is completed, use a sieve to separate the composite powder and the grinding balls. Thus, the graphene / 0.21wt%B4C / Ti65 composite powder is obtained.

[0062] Evenly scatter the composite powder on a tray and put it into a vacuum drying oven. Keep the vacuum degree in the drying oven ≥ - 0.1 MPa, set the drying temperature to 120 °C, and the time to 2 h. Pour the dried composite powder into a powder feeder, install a cleaned pure titanium substrate, then close the glove box, fill the glove box with argon for protection, and finally adjust the position of the laser head to keep the coaxiality of the laser output consistent. Set the laser power to 2000 W, the powder feeding speed to 7 g / min, and the scanning speed to 240 mm / min. The laser spot deposits in a single - pass cycle along the X - direction. A formed graphene / 0.21wt%B4C / Ti65 composite material sample with dimensions of 65 (X direction) mm × 5 (Y direction) mm × 15 (Z direction) mm is obtained.

[0063] Step 10: The XOZ plane of the graphene / 0.21wt%B4C / Ti65 composite material sample obtained in Step 9 is successively polished with 180#, 400#, 800#, 1200#, 1500#, and 2000# SiC water sandpapers and polished. Half of the sample is deeply etched with an etchant for 30 s, and finally, the surface of the sample is cleaned with absolute ethanol and dried with a hair dryer for standby.

[0064] Step 11: A room-temperature tensile sample is machined from the graphene / 0.21wt%B4C / Ti65 composite material sample obtained in Step 10, and the dimensions are as Figure 2 shown. A room-temperature tensile test is carried out on an Instron 3382 electronic universal testing machine, and the displacement rate of the tensile crossbeam is 1 mm / min. The results show that the tensile strength of the composite material is 1206 MPa, and the elongation after fracture is 2.9%.

[0065] Step 12: Take 0.21 g of graphene powder, 0.78 g of TiB2 powder, 149.01 g of Ti65 powder, and 600 g of ZrO2 grinding balls and put them into a ball milling tank. The graphene is in flake shape, with a thickness of 1 nm - 3 nm and a sheet width > 50 μm. The TiB2 is in irregular shape, with an average particle size of 4 μm. The Ti65 powder is in spherical particles, with an average particle size of 89 μm. The diameters of the ZrO2 grinding balls are 10 mm, 8 mm, and 5 mm, and the added masses are 60 g, 180 g, and 360 g respectively. The ball milling tank is evacuated and filled with argon three times repeatedly to ensure that the ball milling process is carried out in an inert atmosphere, effectively avoiding the introduction of oxygen elements.

[0066] First, the TiB2 / Ti65 composite powder is ball milled and mixed on a planetary ball mill. The set ball milling time is 2 h, the ball milling speed is 300 rpm, and the ball milling direction is one-way rotation. The one-way rotation means rotating in the same direction for 60 min and stopping for 10 min. Then, the grinding balls are separated from the mixed composite powder using a sieve. The composite powder and graphene powder are ball milled and mixed on a planetary ball mill. The set ball milling time is 3 h, the ball milling speed is 250 rpm, and the ball milling direction is one-way rotation. After the powder mixing is completed, the composite powder and grinding balls are separated using a sieve. Thus, the graphene / 0.52wt%TiB2 / Ti65 composite powder is obtained.

[0067] The graphene / 0.52wt%TiB2 / Ti65 composite is evenly scattered on a tray and placed in a vacuum drying oven. The vacuum degree in the drying oven is maintained ≥ -0.1 MPa, the drying temperature is set at 120 °C, and the time is 2 h.

[0068] Pour the dried graphene / 0.52wt%TiB2 / Ti65 composite into the powder feeder, install the cleaned pure titanium substrate, then seal the glove box, fill argon gas into the glove box for protection, and finally adjust the position of the laser head to keep the coaxiality of the laser beam output consistent. Set the laser power to 2000W, the powder feeding speed to 7g / min, and the scanning speed to 240mm / min. The laser spot deposits in a single pass in a cyclic reciprocating manner along the X direction; Obtain a formed graphene / 0.52wt%TiB2 / Ti65 composite material sample with dimensions of 65 (X direction) mm × 5 (Y direction) mm × 15 (Z direction) mm.

