Heat treatment solution coupled strengthening near-alpha titanium matrix composite and method of making

Abstract

The application discloses a kind of heat treatment solid solution coupling reinforced near α titanium matrix composite material and its preparation method, which comprises the following steps: one, near α titanium matrix powder is mixed with carbon black powder, TaC and NbC ceramic powder ball milling;Two, discharge plasma sintering;Three, high-temperature solid solution heat treatment and quenching;Four, aging heat treatment and cooling;Five, hot rolling.The application simultaneously uses α-Ti stabilizing element C and β-Ti stabilizing element Ta, Nb as additive element, cooperates to use high-temperature solid solution heat treatment and aging heat treatment process, realizes the coupling reinforcement between each part by adjusting the size morphology distribution of reinforcing phase and titanium alloy matrix, improves the strength of titanium alloy matrix, improves the physical incompatibility of titanium alloy matrix and ceramic phase, so as to improve the mechanical properties of near α titanium matrix composite material, higher than the mechanical properties of traditional titanium matrix composite material, suitable for aerospace field.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composites, specifically relating to a heat-treated solid solution coupled reinforced near-α titanium matrix composite and its preparation method. Background Technology

[0002] Titanium-based composites are a class of composite materials formed by adding reinforcing phases uniformly or non-uniformly into a titanium alloy matrix. These titanium-based composites exhibit high specific strength, good resistance to high-temperature softening, and corrosion resistance, and are widely used in the aerospace field. Therefore, further improving the performance of titanium-based composites to expand their application range and value is of great significance.

[0003] Various forms of carbon, boron, and silicon sources are often introduced into titanium-based composites to generate in-situ reinforcing phases such as TiC ceramic particles, TiB ceramic whiskers, and Ti5Si3 with the titanium matrix. Among these, the network structure formed by the TiC ceramic reinforcing phase, combined with the hierarchical structure of dispersed Ti5Si3 particles within the network, exhibits excellent comprehensive mechanical properties and has therefore attracted widespread research attention. Solution treatment and aging treatment are commonly used heat treatment methods for improving the matrix microstructure and corresponding mechanical properties of titanium alloys. However, rationally utilizing heat treatment methods in the preparation process of titanium-based composites to improve their mechanical properties is a complex and challenging task. In titanium-based composites, the ceramic reinforcing phase is usually minimally affected by heat treatment, and its size distribution is difficult to alter after in-situ formation. Furthermore, the titanium matrix is ​​a titanium alloy, which is extremely sensitive to changes in heat treatment process parameters. Therefore, rationally adjusting the matrix microstructure and properties using heat treatment processes to coordinate the vastly different physical properties of the ceramic reinforcing phase is extremely difficult.

[0004] Therefore, if suitable ceramic reinforcing phases and titanium alloy matrix reinforcing elements can be selected, and certain process methods and heat treatment methods are used to adjust the size and morphology distribution of the reinforcing phase and titanium alloy matrix, improve the strength of the titanium alloy matrix, and improve the physical compatibility between the titanium alloy matrix and the ceramic phase, it is expected to further improve the mechanical properties of titanium-based composite materials and greatly help improve the performance of practical applications. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a method for preparing near-α titanium-based composite materials with heat treatment and solid solution coupling reinforcement, addressing the shortcomings of the prior art. This method selects α-Ti stabilizing element C and β-Ti stabilizing elements Ta and Nb as additive elements, and employs high-temperature solid solution heat treatment and aging heat treatment processes. By adjusting the size and morphology distribution of the reinforcing phase and the titanium alloy matrix, the coupling reinforcement between the various parts is achieved, improving the strength of the titanium alloy matrix and mitigating the physical incompatibility between the titanium alloy matrix and the ceramic phase. This improves the mechanical properties of the near-α titanium-based composite material, solving the problem of improving the mechanical properties of titanium-based composite materials using heat treatment.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a heat-treated solid solution coupled reinforced near-α titanium-based composite material, characterized in that the method includes the following steps:

[0007] Step 1: The near-α titanium-based powder is ball-milled and mixed with carbon black powder, TaC and NbC ceramic powder to obtain a near-α titanium-based composite powder that is coated with carbon black and has TaC and NbC ceramic powder embedded on its surface.

