Titanium-based composite material and preparation method thereof

Abstract

The invention relates to the technical field of titanium-based composite materials, in particular to a titanium-based composite material and a preparation method thereof. The titanium-based composite material comprises, by mass, 0.5%-0.6% of C, 0.7%-0.8% of B4C, 0.02%-0.04% of H and the balance Ti-6Al-4V and inevitable impurity elements, and the content of the impurity elements is smaller than 0.01%. A base phase of the titanium-based composite material is an alpha-Ti phase and a beta-Ti phase, a TiB reinforcement phase and a TiC reinforcement phase are distributed on the base phase, the TiB reinforcement phase is in a rod shape, the size of the TiB reinforcement phase is 5-10 microns, the TiC reinforcement phase is in a block shape and an equiaxial shape, and the size of the TiC reinforcement phase is 5-10 microns. The titanium-based composite material disclosed by the invention has the advantages of uniform reinforcement phase distribution and good high-temperature deformability.

Description

Technical Field

[0001] The invention relates to the technical field of titanium-based composite materials, and in particular to a titanium-based composite material and a preparation method thereof. Background Art

[0002] Titanium alloy composites (TMCs), which have excellent properties such as high specific strength, specific stiffness, high temperature strength, corrosion resistance and low density, have been widely studied and applied worldwide in recent decades and have developed into an important type of material. Titanium-based composites have been widely used in military, aerospace and other industrial fields. However, due to the low plasticity and toughness of titanium alloy composites at room temperature and the small limit deformation, the forming processing of most titanium alloy composites must be carried out under hot conditions. However, the hot deformation conditions correspond to higher temperatures and flow stresses, lower strain rates, etc., which increases the difficulty of hot processing of materials; at the same time, the distribution of the reinforcing phase inside the matrix is ​​uneven, which is not conducive to the consistency of its organizational properties. Therefore, the application of titanium alloy composites is limited to a certain extent.

[0003] Therefore, obtaining a method to improve the uniformity of the internal reinforcement phase distribution and the high-temperature deformation capacity of titanium-based composites is of great significance to the microstructure uniformity and high-temperature deformation capacity of titanium-based composites. Summary of the invention

[0004] In order to solve the problem that the existing titanium-based composite material has poor high-temperature deformation ability, the present invention provides a titanium-based composite material and a preparation method thereof.

[0005] According to a first aspect of the present invention, the present invention provides a titanium-based composite material, comprising, by mass percentage:

[0006] C 0.5-0.6wt.%, B4C 0.7-0.8wt.% and H 0.02-0.04wt.%, the balance is Ti-6Al-4V and unavoidable impurity elements, the content of the impurity elements is less than 0.01%;

[0007] The base phase of the titanium-based composite material is an α-Ti phase and a β-Ti phase, and a TiB reinforcement phase and a TiC reinforcement phase are distributed in the base phase. The TiB reinforcement phase is in a rod shape, and the size of the TiB reinforcement phase is 5 to 10 μm. The TiC reinforcement phase is in a block shape and an equiaxed shape, and the size of the TiC reinforcement phase is 5 to 10 μm.

[0008] Preferably, the volume fraction ratio of the TiC reinforcement phase to the TiB reinforcement phase is 0.9-1.1:1, and the sum of the volume fractions of the TiC reinforcement phase and the TiB reinforcement phase is 5.6%-6.2%.

[0009] Preferably, the sum of the volume fractions of the TiC reinforcement phase and the TiB reinforcement phase is 6%.

[0010] Preferably, the mass ratio of the C to the B4C is 0.71-0.75:1.

[0011] Preferably, the purity of C is ≥99%, and the purity of B4C is ≥99%.

[0012] According to a second aspect of the present invention, the present invention provides a method for preparing a titanium-based composite material, comprising the following steps:

[0013] The raw materials containing Ti-6Al-4V alloy, C powder and B4C powder are first smelted to obtain a molten body in which C and B4C react with Ti-6Al-4V in situ to form a TiB reinforcement phase and a TiC reinforcement phase distributed in the titanium-based phase;

[0014] The smelted body is subjected to a second smelting in a mixed gas environment containing hydrogen and inert gas to obtain Ti-6Al-4V / (TiB+TiC)-H x Ingot casting, wherein x is the mass percentage of hydrogen content in the titanium-based composite material, and x is 0.02wt.% to 0.04wt.%.

