Method for strengthening and toughening titanium matrix composite based on high temperature plastic deformation

Abstract

The application relates to a method for realizing strengthening and toughening of a titanium-based composite material based on high-temperature plastic deformation, comprising the following steps: according to a drawn flow stress and strain relation diagram under deformation temperature and strain rate conditions corresponding to a 30-60% deformation degree, calculating a titanium-based composite material sample deformation energy dissipation rate value eta and a non-stable flow parameter value zeta, and superimposing energy dissipation rate isogram and non-stable flow parameter distribution diagrams drawn respectively under different deformation temperature and strain rate conditions, so as to obtain optimal deformation temperature and strain rate of high-temperature plastic deformation of the titanium-based composite material sample. The application can realize the purposes of strengthening and toughening after high-temperature plastic deformation of the titanium-based composite material, and can be applied to the regulation of mechanical properties of various titanium-based composite materials.

Description

Technical Field

[0001] This invention relates to the field of metal matrix composites, and more particularly to a method for reinforcing and toughening ceramic phase-reinforced titanium matrix composites. Background Technology

[0002] With the continuous development of the aerospace industry, the harsh service environment of high-end equipment poses severe challenges to the ultra-high load-bearing capacity, extreme heat resistance, ultra-lightweight design, and high reliability of metallic structural materials. Ceramic-reinforced titanium matrix composites are metal matrix composites formed by in-situ synthesis or external addition of hard ceramic phases to a titanium alloy matrix. Compared with the matrix titanium alloy, their service temperature can be increased by 100–200°C, demonstrating great application potential in the aerospace field. On the one hand, the ceramic phase in titanium matrix composites achieves reinforcement through load transfer; on the other hand, the addition of the reinforcing phase can effectively refine the grain size of the matrix titanium alloy, further strengthening the titanium matrix composite. However, the increase in strength of ceramic-reinforced titanium matrix composites is often accompanied by a decrease in plasticity.

[0003] To improve the room-temperature brittleness of titanium matrix composites, scholars at home and abroad have studied methods such as controlling the distribution of reinforcing phases and reducing the size of reinforcing phases. However, the plasticity of most titanium matrix composites is still lower than that of titanium alloy matrices without reinforcing phases. Reference 1, "Li Qiang et al. Simultaneous enhancements of strength, ductility, and toughness in a TiB reinforced titanium matrix composite[J], Acta Mater, 2023, 254; 118995," prepared TiB reinforced titanium matrix composites using powder metallurgy, which improved their strength, plasticity, and fracture initiation toughness. This is mainly because the reinforcing phase particles are micron-sized and distributed within the grains, but this limits the widespread application of this method.

[0004] As is well known, plastic deformation is one of the effective ways to improve the microstructure and mechanical properties of metallic structural materials. Chinese Invention Patent 1, "Zhou Hao, Pan Zhiyi, Gao Bo, Lai Qingquan, Chen Xuefei, Cao Yang, Li Yusheng. A processing method for controlling the ductility and toughness of dual-phase steel by surface strong plastic deformation," publication number: CN110863084B, discloses a five-step process for controlling the ductility and toughness of dual-phase steel using surface strong plastic deformation: homogenization, first critical zone quenching, cold rolling, surface shot peening, and second critical zone quenching. The rolling and shot peening methods utilize the difference in strain between the surface and core to form dual-phase microstructures with different morphologies and distributions during heat treatment, thereby producing high-strength, high-toughness dual-phase steel that achieves both surface toughness and core strength, exhibiting excellent comprehensive performance. However, this method is mainly applicable to dual-phase steel and cannot be extended to other materials, especially single-phase materials.