[0008] Step 2: The near-α titanium-based composite powder obtained in Step 1, which is coated with carbon black and has TaC and NbC ceramic powder embedded on its surface, is subjected to discharge plasma sintering to obtain a sintered near-α titanium-based composite material.

[0009] Step 3: Place the sintered near-α titanium-based composite material obtained in Step 2 under vacuum or gas protection, and perform high-temperature solution heat treatment and quenching in a heat treatment furnace to obtain the solution-quenched near-α titanium-based composite material.

[0010] Step 4: Place the solution-quenched near-α titanium-based composite material obtained in Step 3 under vacuum or gas protection, perform aging heat treatment in a heat treatment furnace, and then cool to obtain the aging near-α titanium-based composite material.

[0011] Step 5: The aged near-α titanium-based composite material obtained in Step 4 is hot-rolled to obtain a plate of heat-treated solid solution coupled reinforced near-α titanium-based composite material.

[0012] This invention uses carbon black, TaC, and NbC refractory ceramic powders as raw material additives. The near-α titanium-based composite powder is mixed with the additives by mechanical ball milling, and then a sintered titanium-based composite material is prepared by plasma discharge sintering. After that, the microstructure of the reinforcing phase and the titanium alloy matrix is ​​adjusted by heat treatment processes including high-temperature solution heat treatment and aging heat treatment. Finally, the plate of heat-treated solution-coupled reinforced near-α titanium-based composite material is obtained by hot deformation rolling.

[0013] The additives of this invention select two types of elements. One type is α-Ti phase stabilizing element C, mainly derived from carbon black, with a small amount derived from TaC and NbC nano-ceramic powders. During plasma sintering, only a very small amount of C will diffuse into the titanium matrix through thermal diffusion, playing a certain role in solid solution strengthening. Most of the C mainly reacts with Ti in situ to form TiC ceramic particles and form a network reinforcing phase structure. However, due to C segregation, larger TiC ceramic particles are produced. The other type is β-Ti stabilizing elements Ta and Nb, derived from TaC and NbC nano-ceramic powders. During plasma sintering, Ta and Nb are completely dissolved into the titanium matrix. Due to the large difference in atomic size between the solid-solution elements Ta and Nb and the elements in the titanium matrix, they will play a certain degree of solid solution strengthening. However, because Ta and Nb are refractory elements with low thermal diffusion coefficients, the element distribution will show a certain gradient and non-uniformity during the short plasma sintering process.

[0014] To address this issue, this invention employs a high-temperature solution heat treatment followed by quenching of the sintered near-α titanium-based composite material, based on the Ti-C phase diagram. Through prolonged high-temperature solution treatment, TiC ceramic particles dissolve, while C re-dissolves into the titanium matrix, primarily into the primary α-Ti matrix. Simultaneously, Ta and Nb uniformly dissolve into the β-Ti matrix. After quenching, a heterogeneous matrix is ​​obtained, comprising a primary α-Ti structure strengthened by C supersaturated solution treatment and a quenched β-Ti structure uniformly strengthened by Ta and Nb solution treatment. Therefore, this invention, using a high-temperature solution heat treatment and quenching process, not only avoids the problems of coarse TiC ceramic particles formed in situ during sintering and uneven Ta and Nb solution treatment, but also significantly enhances the solution strengthening effect, greatly improving the strength of the titanium matrix.

[0015] However, solution-quenched microstructures can lead to brittle fracture in near-α titanium-based composites due to their coarse structure, excessive strength, and inconsistent deformation capacity. Therefore, this invention proposes an aging heat treatment process after solution quenching. By aging heat treating the solution-quenched near-α titanium-based composite, a certain amount of supersaturated C precipitates TiC along the defect sites of the titanium matrix and continues to grow along the original residual TiC sites, resulting in a finer, more dispersed, and uniformly distributed TiC ceramic reinforcing phase compared to the sintered state. Simultaneously, after solution aging heat treatment, it is easier to precipitate the Ti5Si3 second phase in Si-containing titanium matrices such as TA19, which is beneficial to improving the mechanical properties of near-α titanium-based composites. Finally, the quenched β-Ti microstructure decomposes into nano-sized secondary α-Ti+β-Ti aged microstructures during the aging process, and encapsulates the larger-sized C-supersaturated primary α-Ti microstructure, thereby obtaining an age-strengthened microstructure with multiple reinforcing phases and heterogeneous structures. Compared to the solution-quenched microstructure, the microstructure of near-α titanium-based composites is a coupling product of reinforcing phases of various sizes, which is more capable of pinning and storing dislocations, greatly improving the strength of near-α titanium-based composites. The nanoscale aged microstructure can better coordinate deformation, improve stress concentration and load transfer, and avoid premature brittle fracture of near-α titanium-based composites before yielding.