[0015] Preferably, the volume fraction ratio of the hydrogen to the inert gas is 1:9.

[0016] Preferably, the first smelting comprises:

[0017] The first smelting environment is a vacuum of 6×10 -3 ~5.5×10 -3 MPa, the first smelting power is 150-160 kW, the first smelting current is 190-200 A, the first smelting time is 160-180 s, and the smelt is smelted alternately on the front and back sides for 4-5 times.

[0018] Preferably, the second smelting comprises:

[0019] The second melting environment is vacuum degree ≤5×10 -3 Pa, the pressure of the mixed gas is 6×10 -3 ~5.5×10 -3 MPa, the second smelting power is 100-120 kW, the second smelting current is 295-300 A, the second smelting time is 330-360 s, and the ingot is smelted alternately on the front and back sides for 3-4 times.

[0020] Preferably, when the first smelting and the second smelting are completed, the smelted body and the ingot are air-cooled to room temperature and then taken out.

[0021] In order to solve the problem of poor high temperature deformation ability of existing titanium-based composite materials, the present invention has the following advantages:

[0022] 1. The present invention improves the shortcomings of uneven composition and poor high-temperature deformation ability of titanium-based composite materials through vacuum induction melting and vacuum arc melting combined with plasma hydrogenation treatment. The reinforcement phase distribution in the internal structure of the prepared titanium-based composite matrix is ​​relatively uniform, and the high-temperature compressive strength can be reduced by 51MPa, thereby improving the high-temperature plastic deformation ability of the titanium-based composite material and achieving the improvement of the hot processing performance of the titanium-based composite material. Therefore, through a more sufficient in-situ autogenous reaction inside the composite material, the microstructure shows that the reinforcement phase distribution is relatively uniform, and most of the reinforcement phases are distributed in a blocky and nearly equiaxed shape, so that the thermal deformation ability of the titanium-based composite material is enhanced, and at the same time, it has high strength, high toughness, and is easy to produce.

[0023] 2. The raw materials of the present invention are widely available, low in price, simple in process and short in cycle, which is conducive to improving the high temperature deformation ability of titanium-based composite materials on a large scale. Therefore, the method for preparing titanium-based composite materials by the present invention has broad application prospects.

[0024] 3. The hydrogen in the titanium-based composite material of the present invention can act as a temporary alloying element, thereby improving the hot working properties of the titanium alloy composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The XRD pattern of the titanium-based composite material of Comparative Example 1 is shown;

[0026] Figure 2 shows the XRD pattern of the titanium-based composite material of Example 1;

[0027] Figure 3 The SEM image of the titanium-based composite material of Comparative Example 1 is shown;

[0028] Figure 4 shows a SEM image of the titanium-based composite material of Example 1;

[0029] Figure 5 A comparison diagram of the rheological stress of Example 1 and Comparative Example 1 is shown. DETAILED DESCRIPTION

[0030] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, rather than implying any limitation on the scope of the present disclosure.

[0031] As used herein, the term "including" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified.

[0032] According to the first aspect of the present invention, this embodiment discloses a titanium-based composite material, such as Figure 1 As shown, according to the mass percentage, it includes:

[0033] C 0.5-0.6wt.%, B4C 0.7-0.8wt.% and H 0.02-0.04wt.%, the balance is Ti-6Al-4V and unavoidable impurity elements, the content of the impurity elements is less than 0.01%;

[0034] The base phase of the titanium-based composite material is an α-Ti phase and a β-Ti phase, and a TiB reinforcement phase and a TiC reinforcement phase are distributed in the base phase. The TiB reinforcement phase is in a rod shape, and the size of the TiB reinforcement phase is 5 to 10 μm. The TiC reinforcement phase is in a block shape and an equiaxed shape, and the size of the TiC reinforcement phase is 5 to 10 μm.