[0005] Ceramic-reinforced titanium matrix composites are typical difficult-to-deform metallic materials, characterized by high deformation resistance and a narrow hot plastic deformation window. Reference 2, "YKCao,Y.Liu,YPLi,etal.Hot deformation behavior of nano-sized TiB reinforced Ti-6Al-4V metal matrix composites[J],Mech Mater,2020,141:103260," points out that when deformation process parameters are not properly selected, the ceramic reinforcing phase in ceramic-reinforced titanium matrix composites will debond and fracture even during high-temperature deformation, thus losing the reinforcing effect of the ceramic reinforcing phase. Furthermore, it can lead to unstable plastic flow in the ceramic-reinforced titanium matrix composites, failing to achieve the goal of controlling the mechanical properties of ceramic-reinforced titanium matrix composites using plastic deformation methods. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for strengthening and toughening titanium-based composite materials by means of high-temperature plastic deformation within an optimized high-temperature plastic deformation process window.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for strengthening and toughening titanium-based composite materials based on high-temperature plastic deformation, comprising the following steps:

[0008] Step 1: Under different deformation temperatures and strain rates, the titanium-based composite material samples are subjected to high-temperature plastic deformation treatment to obtain the flow stress and strain relationship of the titanium-based composite material samples when the deformation degree is 30-60%.

[0009] Step 2: Plot the flow stress-strain relationship diagram under the deformation temperature and strain rate conditions corresponding to any of the aforementioned deformation degrees. Then, based on the flow stress value σ and strain rate value in the flow stress-strain relationship diagram... The strain rate sensitivity index m, deformation energy dissipation rate η, and unsteady flow parameter ζ of the titanium-based composite material specimen were calculated sequentially; and plotted respectively:

[0010] Contour plots of energy dissipation rate under different deformation temperatures and strain rates;

[0011] Distribution of unsteady flow parameters under different deformation temperatures and strain rates;

[0012] Step 3: Overlay the energy dissipation rate contour map and the unstable flow parameter distribution map, and select the region in the overlay map where the energy dissipation rate value η is 0.4 to 0.7 and the unstable flow parameter value ζ is greater than 0. The deformation temperature and strain rate corresponding to the region are the optimal process window for high-temperature plastic deformation of the toughened titanium-based composite material sample.

[0013] Furthermore, the high-temperature plastic deformation treatment of the titanium-based composite material sample in step one is: isothermal compression deformation treatment using a thermal simulation compression testing machine. The titanium-based composite material sample used is a cylindrical titanium-based composite material sample with a smooth surface obtained by machining. A thermocouple is welded to the surface of the titanium-based composite material sample and then placed in the thermal simulation compression testing machine for isothermal compression deformation treatment.

[0014] The high-temperature plastic deformation treatment conditions involve heating to 750–850°C at a rate of 10–20°C / s, then further heating to the deformation temperature of 900–1050°C at a rate of 5–15°C / s, holding at that temperature for 1–5 minutes, and then loading the material with a strain rate of 0.001–5 s. -1 .

[0015] Furthermore, the cylindrical diameter of the titanium-based composite material sample is 8-10 mm, and the height is 12-15 mm; the surface of the titanium-based composite material sample is obtained by machining, placing it in anhydrous ethanol, then ultrasonically vibrating and cleaning it for 5-15 minutes, and then drying it.

[0016] Furthermore, the formula for calculating the strain rate sensitivity index value m is as follows:

[0017]

[0018] In the formula, σ is the flow stress value. This represents the strain rate value.

[0019] Then, the deformation energy dissipation rate η and the unsteady flow parameter ζ are calculated using Formula 2 and Formula 3, respectively:

[0020]

[0021]

[0022] Furthermore, step four includes a testing and verification step for strengthening and toughening the titanium-based composite material, specifically:

[0023] Step A: Under the optimal deformation temperature and strain rate conditions, the titanium-based composite material sample is subjected to high-temperature plastic deformation treatment;

[0024] Step B: On the titanium-based composite material sample that has undergone high-temperature plastic deformation, a plate-shaped tensile titanium-based composite material sample is processed with a gauge length of 10-15 mm, a width of 2-4 mm, and a thickness of 1-2 mm. A room temperature tensile test is then performed on an electronic universal testing machine.

[0025] Furthermore, the high-temperature plastic deformation treatment of the titanium-based composite material sample in step A is a free forging treatment. The titanium-based composite material sample used is a cylindrical titanium-based composite material sample cut from the titanium-based composite material. After the surface of the cylindrical titanium-based composite material sample is polished, a glass lubricant is applied. Then, it is placed in a box furnace and heated to the optimal deformation temperature range. After holding at this temperature for 10 to 30 minutes, it is placed in a hydraulic press for high-temperature plastic deformation treatment within 30 to 50 seconds to achieve a deformation degree of 30 to 50% of the titanium-based composite material sample.