[0069] Step 13: Gradually grind and polish the XOZ plane of the graphene / 0.52wt%TiB2 / Ti65 composite material sample obtained in Step 12 with 180#, 400#, 800#, 1200#, 1500#, and 2000# SiC water sandpapers in sequence. Deeply corrode half of the sample with the etchant for 30s, and finally clean the surface of the sample with anhydrous ethanol and dry it with a hair dryer for standby.

[0070] Step 14: Machine a room temperature tensile specimen from the graphene / 0.52wt%TiB2 / Ti65 composite material sample obtained in Step 13, with dimensions as Figure 3 shown. Conduct a room temperature tensile test on an Instron3382 electronic universal testing machine, with the displacement rate of the tensile crossbeam being 1mm / min. The results show that the tensile strength of the composite material is 1174MPa, and the elongation after fracture is 1.92%.

[0071] The volume fraction and proportion of the reinforcing phase in Steps 9 - 11 and Steps 12 - 14 are the same. The above results indicate that the titanium matrix composite material with B4C as the source of B element has a better strength - plasticity matching than the titanium matrix composite material added with TiB2.

[0072] The above are only the preferred specific examples of the present invention, and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing high-performance laser-added titanium-based composite materials based on B source selection, characterized in that: The following steps are involved: Step 1: Preparation of composite powders with different B sources: After mixing different titanium alloy powders with different ceramic reinforcement phase powders containing B element, the powders are ball milled and dried in sequence to obtain composite powders with different B sources; The mass ratio of the ceramic reinforcement phase powder to the mixed powder is 0.1-2.5wt%; Step 2: Preparation of titanium-based composite materials with different B sources: Composite powders of different B sources are subjected to laser additive printing with a laser power of 2000W to 3000W, a powder feeding speed of 4g / min to 15g / min, a scanning speed of 240mm / min to 600mm / min, and synchronous coaxial powder feeding to obtain at least two titanium-based composite material samples formed by different B sources with dimensions of (60 to 80) mm×(5 to 10) mm×(10 to 20) mm in the X, Y, and Z directions; Step 3: Conduct room temperature tensile tests on titanium-based composite materials with different B sources at a tensile beam displacement rate of 1 mm / min to obtain the strength and plasticity of titanium-based composite materials with different B sources, and select the optimal material according to demand.

2. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to claim 1, characterized in that: The ceramic reinforcement phase powder in step 1 is at least two of boron carbide, titanium diboride and titanium boride; the titanium alloy powder is Ti65 or Ti6242 titanium alloy powder; The ceramic reinforcement phase powder is an irregularly shaped powder with a particle size of 0.05 μm to 4 μm, and the titanium alloy powder is a spherical powder with a particle size of 53 μm to 150 μm.

3. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to claim 2, characterized in that: The ball milling powder mixing described in step 1 is carried out in a ball mill, and the grinding balls used in the ball milling powder mixing are ZrO2 grinding balls or stainless steel balls; The ZrO2 grinding balls include ZrO2 grinding balls with diameters of 10 mm, 8 mm to 8.5 mm, and 5 mm, respectively, in a mass ratio of 1:3:6, and the mass ratio of the ZrO2 grinding balls to the mass ratio of the mixed powder is (2 to 7):1; The ball milling time for the powder mixing is 0.5h to 4h, the ball milling speed is 150rpm to 400rpm, the ball milling direction is unidirectional rotation, the time of one unidirectional rotation is 60min, and the next unidirectional rotation is performed after stopping for 5min to 10min. After the powder mixing is completed, the obtained composite powder and the grinding ball are separated using an 80-200 mesh screen.

4. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to claim 1, characterized in that: The ceramic reinforcement phase powder is a mixed powder of at least two of boron carbide, titanium diboride, and titanium boride and graphene; the titanium alloy powder is Ti65 or Ti6242 titanium alloy powder; The ceramic reinforcement phase powder is an irregularly shaped powder with a particle size of 0.05 μm to 4 μm, and the titanium alloy powder is a spherical powder with a particle size of 53 μm to 150 μm. The graphene is in the form of a thin sheet with a thickness of 1 nm to 3 nm and a sheet width of more than 50 μm.

5. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to claim 4, characterized in that: The ball milling powder mixing described in step 1 is carried out in a ball mill, and the grinding balls used in the ball milling powder mixing are ZrO2 grinding balls or stainless steel balls; The ZrO2 grinding balls include ZrO2 grinding balls with diameters of 10 mm, 8 mm to 8.5 mm, and 5 mm, respectively, in a mass ratio of 1:3:6, and the mass ratio of the ZrO2 grinding balls to the mass ratio of the mixed powder is (2 to 7):1; When the powder is mixed by ball milling, the ceramic reinforcement phase powder and the titanium alloy powder are firstly mixed by ball milling, the ball milling time is 0.5h to 4h, the ball milling speed is 150rpm to 400rpm, the ball milling direction is unidirectional rotation, the time of one unidirectional rotation is 60min, and the next unidirectional rotation is performed after stopping for 5min to 10min. After the powder mixing is completed, the obtained composite powder and the grinding ball are separated using a 80-200 mesh screen; Next, on a planetary ball mill, the composite powder of the ceramic reinforcement phase powder and the titanium alloy powder and the graphene powder are ball-milled and mixed. The ball milling time is 0.5h to 4h, the ball milling speed is 150rpm to 400rpm, the ball milling direction is unidirectional rotation, and the time for one unidirectional rotation is 60min. After stopping for 5min to 10min, the next unidirectional rotation is performed. After the mixing is completed, the composite powder and the grinding balls are separated using an 80-200 mesh sieve.

6. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to claim 1, characterized in that: Before the ball milling and mixing, the ball mill was repeatedly evacuated and filled with argon three times to ensure that the ball milling process was carried out in an inert gas atmosphere, thereby effectively avoiding the introduction of oxygen.

7. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to claim 1, characterized in that: The drying process described in step 1 is specifically: The composite powder is evenly scattered on a tray and placed in a vacuum drying oven, the vacuum degree in the drying oven is maintained at ≥-0.1 MPa, and the powder is dried at a drying temperature of 80° C. to 120° C. for 2 h to 4 h, thereby avoiding excessive hydrogen and oxygen elements in the composite powder.

8. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to claim 1, characterized in that: The titanium-based composite materials with different B sources described in step 2 are printed on a flat substrate. The surface of the substrate is polished. Before use, the surface oil is first washed away with an organic solvent, and then repeatedly cleaned for 5 minutes to 20 minutes in an ultrasonic cleaner soaked with detergent, then rinsed with clean water, and finally wiped with anhydrous ethanol and the surface of the substrate was dried with a hair dryer.

9. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to claim 1, characterized in that: The titanium-based composite materials with different B sources described in step 2 are printed on a flat substrate, and the printing is specifically as follows: Depositing a single track of the laser spot along the outermost circle of the sample size, and then cyclically reciprocatingly depositing a single track along the X direction of the plane substrate, rotating the laser scanning direction by 90° after one layer is completed, depositing a single track along the outermost circle of the sample size, and then cyclically reciprocatingly depositing a single track along the Y direction to form at least two titanium-based composite material samples formed by different B sources; Or the laser spot is deposited in a single pass along the X direction in a cyclic reciprocating manner to form at least two titanium-based composite material samples formed by different B sources.

10. The method for preparing high-performance laser-added titanium-based composite materials based on B source selection according to any one of claims 1 to 9, The ceramic reinforcement phase powder is a mixed powder of titanium diboride or boron carbide and graphene; the titanium alloy powder is Ti65; The titanium diboride powder or boron carbide powder is an irregularly shaped powder with a particle size of 0.05 μm to 4 μm, and the titanium alloy powder is a spherical powder with a particle size of 53 to 150 μm; the graphene is in the form of flakes with a thickness of 1 to 3 nm and a flake width of >50 μm.

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