[0035] In this embodiment, Ti-6Al-4V (TC4) titanium alloy is used as the matrix material, and C powders of different compositions and B4C powders are used as reinforcing phase raw materials. The raw materials are easy to obtain and inexpensive, which can greatly reduce production costs.

[0036] Preferably, the content of H is 0.028-0.039 wt.%, the content of C is 0.51-0.54 wt.%, and the content of B is 0.72-0.75 wt.%.

[0037] More preferably, the H content is 0.034-0.036 wt.%.

[0038] Preferably, when the strain rate is 0.1 to 0.5, the compressive strength of the titanium-based composite material is 192 to 242 MPa.

[0039] Preferably, the volume fraction ratio of the TiC reinforcement phase to the TiB reinforcement phase is 0.9-1.1:1, and the sum of the volume fractions of the TiC reinforcement phase and the TiB reinforcement phase is 5.6%-6.2%.

[0040] Preferably, the volume fraction ratio of the TiC reinforcement phase to the TiB reinforcement phase is 0.99-1.01:1.

[0041] Preferably, the sum of the volume fractions of the TiC reinforcement phase and the TiB reinforcement phase is 6%.

[0042] Preferably, the mass ratio of the C to the B4C is 0.71-0.75:1.

[0043] Preferably, the purity of C is ≥99%, and the purity of B4C is ≥99%.

[0044] According to the first aspect of the present invention, this embodiment discloses a method for preparing a titanium-based composite material, comprising the following steps:

[0045] The raw materials containing Ti-6Al-4V alloy, C powder and B4C powder are first smelted to obtain a molten body in which C and B4C react with Ti-6Al-4V in situ to form a TiB reinforcement phase and a TiC reinforcement phase distributed in the titanium-based phase;

[0046] The smelted body is subjected to a second smelting in a mixed gas environment containing hydrogen and inert gas to obtain Ti-6Al-4V / (TiB+TiC)-H x Ingot casting, wherein x is the mass percentage of hydrogen content in the titanium-based composite material, and x is 0.02wt.% to 0.04wt.%.

[0047] In this embodiment, the composite melting method (vacuum induction melting method and vacuum arc melting method) combined with plasma hydrogenation treatment improves the shortcomings of uneven composition and poor high-temperature deformation ability of the titanium-based composite material, and the reinforcement phase distribution in the internal structure of the prepared titanium-based composite material matrix is ​​relatively uniform, which improves the high-temperature plastic deformation ability of the titanium-based composite material and achieves the improvement of the hot processing performance of the titanium-based composite material. Therefore, through a more sufficient in-situ autogenous reaction inside the composite material, the microstructure is manifested as a relatively uniform distribution of the reinforcement phase, and most of the reinforcement phases are blocky and nearly equiaxed distribution, so that the thermal deformation ability of the titanium-based composite material is enhanced, and at the same time, it has high strength, high toughness, and is easy to produce.

[0048] Preferably, the volume fraction ratio of the hydrogen to the inert gas is 1:9.

[0049] In this embodiment, while ensuring the hydrogen content, the hydrogen environment is also ensured.

[0050] Preferably, the first smelting comprises:

[0051] The first smelting environment is a vacuum of 6×10 -3 ~5.5×10 -3MPa, the first smelting power is 150-160 kW, the first smelting current is 190-200 A, the first smelting time is 160-180 s, and the smelt is smelted alternately on the front and back sides for 4-5 times.

[0052] In this embodiment, multiple smelting processes are performed to improve the composition uniformity of the titanium-based composite material.

[0053] Preferably, the power and current in the smelting process before the front and back alternating smelting are less than the power and current in the front and back alternating smelting process. Since dust exists in the material when the reinforcing phase is introduced into the matrix during the first smelting, in order to make the dust raw material melt into the matrix better and achieve better in-situ autogenous reaction, the current and power of the initial smelting are selected to be lower, and after the in-situ reaction is completed, the current and power are increased during the next smelting to make the internal composition of the material more uniform.