[0016] Finally, the present invention hot-rolls the aged near-α titanium-based composite material to achieve hot rolling strengthening, forming a plate of heat-treated solid solution coupled strengthening of the near-α titanium-based composite material. While controlling plasticity loss as much as possible, the strength of the near-α titanium-based composite material is greatly enhanced.

[0017] The preparation method of the above-mentioned heat treatment solid solution coupled reinforcement near-α titanium-based composite material is characterized in that the near-α titanium-based powder in step one is TA11, TA15 or TA19, and the near-α titanium-based powder is a spherical powder with a particle size of 15μm to 53μm.

[0018] The above-mentioned method for preparing heat-treated solid solution coupled reinforced near-α titanium-based composite material is characterized in that the TaC ceramic powder in step one is a particle with a particle size of 0.1 μm to 1 μm, and the NbC ceramic powder is a particle with a particle size of 0.1 μm to 1 μm.

[0019] The above-mentioned method for preparing heat-treated solid solution coupled reinforced near-α titanium-based composite material is characterized in that, in step one, the total mass percentage of the additives TaC and NbC ceramic powder and carbon black powder in the near-α titanium-based composite powder is 1% to 2%, wherein the mass percentage of carbon black powder is 0.1% to 0.8%, and the mass ratio of TaC to NbC ceramic powder is 1:9 to 9:1; the ball milling speed is 150 rpm to 250 rpm, the ball-to-material ratio is 3 to 6:1, and the ball milling time is 6 h to 10 h, and the ball milling includes two stages: in the first stage, 1 / 2 of the additives TaC and NbC ceramic powder and carbon black powder are added, and the ball milling time is 1 h to 3 h; in the second stage, the remaining 1 / 2 of the additives TaC and NbC ceramic powder and carbon black powder are added, and the ball milling time is 5 h to 7 h.

[0020] The above-mentioned method for preparing near-α titanium-based composite materials by heat treatment and solid solution coupling reinforcement is characterized in that the discharge plasma sintering process in step two is as follows: the near-α titanium-based composite powder coated with carbon black and embedded with TaC and NbC ceramic powders on the surface is placed in a graphite mold and kept at constant pressure and temperature for 5 min to 10 min under the conditions of sintering temperature of 900℃~1100℃ and sintering pressure of 40MPa~50MPa.

[0021] The above-mentioned method for preparing heat-treated solid solution coupled reinforced near-α titanium-based composite material is characterized in that the temperature of the high-temperature solid solution heat treatment in step three is 900℃~1100℃, and the holding time is 6h~12h; the quenching medium is water or oil.

[0022] The above-mentioned method for preparing heat-treated solid solution coupled reinforced near-α titanium-based composite materials is characterized in that the aging heat treatment temperature in step four is 400℃~600℃, and the holding time is 6h~12h; the cooling method is furnace cooling.

[0023] The above-mentioned method for preparing heat-treated solid solution coupled reinforced near-α titanium-based composite materials is characterized in that the hot rolling temperature in step five is 800℃~1000℃ and the holding time is 5min~10min.

[0024] Meanwhile, the present invention also discloses a heat-treated solid solution coupled reinforced near-α titanium-based composite material, characterized in that it is prepared by the above-described method.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. This invention uses α-Ti stabilizing element C and β-Ti stabilizing elements Ta and Nb as additive elements, and employs high-temperature solution heat treatment and quenching process to make each element dissolved in the titanium matrix, which improves the uneven distribution of refractory and difficult-to-diff elements, obtains a titanium matrix with supersaturated C solution, improves the solid solution strengthening effect, and enhances the strength of near-α titanium matrix composites.

[0027] 2. In this invention, after high-temperature solution heat treatment causes TiC to decompose and C to dissolve into the matrix, aging heat treatment is then used to cause TiC to precipitate along the defects and grow along the residual TiC sites. This improves the non-uniformity of TiC generated in sintered state, improves the size of excessively large TiC particles, enhances the dispersion distribution effect, and solves the problem of incoordination between ceramic phase and titanium alloy matrix deformation.

