A post-processing method for high strength and toughness modification of laser powder bed fused titanium-based composite materials

Abstract

The application relates to a post-treatment method for high strength and toughness modification of laser powder bed melting titanium-based composite materials, and relates to the field of metal matrix composites.The application aims to solve the problem of the mismatch between the strength and toughness of titanium-based composite materials at room temperature.The application selects a near-alpha titanium alloy or an alpha+beta dual-phase titanium alloy as a matrix to mix with a ceramic reinforcing phase to prepare a titanium-based composite material, carries out hot isostatic pressing treatment in an alpha+beta two-phase region, carries out solid solution aging treatment on the titanium-based composite material after the hot isostatic pressing, performs water cooling, then carries out aging treatment and carries out furnace cooling after the aging treatment.The application combines the hot isostatic pressing and the solid solution aging treatment to significantly improve the plasticity at room temperature while ensuring that the strength is almost not decreased, and realizes high density, high strength and high toughness of the titanium-based composite material.The application greatly improves the mechanical properties of the titanium-based composite material, improves the problem of the mismatch between the strength and toughness of the titanium-based composite material at room temperature, and has important significance for the wide application and popularization of the laser powder bed melting titanium-based composite material in engineering practice.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composites, specifically relating to a post-processing method for high-strength and tough modification of laser powder bed molten titanium matrix composites. Background Technology

[0002] Titanium-based composites, which introduce reinforcing phases into the titanium alloy matrix in situ, possess high specific strength, high specific stiffness, and excellent wear resistance, thermal stability, and high-temperature durability, making them promising candidate materials for key components in hypersonic aerospace vehicles and next-generation advanced aero engines. With the rapid development of the aerospace industry, the critical and complex components of aircraft place higher demands on forming accuracy and production efficiency. Traditional subtractive manufacturing struggles to achieve high-efficiency precision manufacturing of these complex components. Unlike traditional forming methods, laser additive manufacturing offers significant advantages such as extremely strong ability to form complex structures, extremely high forming accuracy, and rapid prototyping capabilities, and is considered one of the most promising manufacturing methods for complex and precision parts made of titanium alloys and titanium-based composites.

[0003] Laser additive manufacturing technology for forming high-strength titanium-based composite materials includes laser metal direct forming (LMDF) characterized by powder feeding and laser powder bed melting (LPBF) characterized by powder spreading, which are currently the most widely used methods. While LMDF can manufacture complex structures, its processing precision is not high. Laser powder bed melting, on the other hand, can achieve high-precision forming of complex structures with excellent mechanical properties, providing a good solution for manufacturing high-strength, complex, and precision structural components for aerospace vehicles. Compared to titanium alloys, laser powder bed melting titanium-based composites have finer martensitic structures and brittle reinforcing phases, exhibiting more typical characteristics of high strength and low plasticity. Generally, titanium-based composites formed by direct laser powder bed melting have a fracture elongation of less than 4% and poor room-temperature plasticity, making them unsuitable for practical applications. This is mainly because the poor room-temperature toughness of the material leads to a series of problems in practical engineering applications, such as: large-sized components are prone to deformation and cracking, making forming difficult; fatigue cracks are easily induced during service, leading to premature component failure; and weak impact resistance, where even small cracks can rapidly propagate within the material, causing catastrophic consequences. The high room-temperature brittleness of laser powder bed fused titanium matrix composites is mainly due to two factors: First, there is an inverse relationship between the strength and toughness of titanium matrix composites; increased strength leads to decreased plasticity. While the introduction of the ceramic phase has a significant grain-refining strengthening effect, as a typical brittle phase, it greatly reduces the material's plasticity. Second, the rapid cooling and heating process in additive manufacturing easily causes uneven microstructures, resulting in microscopic residual stress. The accumulation of residual stress greatly reduces the material's plasticity and can even lead to macroscopic cracking and delamination. Simultaneously, defects such as pores inevitably appear within the material during this process. These defects will generate significant stress concentrations during component service, becoming crack initiation sources and causing premature fracture, severely impacting the material's plasticity and service life. Therefore, achieving a better strength-toughness balance is crucial for the widespread application of laser powder bed fused titanium matrix composites, a typical high-strength, low-plasticity material, in engineering practice.