[0026] Furthermore, the titanium-based composite material sample used in step A is a cylindrical sample with a diameter of 20-50 mm and a height of 20-50 mm cut from the titanium-based composite material.

[0027] Furthermore, the titanium-based composite material sample has TiB particles, whiskers, or TiC particles as the reinforcing phase, and the volume fraction of the reinforcing phase is 1-7 vol.%; the titanium alloy matrix of the titanium-based composite material is Ti6242, Ti55, or Ti65 alloy.

[0028] Furthermore, the titanium-based composite material sample is a Ti55 composite material reinforced with a reinforcing phase volume fraction of 3-7 vol.% TiB whiskers;

[0029] The high-temperature plastic deformation treatment described in step one uses isothermal compression deformation treatment performed on a thermal simulation compression testing machine: the temperature is increased to 800℃ at a rate of 20℃ / s, then increased to the deformation temperature at a rate of 10℃ / s, held at that temperature for 5 minutes, and then loaded. The deformation temperatures are 920℃, 950℃, 980℃, and 1010℃, and the strain rate is 0.001s. -1 0.01s -1 0.1s-1 and 1.0s -1 The deformation degree of the titanium-based composite material sample was 50%.

[0030] Furthermore, the titanium-based composite material sample is a 3.5 vol.% TiB whisker-reinforced Ti55 composite material;

[0031] The high-temperature plastic deformation treatment described in step one uses isothermal compression deformation treatment performed on a thermal simulation compression testing machine: the temperature is increased to 800℃ at a rate of 20℃ / s, then increased to the deformation temperature at a rate of 10℃ / s, held at that temperature for 5 minutes, and then loaded. The deformation temperatures are 920℃, 950℃, 980℃, and 1010℃, and the strain rate is 0.001s. -1 0.01s -1 0.1s -1 and 1.0s -1 The deformation degree of the titanium-based composite material sample was 30%.

[0032] The beneficial effects of this invention are: by calculating the energy dissipation rate and unstable flow parameters of titanium-based composites during high-temperature plastic deformation using isothermal compressive stress-strain curves, the high-temperature plastic deformation process window of titanium-based composites is optimized, so that the titanium-based composites can achieve both strengthening and toughening after high-temperature plastic deformation. Furthermore, the method of achieving strengthening and toughening of titanium-based composites using high-temperature plastic deformation can be applied to the control of the mechanical properties of various titanium-based composites. Attached Figure Description

[0033] Figure 1 The 7 vol.% TiBw / Ti55 composite material of Example 1 of this invention was subjected to deformation at a temperature of 980°C and a strain rate of 0.1 s⁻¹. -1 The isothermal compressive flow stress-strain curves obtained when the deformation degree is 50%;

[0034] Figure 2 This is a contour plot of the high-temperature plastic deformation energy dissipation rate of the 7 vol.% TiBw / Ti55 composite material in Example 1 of the present invention.

[0035] Figure 3 This is a distribution diagram of the unstable flow parameters during high-temperature plastic deformation of the 7 vol.% TiBw / Ti55 composite material in Example 1 of the present invention;

[0036] Figure 4 This is a superimposed diagram of the contour map of the high-temperature plastic deformation energy dissipation rate and the distribution map of the unstable flow parameters of the 7 vol.% TiBw / Ti55 composite material in Example 1 of the present invention.

[0037] Figure 5The tensile engineering stress-strain curve of the 3.5 vol.% TiBw / Ti55 composite material of Example 2 of the present invention after high-temperature plastic deformation;

[0038] Figure 6 The tensile engineering stress-strain curve of the 3.5 vol.% TiBw / Ti55 composite material of Example 2 of the present invention without high-temperature plastic deformation is shown. Detailed Implementation

[0039] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0040] Titanium-based composites prepared by adding ceramic phases to a titanium alloy matrix often exhibit reduced plasticity while significantly improving strength. High-temperature plastic deformation is one of the effective methods to improve the microstructure and mechanical properties of materials. However, ceramic-reinforced titanium-based composites are typical difficult-to-deform metallic materials. Deforming them within an inappropriate plastic deformation process window not only destroys the reinforcement effect but also causes unstable plastic flow, thus failing to achieve the goal of improving their mechanical properties through high-temperature plastic deformation. This has led to significant challenges in strengthening and toughening ceramic-reinforced titanium-based composites. Therefore, how to select a reasonable plastic deformation window for processing ceramic-reinforced titanium-based composites and how to ensure that reinforcement and toughening of ceramic-reinforced titanium-based composites can be achieved during high-temperature plastic deformation have become urgent technical problems to be solved.