[0028] 3. This invention employs high-temperature solution heat treatment combined with aging heat treatment, which causes the precipitation of Ti5Si3 second phase in the Si-containing titanium matrix. This is beneficial to improving the mechanical properties of near-α titanium-based composite materials. Together with the generated TiC ceramic reinforcing phase, it forms an aging-strengthened microstructure with multiple reinforcing phases and heterogeneous structures, improving the dispersion strengthening effect, increasing the strength of near-α titanium-based composite materials, and mitigating the performance problems caused by the significant differences between the reinforcing phase and the titanium alloy matrix phase.

[0029] 4. This invention employs high-temperature solution heat treatment combined with aging heat treatment to strengthen the titanium matrix. After high-temperature solution heat treatment and quenching, a large primary α-Ti matrix phase and a quenched β-Ti matrix phase with strong brittleness are obtained. After aging, the quenched β-Ti matrix phase decomposes into nano-sized secondary α-Ti+β-Ti matrix phases, which encapsulate the high-strength primary α-Ti matrix phase to form a heterogeneous matrix structure. This effectively alleviates the uncoordinated deformation between matrix phases during deformation, retaining both high strength and a small amount of plasticity. Thus, in the subsequent hot rolling process, this structure can effectively utilize the strengthening mechanisms of hot rolling, such as dislocation storage and recrystallization, to obtain higher mechanical properties.

[0030] 5. The heat-treated solid solution coupled reinforced near-α titanium-based composite material prepared by this invention has extremely high strength and a small amount of plasticity. It exhibits a tensile strength of 1842 MPa and an elongation of 2.2% at room temperature, which are higher than the mechanical properties of traditional titanium-based composite materials.

[0031] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0032] Figure 1 This is a scan image of the solution-quenched near-α titanium-based composite material prepared in Example 1 of the present invention at a scale bar of 10 μm.

[0033] Figure 2This is a scan image of the aged near-α titanium-based composite material prepared in Example 1 of the present invention at a scale bar of 10 μm.

[0034] Figure 3 The images show the engineering stress-strain curves of the products prepared in Example 1 and Comparative Examples 1-4 of this invention at room temperature. Detailed Implementation

[0035] In Examples 1-3 and Comparative Examples 1-4 of this invention, the titanium-based powder used is spherical powder with a particle size of 15μm to 53μm, the TaC ceramic powder used is particle with a particle size of 0.1μm to 1μm, and the NbC ceramic powder is particle with a particle size of 0.1μm to 1μm.

[0036] Example 1

[0037] This embodiment includes the following steps:

[0038] Step 1: Weigh 98.5% of TA19 near-α titanium-based powder, 0.5% of carbon black powder, 0.5% of TaC ceramic powder, and 0.5% of NbC ceramic powder by weight percentage. Place all TA19 near-α titanium-based powder, 1 / 2 of the additives TaC and NbC ceramic powder, and carbon black powder in a stainless steel ball mill jar with a ball-to-powder ratio of 3:1. Use a planetary ball mill to ball-mill and mix at 200 rpm for 1 hour. Then add the remaining 1 / 2 of the additives TaC and NbC ceramic powder and carbon black powder, and ball-mill and mix at 200 rpm for 7 hours to obtain near-α titanium-based composite powder coated with carbon black and embedded with TaC and NbC ceramic powder on the surface.

[0039] Step 2: The near-α titanium-based composite powder obtained in Step 1, which is coated with carbon black and has TaC and NbC ceramic powder embedded on its surface, is placed into a graphite mold for discharge plasma sintering. The sintering temperature is 1000℃, the sintering pressure is 40MPa, and the constant pressure and temperature are maintained for 10min. After cooling in the furnace, the powder is demolded to obtain the sintered near-α titanium-based composite material.

[0040] Step 3: Place the sintered near-α titanium-based composite material obtained in Step 2 under vacuum protection and perform high-temperature solution heat treatment in a heat treatment furnace. The temperature of the high-temperature solution heat treatment is 1000℃ and the holding time is 8h. Then, use water as a medium for quenching to obtain the solution-quenched near-α titanium-based composite material.