[0004] To achieve a superior balance between strength and toughness in laser powder bed fused titanium matrix composites (LBCs), namely, significantly improving plasticity while maintaining almost no decrease in material strength, appropriate post-treatment is necessary. Common post-treatment methods include annealing and hot isostatic pressing (HIP). Annealing involves the partial decomposition of martensite into α and β phases, as well as grain and reinforcing phase coarsening. While eliminating or reducing residual stress at defects in the metallic material and adjusting the content and distribution of the β phase, significantly improving its plasticity, its strength decreases substantially. HIP, although capable of eliminating porosity defects and increasing density with minimal deformation, and improving plasticity to some extent, involves almost complete decomposition of martensite into α and β phases. Furthermore, the coarsening of α phase lamellars and reinforcing phase size intensifies with increasing HIP temperature, making it difficult to retain the initial strength of the additive manufacturing material. Therefore, significantly improving plasticity without sacrificing strength is crucial for the practical application of LBCs.

[0005] CN 117620205 B, "A Preparation Method of Additively Manufactured Titanium Alloy," discloses a method for simultaneously optimizing the microstructure and porosity of a material by coupling and controlling these aspects. First, porosity within the printed material is eliminated through printing and hot isostatic pressing (HIP). Then, based on the critical temperature and time for grain growth and phase transformation, a short-term high-temperature heat treatment is applied to optimize the material's microstructure. This patent overcomes the technical barriers inherent in traditional printing processes, HIP, and heat treatment, such as unavoidable printing voids, lath coarsening, and grain boundary α-phase formation. Furthermore, it eliminates the need for meticulous optimization of the printing and HIP processes, enabling the convenient and rapid acquisition of additively manufactured titanium alloys with ultra-high fatigue strength, significantly saving costs and improving efficiency. It also clarifies the ultra-high fatigue resistance of additively manufactured microstructures, demonstrating the enormous potential of additive manufacturing technology in manufacturing fatigue-resistant structural components. However, this patented method is a treatment technique for improving the fatigue performance of titanium alloys. The final effect, namely the room temperature strength and toughness of the resulting material, is similar to that of materials obtained through traditional annealing—a significant decrease in strength followed by an increase in ductility. The method primarily focuses on designing a fatigue-resistant microstructure and does not elaborate on or offer any insights into improving the room temperature strength and toughness of titanium alloys. Furthermore, titanium alloys exhibit good room temperature ductility, and their inherent poor room temperature ductility does not present the engineering application difficulties associated with such properties. In contrast, during additive manufacturing, the introduction of reinforcing phases significantly alters the microstructure of titanium-based composites. Since microstructure determines performance, titanium-based composites exhibit a more typical problem of extremely high room temperature strength and extremely poor ductility—a mismatch between strength and ductility. The introduction of reinforcing phases fundamentally alters the corresponding strengthening and toughening mechanisms and deformation failure behaviors compared to titanium alloys. Therefore, the key to improving the high strength and toughness of titanium-based composites lies in understanding how to synergistically influence the morphology, size, and phase relationship of the matrix phase and the ceramic phase—that is, how to control the microstructure through appropriate post-processing methods to achieve the ultimate goal of excellent strength and toughness. Summary of the Invention

[0006] The purpose of this invention is to solve the problem of mismatch between room temperature strength and toughness in titanium-based composite materials, which makes it impossible to simultaneously improve room temperature toughness without reducing strength.

[0007] The present invention discloses a post-processing method for high-strength and toughness modification of laser powder bed molten titanium-based composite materials, the method comprising the following steps:

[0008] Step 1: Select near-α titanium alloy or α+β dual-phase titanium alloy as the matrix and mix it with ceramic reinforcing phase, then prepare titanium-based composite materials by laser powder bed melting technology;

[0009] Step 2: The obtained titanium-based composite material is subjected to hot isostatic pressing in the α+β two-phase region;

[0010] Step 3: After hot isostatic pressing, the titanium-based composite material is subjected to solution aging treatment and then water cooling, followed by furnace cooling after aging treatment; the solution treatment is carried out in the β single-phase region at a temperature of 1030-1200℃ for 6-10 min, and the aging treatment is carried out at a temperature of 500-700℃ for 4-8 h.

[0011] Furthermore, the ceramic reinforcing phase is one or more of TiB2, TiC, and ZrB2.

[0012] Furthermore, the mass fraction of the ceramic reinforcing phase in the titanium-based composite material is 0.2–0.8 wt.%.