[0041] To achieve the above objectives, the present invention provides the following specific embodiments:

[0042] Example 1: A method for strengthening and toughening titanium-based composite materials based on high-temperature plastic deformation, comprising the following steps:

[0043] Step 1: Under different deformation temperatures and strain rates, the titanium-based composite material samples are subjected to high-temperature plastic deformation treatment to obtain the flow stress and strain relationship of the titanium-based composite material samples when the deformation degree is 30-60%.

[0044] The high-temperature plastic deformation treatment of the titanium-based composite material sample is as follows: isothermal compression deformation treatment using a thermal simulation compression testing machine. The titanium-based composite material sample is a cylindrical sample with a smooth surface obtained by machining. A thermocouple is welded to the surface of the titanium-based composite material sample before it is placed in the thermal simulation compression testing machine for isothermal compression deformation treatment. The cylindrical diameter of the titanium-based composite material sample is 8-10 mm, and the height is 12-15 mm. The surface of the titanium-based composite material sample is obtained by machining, placing it in anhydrous ethanol, then ultrasonically vibrating and cleaning for 5-15 minutes, and then drying it.

[0045] The high-temperature plastic deformation treatment conditions involve heating to 750–850°C at a rate of 10–20°C / s, then further heating to the deformation temperature of 900–1050°C at a rate of 5–15°C / s, holding at that temperature for 1–5 minutes, and then loading the material with a strain rate of 0.001–5 s. -1 .

[0046] Step 2: Plot the flow stress-strain relationship diagram under the deformation temperature and strain rate conditions corresponding to any of the aforementioned deformation degrees. Then, based on the flow stress value σ and strain rate value in the flow stress-strain relationship diagram... The strain rate sensitivity index m, deformation energy dissipation rate η, and unsteady flow parameter ζ of the titanium-based composite material specimen were calculated sequentially.

[0047] The formula for calculating the strain rate sensitivity index value m is:

[0048]

[0049] In the formula, σ is the flow stress value. This represents the strain rate value.

[0050] Then, the deformation energy dissipation rate η and the unsteady flow parameter ζ are calculated using Formula 2 and Formula 3, respectively:

[0051]

[0052]

[0053] And draw them separately:

[0054] Contour plots of energy dissipation rate under different deformation temperatures and strain rates;

[0055] Distribution of unsteady flow parameters under different deformation temperatures and strain rates;

[0056] Step 3: Overlay the energy dissipation rate contour map and the unstable flow parameter distribution map, and select the region in the overlay map where the energy dissipation rate value η is 0.4 to 0.7 and the unstable flow parameter value ζ is greater than 0. The deformation temperature and strain rate corresponding to the region are the optimal process window for high-temperature plastic deformation of the toughened titanium-based composite material sample.

[0057] Step four, the testing and verification of the strengthening and toughening of titanium-based composite materials, specifically includes:

[0058] Step A: Under the optimal deformation temperature and strain rate conditions, the titanium-based composite material sample is subjected to high-temperature plastic deformation treatment;

[0059] The high-temperature plastic deformation treatment of the titanium-based composite material specimens is a free forging process. The titanium-based composite material specimens used are cylindrical specimens cut from the titanium-based composite material. After the surface of the cylindrical specimens is machined and coated with glass lubricant, they are placed in a box furnace and heated to the optimal deformation temperature range. After holding at this temperature for 10–30 minutes, they are placed in a hydraulic press for 30–50 seconds to achieve a high-temperature plastic deformation treatment with a deformation degree of 30–50%. The titanium-based composite material specimens used are cylindrical specimens with a diameter of 20–50 mm and a height of 20–50 mm cut from the titanium-based composite material.

[0060] Step B: On the titanium-based composite material sample that has undergone high-temperature plastic deformation, a plate-shaped tensile titanium-based composite material sample is processed with a gauge length of 10-15 mm, a width of 2-4 mm, and a thickness of 1-2 mm. A room temperature tensile test is then performed on an electronic universal testing machine.