[0041] Step 4: The solution-quenched near-α titanium-based composite material obtained in Step 3 is placed under vacuum protection and subjected to aging heat treatment in a heat treatment furnace at a temperature of 500℃ for 8 hours, and then cooled with the furnace to obtain the aging near-α titanium-based composite material.

[0042] Step 5: The aged near-α titanium-based composite material obtained in Step 4 is hot-rolled at a temperature of 900℃ and a holding time of 10 min to obtain a plate of heat-treated solid solution coupled reinforced near-α titanium-based composite material.

[0043] Figure 1 This is a scan image of the solution-quenched near-α titanium-based composite material prepared in this embodiment at a scale length of 10 μm. Figure 1 It can be seen that the near-α titanium matrix composite material in the solution-quenched state contains a small amount of undissolved TiC ceramic particles, grown primary α-Ti matrix phase, and quenched β-Ti matrix phase. At this time, the near-α titanium matrix composite material in the solution-quenched state has a coarse structure, the deformation between the phases is not coordinated, the material is brittle, and the strength cannot be expressed.

[0044] Figure 2 This is a scan image of the aged near-α titanium-based composite material prepared in this embodiment at a scale length of 10 μm. Figure 2 It can be seen that the near-α titanium-based composite material in this aged state contains a large number of residual undissolved and aged precipitated TiC ceramic particles, primary α-Ti matrix phase, and secondary α-Ti+β-Ti matrix phase formed by the decomposition of quenched β-Ti matrix phase. Dispersed precipitated Ti5Si3 phase is also observed. Each phase is indicated by the arrow. At this time, the near-α titanium-based composite material in this aged state has obtained a variety of microstructures and reinforcing phases with different sizes and morphologies. The components have a coordinated and coupled effect with each other, which is conducive to further improving the strength of the material.

[0045] Comparative Example 1

[0046] The difference between this comparative example and Example 1 is that only steps one and two were performed, and steps three to five were not performed. The product obtained was a sintered near-α titanium-based composite material.

[0047] Comparative Example 2

[0048] The difference between this comparative example and Example 1 is that only steps one to three were performed, and steps four to five were not performed. The product obtained was a near-α titanium-based composite material in a solution-quenched state.

[0049] Comparative Example 3

[0050] The difference between this comparative example and Example 1 is that only steps one to three and five are performed, while step four is not performed. The product obtained is a near-α titanium-based composite material plate rolled in a solution-quenched state.

[0051] Comparative Example 4

[0052] The difference between this comparative example and Example 1 is that only steps one to four were performed, and step five was not performed. The product obtained was an aged near-α titanium-based composite material.

[0053] Figure 3 The images show the engineering stress-strain curves at room temperature for the products prepared in Example 1 and Comparative Examples 1-4 of this invention. Figure 3 It can be seen that the room temperature tensile strength of the sintered near-α titanium-based composite material prepared in Comparative Example 1 via steps one to two is 1347 MPa, and the elongation after fracture is 3.5%. The room temperature tensile strength of the solution-quenched near-α titanium-based composite material prepared in Comparative Example 2 via steps one to three is 1017 MPa, and the elongation after fracture is 0.9%. This indicates that due to the dissolution of the ceramic reinforcing phase after solution quenching, the size and strength of the two titanium alloy matrix phases, namely primary α-Ti and quenched β-Ti, increase, resulting in deformation incoordination and brittle fracture below the yield point. Compared to Comparative Example 2, the room temperature tensile strength of the near-α titanium-based composite material plate prepared in Comparative Example 3 via steps one to three and step five via solution quenching is 1723 MPa, and the elongation after fracture is 1.7%. This indicates that the hot rolling strengthening effect (such as dislocation storage and recrystallization) causes the material to fracture after reaching the yield point, exhibiting higher strength. Compared to Comparative Example 2, the near-α titanium-based composite material of Comparative Example 4, prepared through steps one to four, exhibits a room temperature tensile strength of 1594 MPa and an elongation after fracture of 1.4%. This indicates that aging precipitates a large number of multi-scale reinforcing phases TiC and Ti5Si3, while the matrix structure transforms into a secondary α-Ti+β-Ti matrix phase with good plasticity and nanoscale size, encapsulating a primary α-Ti matrix phase with higher strength. This type of structure improves deformation incompatibility and exhibits higher strength. In contrast, the plate of the heat-treated solid solution coupled reinforced near-α titanium-based composite material prepared through steps one to five in Example 1 has a room temperature tensile strength of 1842 MPa and an elongation after fracture of 2.2%. This demonstrates that the present invention employs high-temperature solid solution heat treatment, aging heat treatment, and hot rolling process, utilizing the coupling effects of solid solution strengthening, dispersion strengthening, hot rolling strengthening, and heterogeneous structure to enable the material to exhibit extremely high strength and certain plasticity.