[0054] Preferably, the second smelting comprises:

[0055] The second melting environment is vacuum degree ≤5×10 -3 Pa, the pressure of the mixed gas is 6×10 -3 ~5.5×10 -3 MPa, the second smelting power is 100-120 kW, the second smelting current is 295-300 A, the second smelting time is 330-360 s, and the ingot is smelted alternately on the front and back sides for 3-4 times.

[0056] In this embodiment, multiple smelting processes are performed to improve the composition uniformity of the titanium-based composite material.

[0057] Preferably, when the first smelting and the second smelting are completed, the smelted body and the ingot are air-cooled to room temperature and then taken out.

[0058] In this embodiment, after smelting, the material is cooled before being taken out to avoid oxidation of the material.

[0059] Preferably, the cooling time is 5-12 min, and the cooling rate is 150-200° C. / min.

[0060] Example 1

[0061] In-situ reaction smelting: C powder and B4C powder were wrapped with aluminum foil and then placed in a water-cooled copper crucible in a vacuum induction suspension furnace. The purity of C powder was ≥99%, and the purity of B4C powder was ≥99%. Ti-6Al-4V alloy was directly placed in the water-cooled copper crucible with C powder and B4C powder. Argon with a purity of more than 99% was filled into the vacuum induction suspension furnace. The vacuum degree in the vacuum induction suspension furnace was set to 6×10 -3MPa, with a power of 150 kW and a current of 190 A, the Ti-6Al-4V alloy, C powder and B4C powder were melted for 180 s, C and B4C reacted in situ with Ti-6Al-4V to form a molten body with TiB reinforcement phase and TiC reinforcement phase distribution on the titanium base phase, and the molten body was turned over by a robotic arm, and the front and back sides were alternately melted repeatedly for 4 times. Specifically, during the repeated melting process, the power was 160 kW, the current was 200 A, and the melting time for each time was 3 min. After the melting was completed, the molten body was formed and cooled by a composite cooling method of furnace cooling and air cooling. The cooling time in the furnace was 5 min, and the cooling rate was 150 ° C / min. Then the vacuum induction suspension furnace was opened and air cooled to room temperature.

[0062] Hydrogen smelting: The smelted body cooled to room temperature is placed in a water-cooled copper crucible in a vacuum arc furnace for smelting. The vacuum arc furnace is filled with hydrogen and argon with a purity of more than 99%. The volume fraction of hydrogen is 10%, the volume fraction of argon is 90%, and the pressure of the mixed gas formed by hydrogen and argon is 5.5×10 -3 MPa, and the vacuum degree in the vacuum induction suspension furnace was set to 5×10 -3 Pa, a power of 120 kW and a current of 300 A are used to melt the smelt for 330 s to form a button ingot, and the button ingot is turned over by a robotic arm, and the front and back sides are repeatedly melted alternately for 3 times. Specifically, during the repeated melting process, the power is 100 kW, the current is 295 A, and the melting time is 3 min each time. After the melting is completed, the button ingot is cooled by air cooling for 10 min, and then the vacuum arc furnace is opened to take out the button ingot to obtain the titanium-based composite material.

[0063] Finally, the actual hydrogen content in the titanium-based composite material was measured by a hydrogen-oxygen analyzer. The measurement range of hydrogen was 0.01-1000 ppm, and the hydrogen content in the titanium-based composite material was measured to be 0.036 wt.%.

[0064] The titanium-based composite material prepared in this embodiment comprises, by mass percentage, 0.55 wt.% C, 0.8 wt.% B4C and 0.036 wt.% H, and the remainder is Ti-6Al-4V and unavoidable impurity elements, and the content of the impurity elements is less than 0.01%.

[0065] The phase composition structure of button ingots was analyzed by X-ray diffraction. Figure 1 This is the XRD pattern of button ingot.