[0013] Furthermore, the near-α titanium alloy is TA15 or TA24; the α+β dual-phase titanium alloy is TC4, TC6 or TC11.

[0014] Furthermore, the hot isostatic pressing conditions are: inert gas protective atmosphere, temperature 900-950℃, pressure 100-150MPa, holding time 2-4h, and heating rate 5-10℃ / min.

[0015] Furthermore, the temperature of the water-cooled water is 10–20°C.

[0016] Furthermore, the heating rate of the aging treatment is 5–10 °C / min.

[0017] Furthermore, the solution treatment is carried out in the β single-phase region at a temperature of 1050–1200 °C for 6–10 min.

[0018] Furthermore, the solution treatment is carried out in the β single-phase region at a temperature of 1050–1100 °C for 6–10 min.

[0019] Furthermore, the aging treatment temperature is 600–700℃, and the time is 4–8 hours.

[0020] The present invention has the following beneficial effects:

[0021] This invention overcomes the problem of inverse strength and plasticity in titanium-based composite materials by combining hot isostatic pressing and solution aging treatment. The material significantly improves room temperature plasticity while ensuring that the strength is almost not reduced, thus achieving high density, high strength and high toughness in titanium-based composite materials. Based on the room-temperature mechanical strengthening mechanism of titanium matrix composites, the grain refinement strengthening effect of the matrix and the load transfer strengthening effect of the reinforcing phase are the main influencing factors for maintaining the high strength of additively manufactured titanium matrix composites. The changes in the matrix phase content and the distribution of the reinforcing phase are key factors affecting the toughness of the material. Based on the above principles, the material is first subjected to hot isostatic pressing in the α+β two-phase region. This process can eliminate defects, especially pore defects, inside the material during laser powder bed melting, resulting in a uniform, stable and dense matrix structure. At the same time, it allows the reinforcing phase to grow fully. Within the selected hot isostatic pressing temperature range, the longitudinal growth trend of the reinforcing phase is greater than the transverse coarsening, which can achieve a significant increase in the aspect ratio. The reinforcing phase with a high aspect ratio can play a more significant load transfer strengthening role. However, at the same time, the α phase lamellae in the matrix structure are significantly coarsened during the hot isostatic pressing process, and the β phase precipitates to a greater extent between the α phases. The coarsening of the grain size means that the grain refinement strengthening effect is weakened. Excessive grain size and unsuitable phase content will affect the performance of the material. Therefore, further heat treatment is necessary. Solution treatment in the β single-phase region allows the material to regain a fine martensitic structure during rapid cooling. Simultaneously, the reinforcing phase no longer dispersed in the matrix but exhibits a network distribution along grain boundaries, effectively hindering dislocation slip. Experimental studies show that the lateral coarsening tendency of the reinforcing phase during heat treatment in the β single-phase region is much greater than its longitudinal growth. To retain the high aspect ratio reinforcing phase, a short-time solution aging strategy is adopted. By controlling the solution aging process parameters, the target microstructure is obtained—a microstructure with extremely fine grain size, high aspect ratio of the reinforcing phase, and appropriate phase content ratio—significantly improving the comprehensive mechanical properties of the titanium-based composite material. Using this method, the elongation of the titanium-based composite material can be increased from 3.6% to 10.3% without a significant decrease in strength, while the material density can reach over 99.99%. This greatly improves the mechanical properties of the titanium-based composite material and significantly addresses the mismatch between room temperature strength and toughness. This is of great significance for the widespread application and promotion of laser powder bed fusion titanium-based composite materials in engineering practice. Attached Figure Description

[0022] Figure 1 The room temperature tensile curve of TiB2 / TA15 composite material;

[0023] Figure 2 Macroscopic photograph of a TiB2 / TA15 composite material sample prepared by laser powder bed melting;

[0024] Figure 3Images showing the 3D-CT results of the TiB2 / TA15 composite material: (a) printed state; (b) post-processing state.

[0025] Figure 4 The microstructure results of the TiB2 / TA15 composite material are shown in the following figures: (a) Printed state; (b) Comparative Example 1; (c) Comparative Example 2; (d) Comparative Example 3; (ef) Example 1. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the spirit of the contents disclosed in the present invention will be described in detail below. After understanding the embodiments of the present invention, any person skilled in the art can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.