[0054] Example 2

[0055] This embodiment includes the following steps:

[0056] Step 1: Weigh 99.0% of TA11 near-α titanium-based powder, 0.1% of carbon black powder, 0.09% of TaC ceramic powder, and 0.81% of NbC ceramic powder by weight percentage. Place all the TA11 near-α titanium-based powder, half of the additives TaC and NbC ceramic powder, and carbon black powder in a stainless steel ball mill jar with a ball-to-powder ratio of 5:1. Use a planetary ball mill to ball-mill and mix at 150 rpm for 1 hour. Then add the remaining half of the additives TaC and NbC ceramic powder and carbon black powder, and ball-mill and mix at 150 rpm for 5 hours to obtain near-α titanium-based composite powder coated with carbon black and embedded with TaC and NbC ceramic powder on the surface.

[0057] Step 2: The near-α titanium-based composite powder obtained in Step 1, which is coated with carbon black and has TaC and NbC ceramic powder embedded on its surface, is placed into a graphite mold for discharge plasma sintering. The sintering temperature is 900℃, the sintering pressure is 45MPa, and the constant pressure and temperature are maintained for 5 minutes. After cooling in the furnace, the powder is demolded to obtain the sintered near-α titanium-based composite material.

[0058] Step 3: Place the sintered near-α titanium-based composite material obtained in Step 2 under gas protection and perform high-temperature solution heat treatment in a heat treatment furnace. The temperature of the high-temperature solution heat treatment is 900℃ and the holding time is 6h. Then, use water as a medium for quenching to obtain the solution-quenched near-α titanium-based composite material.

[0059] Step 4: The solution-quenched near-α titanium-based composite material obtained in Step 3 is placed under gas protection and subjected to aging heat treatment in a heat treatment furnace at a temperature of 400℃ for 6 hours, and then cooled with the furnace to obtain the aging near-α titanium-based composite material.

[0060] Step 5: The aged near-α titanium-based composite material obtained in Step 4 is hot-rolled at a temperature of 800℃ and a holding time of 5 minutes to obtain a plate of heat-treated solid solution coupled reinforced near-α titanium-based composite material.

[0061] Example 3

[0062] This embodiment includes the following steps:

[0063] Step 1: Weigh 98.0% of TA15 near-α titanium-based powder, 0.8% of carbon black powder, 1.08% of TaC ceramic powder, and 0.12% of NbC ceramic powder by weight percentage. Place all TA15 near-α titanium-based powder, half of the additives TaC and NbC ceramic powder, and carbon black powder in a stainless steel ball mill jar with a ball-to-powder ratio of 6:1. Use a planetary ball mill to ball-mill and mix at 250 rpm for 3 hours. Then add the remaining half of the additives TaC and NbC ceramic powder and carbon black powder, and ball-mill and mix at 250 rpm for 7 hours to obtain near-α titanium-based composite powder coated with carbon black and embedded with TaC and NbC ceramic powder on the surface.

[0064] Step 2: The near-α titanium-based composite powder obtained in Step 1, which is coated with carbon black and has TaC and NbC ceramic powder embedded on its surface, is placed into a graphite mold for discharge plasma sintering. The sintering temperature is 1100℃, the sintering pressure is 50MPa, and the constant pressure and temperature are maintained for 8 minutes. After cooling in the furnace, the powder is demolded to obtain the sintered near-α titanium-based composite material.

[0065] Step 3: The sintered near-α titanium-based composite material obtained in Step 2 is placed under gas protection and subjected to high-temperature solution heat treatment in a heat treatment furnace. The temperature of the high-temperature solution heat treatment is 1100℃ and the holding time is 12h. Then, oil is used as the medium for quenching to obtain the solution-quenched near-α titanium-based composite material.