[0061] The titanium-based composite material sample has TiB particles, whiskers or TiC particles as the reinforcing phase, and the volume fraction of the reinforcing phase is 1 to 7 vol.%; the titanium alloy matrix of the titanium-based composite material is Ti6242, Ti55 or Ti65 alloy.

[0062] Example 2: Same as Example 1, except that the titanium-based composite material sample is a Ti55 composite material reinforced with TiB whiskers with a volume fraction of 3-7 vol.% of the reinforcing phase;

[0063] The high-temperature plastic deformation treatment described in step one uses isothermal compression deformation treatment performed on a thermal simulation compression testing machine: the temperature is increased to 800℃ at a rate of 20℃ / s, then increased to the deformation temperature at a rate of 10℃ / s, held at that temperature for 5 minutes, and then loaded. The deformation temperatures are 920℃, 950℃, 980℃, and 1010℃, and the strain rate is 0.001s. -1 0.01s -1 0.1s -1 and 1.0s-1 The deformation degree of the titanium-based composite material sample was 50%.

[0064] Experimental Example 1: Figure 1-4 As shown, a method for strengthening and toughening titanium-based composite materials based on high-temperature plastic deformation includes the following steps:

[0065] Step 1: Cut a cylindrical titanium-based composite material sample with a diameter of 8 mm and a height of 12 mm from a Ti55 composite material reinforced with TiB whiskers (7.0 vol.% TiBw) at a volume fraction of 7.0%. After surface polishing, place the sample in anhydrous ethanol, clean it with ultrasonic vibration for 10 min, and then blow it dry to obtain a titanium-based composite material sample with a smooth surface.

[0066] Step 2, Isothermal Compression Deformation Test of 7.0 vol.% TiBw / Ti55 Composite Material: Thermocouples were welded onto the surface of the cylindrical titanium matrix composite material specimen and placed in a thermal simulation compression testing machine. The temperature was increased to 800℃ at 20℃ / s, then increased to the deformation temperature at 10℃ / s. After holding at this temperature for 5 minutes, loading was applied. The deformation temperatures were 920℃, 950℃, 980℃, and 1010℃, and the strain rate was 0.001 s⁻¹. -1 0.01s -1 0.1s -1 and 1.0s -1 The deformation reached 50%, and isothermal compressive flow stress-strain curves of titanium-based composite materials at the above deformation temperatures and strain rates corresponding to a deformation degree of 50% were plotted sequentially, such as... Figure 1 The figure shows a deformation temperature of 980℃ and a strain rate of 0.1s. -1 Isothermal compressive flow stress-strain curves of titanium-based composite materials with a deformation degree of 50%.

[0067] Step 3: Calculate the optimal high-temperature plastic deformation process window for the 7.0 vol.% TiBw / Ti55 composite material: Based on the deformation temperatures corresponding to 50% deformation, which are 920℃, 950℃, 980℃, and 1010℃, and the strain rate is 0.001 s⁻¹. -1 0.01s -1 0.1s -1 and 1.0s -1 Flow stress σ and strain rate under the given conditions Calculate the strain rate sensitivity index *m* of the 7 vol.% TiBw / Ti55 composite material. Based on this, calculate the high-temperature plastic deformation energy dissipation rate *η* and the unsteady flow parameter *ζ* of the 7 vol.% TiBw / Ti55 composite material according to formulas 2 and 3, respectively. Then, plot the energy dissipation rate contour map and the unsteady flow parameter distribution map, as shown below. Figure 2 and3 As shown, and will Figure 2 and Figure 3 The resulting overlay image is as follows: Figure 4 As shown, in Figure 4 The region selected has an energy dissipation rate greater than 0.45 and unsteady flow parameter values ​​greater than 0, such as... Figure 4 The area indicated by the red dashed box represents the optimal high-temperature plastic deformation process window for the titanium-based composite material: a deformation temperature of 960–1000℃ and a strain rate of 0.001–0.01 s⁻¹. -1 .