[0066] Example 2

[0067] In-situ reaction smelting: C powder and B4C powder were wrapped with aluminum foil and then placed in a water-cooled copper crucible in a vacuum induction suspension furnace. The purity of C powder was ≥99%, and the purity of B4C powder was ≥99%. Ti-6Al-4V alloy was directly placed in the water-cooled copper crucible with C powder and B4C powder. Argon with a purity of more than 99% was filled into the vacuum induction suspension furnace. The vacuum degree in the vacuum induction suspension furnace was set to 5×10 -3 MPa, with a power of 155 kW and a current of 195 A, the Ti-6Al-4V alloy, C powder and B4C powder were melted for 170 s, C and B4C reacted in situ with Ti-6Al-4V to form a molten body with TiB reinforcement phase and TiC reinforcement phase distribution on the titanium base phase, and the molten body was turned over by a robotic arm, and the front and back sides were alternately melted repeatedly for 5 times. Specifically, during the repeated melting process, the power was 160 kW, the current was 200 A, and the melting time for each time was 3 min. After the melting was completed, the molten body was formed and cooled by a composite cooling method of furnace cooling and air cooling. The cooling time in the furnace was 7 min, and the cooling rate was 150 ° C / min. Then the vacuum induction suspension furnace was opened and air cooled to room temperature.

[0068] Hydrogen smelting: The smelted body cooled to room temperature is placed in a water-cooled copper crucible in a vacuum arc furnace for smelting. The vacuum arc furnace is filled with hydrogen and argon with a purity of more than 99%. The volume fraction of hydrogen is 10%, the volume fraction of argon is 90%, and the pressure of the mixed gas formed by hydrogen and argon is 5.5×10 -3 MPa, and the vacuum degree in the vacuum induction suspension furnace was set to 5×10 -3 Pa, a power of 110 kW and a current of 300 A are used to melt the smelt for 350 s to form a button ingot, and the button ingot is turned over by a robotic arm, and the front and back sides are repeatedly melted alternately for 4 times. Specifically, during the repeated melting process, the power is 100 kW, the current is 295 A, and the melting time is 3 min each time. After the melting is completed, the button ingot is cooled by air cooling for 12 min, and then the vacuum arc furnace is opened to take out the button ingot to obtain the titanium-based composite material.

[0069] Example 3

[0070] In-situ reaction smelting: C powder and B4C powder were wrapped with aluminum foil and then placed in a water-cooled copper crucible in a vacuum induction suspension furnace. The purity of C powder was ≥99%, and the purity of B4C powder was ≥99%. Ti-6Al-4V alloy was directly placed in the water-cooled copper crucible with C powder and B4C powder. Argon with a purity of more than 99% was filled into the vacuum induction suspension furnace. The vacuum degree in the vacuum induction suspension furnace was set to 5.5×10 -3MPa, with a power of 160 kW and a current of 200 A, the Ti-6Al-4V alloy, C powder and B4C powder were melted for 160 s, and C and B4C reacted in situ with Ti-6Al-4V to form a molten body with TiB reinforcement phase and TiC reinforcement phase distribution on the titanium base phase. The molten body was turned over by a robotic arm, and the front and back sides were alternately melted repeatedly for 4 times. Specifically, during the repeated melting process, the power was 160 kW, the current was 200 A, and the melting time for each time was 3 min. After the melting was completed, the molten body was formed and cooled by a composite cooling method of furnace cooling and air cooling. The cooling time in the furnace was 7 min, and the cooling rate was 200 ° C / min. Then the vacuum induction suspension furnace was opened and air cooled to room temperature.

[0071] Hydrogen smelting: The smelted body cooled to room temperature is placed in a water-cooled copper crucible in a vacuum arc furnace for smelting. The vacuum arc furnace is filled with hydrogen and argon with a purity of more than 99%. The volume fraction of hydrogen is 10%, the volume fraction of argon is 90%, and the pressure of the mixed gas formed by hydrogen and argon is 5.5×10 -3 MPa, and the vacuum degree in the vacuum induction suspension furnace was set to 5×10 -3 Pa, a power of 100 kW and a current of 295 A are used to melt the smelt for 360 s to form a button ingot, and the button ingot is turned over by a robotic arm, and the front and back sides are repeatedly melted alternately for 4 times. Specifically, during the repeated melting process, the power is 100 kW, the current is 295 A, and the melting time is 3 min each time. After the melting is completed, the button ingot is cooled by air cooling for 12 min, and then the vacuum arc furnace is opened to take out the button ingot to obtain the titanium-based composite material.