[0066] Step 4: The solution-quenched near-α titanium-based composite material obtained in Step 3 is placed under gas protection and subjected to aging heat treatment in a heat treatment furnace at a temperature of 600℃ for 12 hours, and then cooled with the furnace to obtain the aging near-α titanium-based composite material.

[0067] Step 5: The near-α titanium-based composite material obtained in Step 4 is hot-rolled at a temperature of 1000℃ and a holding time of 8 minutes to obtain a plate of heat-treated solid solution coupled reinforced near-α titanium-based composite material.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing heat-treated solid solution coupled reinforced near-α titanium-based composite materials, characterized in that, The method includes the following steps: Step 1: Ball mill and mix near-α titanium-based powder with carbon black powder, TaC and NbC ceramic powder to obtain near-α titanium-based composite powder coated with carbon black and embedded with TaC and NbC ceramic powder on the surface; the near-α titanium-based powder is TA11, TA15 or TA19; the total mass percentage of the additives TaC and NbC ceramic powder and carbon black powder in the near-α titanium-based composite powder is 1%~2%, of which the mass percentage of carbon black powder is 0.1%~0.8%, and the mass ratio of TaC to NbC ceramic powder is 1:9~9:1; Step 2: The near-α titanium-based composite powder obtained in Step 1, which is coated with carbon black and has TaC and NbC ceramic powder embedded on its surface, is subjected to discharge plasma sintering to obtain a sintered near-α titanium-based composite material. Step 3: Place the sintered near-α titanium-based composite material obtained in Step 2 under vacuum or gas protection, and perform high-temperature solution heat treatment and quenching in a heat treatment furnace to obtain a solution-quenched near-α titanium-based composite material; the temperature of the high-temperature solution heat treatment is 900℃~1100℃, and the holding time is 6h~12h. Step 4: Place the solution-quenched near-α titanium-based composite material obtained in Step 3 under vacuum or gas protection, perform aging heat treatment in a heat treatment furnace, and then cool to obtain the aging near-α titanium-based composite material; the aging heat treatment temperature is 400℃~600℃, and the holding time is 6h~12h. Step 5: The near-α titanium-based composite material obtained in Step 4 is hot-rolled to obtain a plate of heat-treated solid solution coupled reinforced near-α titanium-based composite material; the hot rolling temperature is 800℃~1000℃ and the holding time is 5min~10min.

2. The method for preparing the heat-treated solid solution coupled reinforced near-α titanium-based composite material according to claim 1, characterized in that, The near-α titanium-based powder mentioned in step one is a spherical powder with a particle size of 15μm~53μm.

3. The method for preparing the heat-treated solid solution coupled reinforced near-α titanium-based composite material according to claim 1, characterized in that, The TaC ceramic powder mentioned in step one has particles with a particle size of 0.1μm to 1μm, and the NbC ceramic powder has particles with a particle size of 0.1μm to 1μm.

4. The method for preparing the heat-treated solid solution coupled reinforced near-α titanium-based composite material according to claim 1, characterized in that, The ball milling speed for the ball milling mixture described in step one is 150 rpm to 250 rpm, the ball-to-material ratio is 3 to 6:1, and the ball milling time is 6 to 10 hours. The ball milling mixture includes two stages: in the first stage, half of the additives TaC and NbC ceramic powder and carbon black powder are added, and the ball milling time is 1 to 3 hours; in the second stage, the remaining half of the additives TaC and NbC ceramic powder and carbon black powder are added, and the ball milling time is 5 to 7 hours.

5. The method for preparing the heat-treated solid solution coupled reinforced near-α titanium-based composite material according to claim 1, characterized in that, The discharge plasma sintering process described in step two is as follows: the near-α titanium-based composite powder, which is coated with carbon black and has TaC and NbC ceramic powder embedded on its surface, is placed in a graphite mold and kept at a constant pressure and temperature of 900℃~1100℃ and a sintering pressure of 40MPa~50MPa for 5min~10min.

6. The method for preparing the heat-treated solid solution coupled reinforced near-α titanium-based composite material according to claim 1, characterized in that, The quenching medium mentioned in step three is water or oil.

7. The method for preparing the heat-treated solid solution coupled reinforced near-α titanium-based composite material according to claim 1, characterized in that, The cooling method described in step four is furnace-side cooling.

8. A heat-treated solid solution coupled reinforced near-α-titanium-based composite material, characterized in that, Prepared by the method described in any one of claims 1 to 7.

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