[0027] The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0028] Comparative Example 1

[0029] The specific steps of this comparative example are as follows: A near-α phase titanium alloy—TA15 (nominal composition Ti-6.5Al-2Zr-1Mo-1V)—was selected as the matrix, and titanium diboride (chemical formula TiB2) was selected as the reinforcing phase, with a TiB2 volume fraction of 0.85 vol.%. A 0.85 vol.% TiB2 / TA15 titanium-based composite material sample was prepared by laser powder bed melting. The obtained laser powder bed molten titanium-based composite material was subjected to annealing heat treatment with the following process parameters: holding temperature 800℃, holding time 2 h, and furnace cooling to room temperature.

[0030] Figure 1 The stress-strain curve of the titanium-based composite material after being held at 800℃ for 2 hours. Figure 1 The yield strength of the laser powder bed fused titanium matrix composite material after annealing heat treatment is 1110.4 MPa, the tensile strength is 1236.8 MPa, and the elongation is 7.9%. Although the elongation is improved while the strength is significantly reduced, the improvement is not significant.

[0031] Comparative Example 2

[0032] The specific steps of this comparative example are as follows: A near-α phase titanium alloy—TA15 (nominal composition Ti-6.5Al-2Zr-1Mo-1V) was selected as the matrix, and titanium diboride (chemical formula TiB2) was selected as the reinforcing phase, with a TiB2 volume fraction of 0.85 vol.%. A 0.85 vol.% TiB2 / TA15 titanium-based composite material sample was prepared by laser powder bed melting. The obtained laser powder bed molten titanium-based composite material was subjected to hot isostatic pressing (HIP) post-treatment with the following process parameters: holding temperature 920℃, holding time 3h, pressure 150MPa, and furnace cooling to room temperature.

[0033] Figure 1 The stress-strain curves of the titanium-based composite material after being held at 920℃ and 150MPa for 3 hours are shown. Figure 1 As shown, in Comparative Example 2, the yield strength of the laser powder bed molten titanium matrix composite material after only hot isostatic pressing treatment was 1019.2 MPa, the tensile strength was 1123.5 MPa, and the elongation was 16.0%. The plasticity of the material was significantly improved, but the strength decreased too much.

[0034] Comparative Example 3

[0035] The specific steps of this comparative example are as follows: A near-α phase titanium alloy—TA15 (nominal composition Ti-6.5Al-2Zr-1Mo-1V) was selected as the matrix, and titanium diboride (chemical formula TiB2) was selected as the reinforcing phase, with a TiB2 volume fraction of 0.85 vol.%. A 0.85 vol.% TiB2 / TA15 titanium-based composite material sample was prepared by laser powder bed melting. The obtained laser powder bed molten titanium-based composite material underwent solution treatment and aging. The solution treatment parameters were: holding temperature 1110℃, holding time 8 min, water cooling; the aging parameters were: holding temperature 600℃, holding time 4 h.

[0036] Figure 1 The stress-strain curves of titanium-based composite materials after solution treatment and aging are shown. Figure 1 The yield strength of the laser powder bed fused titanium matrix composite material after solution treatment and aging is 1149.4 MPa, the tensile strength is 1275.0 MPa, and the elongation is 8.8%. The material strength has decreased, and although the plasticity has improved compared with Comparative Example 1, the improvement effect is not ideal.

[0037] Example 1

[0038] This embodiment describes a post-processing method for high-strength and toughness modification of laser powder bed molten titanium-based composite materials, which is carried out according to the following steps:

[0039] (1) Near-α phase titanium alloy TA15 (nominal composition Ti-6.5Al-2Zr-1Mo-1V) was selected as the matrix, and titanium diboride (chemical formula TiB2) was selected as the reinforcing phase, wherein the volume fraction of TiB2 was 0.85 vol.%, and 0.85 vol.% TiB2 / TA15 titanium matrix composite sample was prepared by laser powder bed melting.

[0040] (2) The laser powder bed molten titanium-based composite material obtained in (1) was subjected to hot isostatic pressing to eliminate pore defects and fully stabilize the microstructure. The hot isostatic pressing process used high-purity argon as a protective atmosphere. The process parameters were: holding temperature 920℃, holding time 3h, pressure 150MPa, and furnace cooling, in order to obtain a uniform, stable and dense TiB2 / TA15 titanium-based composite material.