[0072] Comparative Example 1

[0073] Comparative Example The hydrogen smelting method of Example 1 was used for smelting to obtain an in-situ autogenous reaction ingot, the difference being that only argon gas with a purity of more than 99% was filled into the vacuum arc furnace.

[0074] The phase composition structure of the ingot was analyzed by X-ray diffraction. Figure 2 XRD pattern of the ingot of Comparative Example 1.

[0075] The microstructure and high temperature compression properties of titanium-based composite materials before and after treatment by plasma hydrogenation combined with composite melting method are analyzed below.

[0076] (1) X-ray diffraction analysis

[0077] The titanium-based composite materials obtained in Example 1 and Comparative Example 1 were subjected to X-ray diffraction analysis. The XRD pattern of Example 1 is as follows: Figure 1 As shown, the XRD pattern of Comparative Example 2 is as follows Figure 2As shown. It can be seen that only four phases, namely, α phase, β phase, TiB and TiC, exist in the titanium-based composite materials corresponding to Example 1 and Comparative Example 1. The metal matrix phase is α-Ti and β-Ti, and the reinforcement phase is TiB and TiC. The XRD spectra of Example 1 and Comparative Example 1 show the same phase composition. The plasma hydrogenation combined with the composite smelting method in Example 1 does not change the phase composition in the composite material, and no hydride phase is generated in the diffraction spectrum results, which is due to the low hydrogen content.

[0078] (2) High temperature compression performance analysis

[0079] The high temperature compression performance of the titanium-based composite materials obtained in Example 1 and Comparative Example 1 was analyzed at a temperature of 850°C and a strain rate of 0.01s -1 When the strain is 0.1, 0.3, and 0.5, the results are as follows Figure 5 As shown. The peak stress of Example 1 after hydrogenation treatment is less than the peak stress of Comparative Example 1 which has not been hydrogenated. When the strain is 0.1, the peak value of the titanium-based composite material of Example 1 is 242MPa, and the peak value of the titanium-based composite material of Comparative Example 1 is 293MPa. The peak value of the titanium-based composite material of Example 1 is 51MPa lower than the peak value of the titanium-based composite material of Comparative Example 1. When the strain is 0.3, the peak value of the titanium-based composite material of Example 1 is 213MPa, and the peak value of the titanium-based composite material of Comparative Example 1 is 255MPa. The peak value of the titanium-based composite material of Example 1 is 42MPa lower than the peak value of the titanium-based composite material of Comparative Example 1. When the strain is 0.5, the peak stress of the titanium-based composite material prepared by plasma hydrogenation combined with composite smelting method in Example 1 is reduced from 231MPa to 192MPa compared with the peak value of the titanium-based composite material prepared by Comparative Example 2 which has not been subjected to plasma hydrogenation combined with composite smelting method. The peak value of the titanium-based composite material of Example 1 is reduced by 39MPa compared with the peak value of the titanium-based composite material of Comparative Example 1, that is, the peak stress is reduced by nearly 16.8%. Therefore, the high temperature flow stress of titanium-based composites can be reduced by plasma hydrogenation combined with composite melting.

[0080] In some embodiments, when the hydrogen content in the titanium-based composite material is 0.038 wt.%, the compressive strength of the composite alloy of Comparative Example 1 is reduced by 17.3%.