[0041] (3) The titanium-based composite material after hot isostatic pressing (2) was subjected to solution aging treatment to further regulate the matrix structure and the form and distribution of the reinforcing phase. The material was kept at 1110℃ for 8 min and then cooled with water for solution treatment to obtain fine martensite phase and achieve microstructure refinement. Then, it was kept at 600℃ for 4 h and cooled to room temperature in the furnace for aging treatment to further strengthen and improve plasticity, thereby obtaining a titanium-based composite material with significantly improved room temperature strength and plasticity. Figure 1 The comparison of the room temperature tensile properties of the post-processed composite material shows that, compared with the three comparative examples mentioned above, the titanium-based composite material obtained in this embodiment maintains a higher strength while being basically equivalent to that in the printed state. At the same time, the elongation is increased from 3.6% to 10.3%, which is an increase of 186%. This achieves the effect of almost no decrease in room temperature tensile strength while significantly improving toughness.

[0042] The internal three-dimensional porosity defects of composite materials prepared by laser powder bed melting and composite materials that have undergone post-processing control were observed. Figure 3 The 3D-CT test results of the printed and post-processed TiB / TA15 composite materials show that there are obvious millimeter-scale pore defects inside the printed material, while only a very small number of micron-scale pore defects exist after post-processing. In particular, the hot isostatic pressing process can almost completely close the pore defects inside the composite material. Although a small amount of pores reappear during solution treatment and aging, the density can still reach 99.99%, which is still significantly better than that of the printed state.

[0043] Figure 4 Images of the microstructure of titanium-based composite materials in the printed and post-processed states, such as... Figure 4As can be seen, unlike the coarsened microstructure easily obtained by traditional heat treatment, the titanium-based composite material obtained by the method of this invention still retains a fine martensitic microstructure, and the grain size is comparable to that in the printed state. Simultaneously, the nanoscale dispersed TiB whiskers undergo significant coarsening and grow in a network distribution along the grain boundaries during this process. At this point, the high aspect ratio TiB whiskers play a strong load-transfer strengthening role in the material. These characteristics allow the material to retain high strength. The control of the matrix phase content is key to improving the material's plasticity. This is mainly due to the partial decomposition of martensite to form α and β phases, increasing the β phase content in the matrix. Compared to the hcp structure of the α / α' phase, β-Ti has a typical bcc structure, providing more slip systems within the matrix, which is conducive to plastic deformation. Microstructure determines properties; a microstructure with fine grain size, high aspect ratio of the reinforcing phase, and appropriate phase content is beneficial for achieving excellent room-temperature strength-plasticity matching, which is of great significance for the practical application of titanium-based composite materials prepared by laser powder bed melting.

[0044] Example 2

[0045] This embodiment describes a post-processing method for high-strength and toughness modification of laser powder bed molten titanium-based composite materials, which is carried out according to the following steps:

[0046] (1) The 0.85 vol.% TiB2 / TA15 titanium-based composite material sample prepared by laser powder bed melting in Example 1 was subjected to hot isostatic pressing to eliminate pore defects and fully stabilize the microstructure. The hot isostatic pressing process used high-purity argon as a protective atmosphere. The process parameters were: holding temperature 920℃, holding time 3h, pressure 150MPa, furnace cooling, to obtain a dense titanium-based composite material.

[0047] (2) The titanium-based composite material after hot isostatic pressing (1) was subjected to solution aging treatment to further regulate the matrix structure and the form and distribution of the reinforcing phase. The material was solution treated by holding at 1050℃ for 8 min and then water-cooled to obtain fine martensite phase and refine the structure. Then, it was aged at 700℃ for 4 h and cooled to room temperature in the furnace to further strengthen and improve plasticity, thereby obtaining a titanium-based composite material with significantly improved room temperature strength and plasticity. Compared with the three comparative examples, at a strength level higher than or equivalent to them, the improved plasticity of this example is much higher than that of comparative examples 1 and 3. The elongation can be increased from 3.6% to 12.8%, which is an increase of 250%. Its toughness improvement effect is much better than that of comparative examples 1 and 3. At the same time, its comprehensive mechanical properties are better than those of comparative example 2, achieving more effective improvement in toughness.

[0048] In this embodiment, the control of the room temperature strength and toughness relationship of the material is mainly achieved by changing the solution aging parameters to adjust the content, composition, and morphology of the matrix phase and ceramic reinforcement. Comparative Example 1 uses traditional annealing, which results in excessively coarse grain size during the phase content control process, significantly reducing the original fine-grained strengthening effect. Comparative Example 2 is similar to Comparative Example 1; the hot isostatic pressing process, through thermo-pressing coupling, can significantly eliminate internal porosity defects and increase the aspect ratio of the reinforcing phase, but excessive coarsening of the microstructure also occurs during this process. Comparative Example 3, with its solution aging treatment, maintains a fine grain size during rapid cooling, but the TiB whiskers are difficult to grow during short-term holding in the β single-phase region, making it impossible to obtain a reinforcing phase with a high aspect ratio. Using this post-treatment method, the problems encountered in the above common heat treatments can be avoided, resulting in a microstructure with extremely fine grain size, a high aspect ratio of the reinforcing phase, and an appropriate phase content ratio. The size of martensite and TiB whiskers can be controlled primarily by altering solid solution parameters, resulting in finer martensite and TiB whiskers with a larger aspect ratio. During this process, TiB segregates at grain boundaries, forming a network that hinders dislocation slip. These structural changes effectively ensure the material's high strength. Aging parameters, on the other hand, primarily control the β-phase content and α-phase lamellar size in the matrix, providing possibilities for achieving high plasticity. With increasing aging temperature, more martensite in the matrix decomposes into α and β phases, with the β-phase content gradually increasing. Simultaneously, the α-lamellae and TiB whiskers gradually coarsen. At an aging temperature of 700℃, a significant amount of β-phase precipitates between the α-lamellae, increasing the β-phase content and providing more possibilities for plastic deformation. Furthermore, at this aging temperature, the coarsening of the α-phase lamellars and TiB whiskers remains within acceptable limits. As can be seen from Table 1, compared with the printed state, the titanium-based composite material obtained in this embodiment has an elongation of 250%, which is 3.6% to 12.8%, within an acceptable range of strength reduction, achieving a good room temperature strength-plasticity match.

[0049] Table 1 TiB 2 / Room temperature tensile properties of TA15 composite material

[0050]

[0051]

Claims

1. A post-processing method for high-strength and toughness modification of laser powder bed molten titanium-based composite materials, characterized in that, The method is performed according to the following steps: Step 1: Select near-α titanium alloy or α+β dual-phase titanium alloy as the matrix and mix it with ceramic reinforcing phase, then prepare titanium-based composite materials by laser powder bed melting technology; Step 2: The obtained titanium-based composite material is subjected to hot isostatic pressing in the α+β two-phase region; Step 3: The titanium-based composite material after hot isostatic pressing is solution-treated and then water-cooled, followed by aging treatment and furnace cooling. The solution treatment is carried out in the β single-phase region at a temperature of 1030~1200℃ for 6~10 min, and the aging treatment is carried out at a temperature of 500~700℃ for 4~8 h. The mass fraction of ceramic reinforcing phase in the titanium-based composite material is 0.2~0.8 wt.%. The hot isostatic pressing conditions are: inert gas protective atmosphere, temperature 900~950℃, pressure 100~150 MPa, holding time 2~4 h, and heating rate 5~10℃ / min. The cooling water temperature for water cooling is 10~20℃. The heating rate for aging treatment is 5~10℃ / min.

2. The post-processing method for high-strength and toughness modification of laser powder bed molten titanium-based composite materials according to claim 1, characterized in that, The ceramic reinforcing phase is one or more of TiB2, TiC, and ZrB2.

3. The post-processing method for high-strength and toughness modification of laser powder bed molten titanium-based composite materials according to claim 1, characterized in that, The near-α titanium alloy is TA15 or TA24; the α+β dual-phase titanium alloy is TC4, TC6 or TC11.

4. The post-processing method for high-strength and toughness modification of laser powder bed molten titanium-based composite materials according to claim 1, characterized in that, The solution treatment is carried out in the β single-phase region at a temperature of 1050~1200℃ for 6~10 min.

5. A post-processing method for high-strength and toughness modification of laser powder bed molten titanium-based composite materials according to claim 1 or 4, characterized in that, The solution treatment is carried out in the β single-phase region at a temperature of 1050~1100℃ for 6~10 min.

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