[0081] (3) Scanning electron microscopy analysis

[0082] The high temperature compression deformation structures of the titanium-based composite materials obtained in Example 1 and Comparative Example 1 were analyzed by scanning electron microscopy. Figure 3 As shown, the electron microscope image of Comparative Example 1 is as follows Figure 4 As shown. Comparative Example 1 The titanium-based composite material is not treated by plasma hydrogenation combined with composite melting method. Figure 4The deformation structure is coarse, the uniformity of the reinforcement phase distribution is poor, and there is a phenomenon of segregation. Part of the reinforcement phase is dendritic. Example 1 Titanium-based composite material is treated by plasma hydrogenation combined with composite smelting method. Figure 5 The reinforcement phase is more evenly distributed on the Ti-6Al-4V matrix, the microstructure is more uniform, the shape of the TiB reinforcement phase is rod-shaped, the size of the TiB reinforcement phase is 5-10μm, the shape of the TiC reinforcement phase is blocky and equiaxed, the size of the TiC reinforcement phase is 5-10μm, and the distribution characteristics of the dendritic reinforcement phase are weakened. The sum of the volume fractions of the TiC reinforcement phase and the TiB reinforcement phase in Example 1 is 6%, and the volume fractions of the TiC reinforcement phase and the TiB reinforcement phase in the titanium-based composite material are 3%. This shows that the titanium-based composite material of the present invention is obtained by plasma hydrogenation combined with composite smelting method, which can improve the microstructure of the titanium-based composite material, is beneficial to the thermal deformation process of the material, and then has a positive effect on the thermal processing performance of the material.

[0083] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in actual applications, various changes may be made thereto in form and detail without departing from the scope of the present disclosure.

Claims

1. A titanium-based composite material, characterized in that: In terms of mass percentage, it includes: C 0.5-0.6wt.%, B4C 0.7-0.8wt.% and H 0.02-0.04wt.%, the balance is Ti-6Al-4V and unavoidable impurity elements, the content of the impurity elements is less than 0.01%; The base phase of the titanium-based composite material is an α-Ti phase and a β-Ti phase, and a TiB reinforcement phase and a TiC reinforcement phase are distributed in the base phase. The TiB reinforcement phase is in a rod shape, and the size of the TiB reinforcement phase is 5 to 10 μm. The TiC reinforcement phase is in a block shape and an equiaxed shape, and the size of the TiC reinforcement phase is 5 to 10 μm.

2. A titanium-based composite material according to claim 1, characterized in that: The volume fraction ratio of the TiC reinforcement phase to the TiB reinforcement phase is 0.9-1.1:1, and the sum of the volume fractions of the TiC reinforcement phase and the TiB reinforcement phase is 5.6%-6.2%.

3. A titanium-based composite material according to claim 2, characterized in that: The total volume fraction of the TiC reinforcement phase and the TiB reinforcement phase is 6%.

4. The titanium-based composite material according to claim 1, characterized in that: The mass ratio of the C to the B4C is 0.71-0.75:

1.

5. The titanium-based composite material according to claim 1, characterized in that: The purity of C is ≥99%, and the purity of B4C is ≥99%.

6. A method for preparing a titanium-based composite material, characterized in that: The steps include: The raw materials containing Ti-6Al-4V alloy, C powder and B4C powder are first smelted to obtain a molten body in which C and B4C react with Ti-6Al-4V in situ to form a TiB reinforcement phase and a TiC reinforcement phase distributed in the titanium-based phase; The smelted body is subjected to a second smelting in a mixed gas environment containing hydrogen and inert gas to obtain Ti-6Al-4V / (TiB+TiC)-H x Ingot casting, wherein x is the mass percentage of hydrogen content in the titanium-based composite material, and x is 0.02wt.% to 0.04wt.%.

7. The method for preparing a titanium-based composite material according to claim 6, characterized in that: The volume fraction ratio of the hydrogen gas to the inert gas is 1:

9.

8. The method for preparing a titanium-based composite material according to claim 6, characterized in that: The first smelting comprises: The first smelting environment is a vacuum of 6×10 -3 ~5.5×10 -3 MPa, the first smelting power is 150-160 kW, the first smelting current is 190-200 A, the first smelting time is 160-180 s, and the smelt is smelted alternately on the front and back sides for 4-5 times.

9. The method for preparing a titanium-based composite material according to claim 6, characterized in that: The second smelting comprises: The second melting environment is vacuum degree ≤5×10 -3 Pa, the pressure of the mixed gas is 6×10 -3 ~5.5×10 -3 MPa, the second smelting power is 100-120 kW, the second smelting current is 295-300 A, the second smelting time is 330-360 s, and the ingot is smelted alternately on the front and back sides for 3-4 times.

10. The method for preparing a titanium-based composite material according to claim 6, characterized in that: When the first smelting and the second smelting are completed, the smelted body and the ingot are air-cooled to room temperature and then taken out.

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