[0068] Step 4, Testing and verification of the toughening of 7.0 vol.% TiBw / Ti55 composite material: A cylindrical titanium-based composite material sample with a diameter of 30 mm and a height of 30 mm was cut from the titanium-based composite material. After the surface of the titanium-based composite material sample was polished, a glass lubricant was applied. The titanium-based composite material with the glass lubricant was placed in a box furnace and heated to the temperature range of the optimal process window and held for 15 min. Then the titanium-based composite material was taken out of the box furnace and placed in a hydraulic press. The high-temperature plastic deformation of the titanium-based composite material within 50 s resulted in a deformation degree of 50%.

[0069] Plate-shaped tensile titanium matrix composite specimens (gauge length 13.5 mm, width 3 mm, thickness 1.5 mm) were processed onto the titanium matrix composite specimens after high-temperature plastic deformation, and room temperature tensile tests were conducted on an Instron 3382 electronic universal testing machine. The tensile strength of the titanium matrix composite material formed in this embodiment was found to be 1282 MPa, and the ultimate elongation was 1.7%.

[0070] 7.0 vol.% TiBw / Ti55 composite material without high-temperature plastic deformation was processed into plate-shaped tensile titanium matrix composite specimens (gauge length 13.5 mm, width 3 mm, thickness 1.5 mm) and subjected to room temperature tensile tests on an Instron 3382 electronic universal testing machine. The results showed that the tensile strength of the titanium matrix composite material without high-temperature plastic deformation was 1049 MPa, and the ultimate elongation was 1.3%. This indicates that the present invention achieves the strengthening and toughening of the titanium matrix composite material using a high-temperature plastic deformation method.

[0071] Example 3: Same as Example 1, except that the titanium-based composite material sample is a 3.5 vol.% TiB whisker-reinforced Ti55 composite material;

[0072] The high-temperature plastic deformation treatment described in step one uses isothermal compression deformation treatment performed on a thermal simulation compression testing machine: the temperature is increased to 800℃ at a rate of 20℃ / s, then increased to the deformation temperature at a rate of 10℃ / s, held at that temperature for 5 minutes, and then loaded. The deformation temperatures are 920℃, 950℃, 980℃, and 1010℃, and the strain rate is 0.001s. -1 0.01s -1 0.1s -1 and 1.0s -1 The deformation degree of the titanium-based composite material sample was 30%.

[0073] Experimental Example 2: Figure 5 , 6 As shown, this experiment is the same as Experiment 1, except that it includes the following steps:

[0074] Step 1: Cut a cylindrical titanium-based composite material sample with a diameter of 8 mm and a height of 12 mm from the Ti55 composite material reinforced with TiB whiskers (3.5 vol.% TiBw) with a volume fraction of 3.5%. After surface polishing, place it in anhydrous ethanol, clean it with ultrasonic vibration for 10 min, and then blow it dry to obtain a titanium-based composite material sample with a smooth surface.

[0075] Step 2, Isothermal Compression Deformation Test of 3.5 vol.% TiBw / Ti55 Composite Material: Thermocouples were welded onto the surface of the cylindrical titanium matrix composite material specimens and placed in a thermal simulation compression testing machine. The temperature was increased to 800℃ at 20℃ / s, then increased to the deformation temperature at 10℃ / s. After holding at this temperature for 5 minutes, loading was applied. The deformation temperatures were 920℃, 950℃, 980℃, and 1010℃, and the strain rate was 0.001 s⁻¹. -1 0.01s -1 0.1s -1 and 1.0s -1 The deformation degree reached 30%, and the isothermal compressive flow stress-strain curves of titanium-based composite materials at the above deformation temperatures and strain rates corresponding to the deformation degree of 30% were plotted in sequence.

[0076] Step 3, Optimal high-temperature plastic deformation process window for 3.5 vol.% TiBw / Ti55 composite material: Based on the flow stress value σ and strain rate value in the flow stress-strain curve under the deformation temperature and strain rate conditions corresponding to a deformation degree of 30%. The strain rate sensitivity index *m* of the 3.5 vol.% TiBw / Ti55 composite material was calculated. Based on this, the high-temperature plastic deformation energy dissipation rate *η* and the unsteady flow parameter *ζ* of the 3.5 vol.% TiBw / Ti55 composite material were calculated according to formulas 2 and 3, respectively. Then, an energy dissipation rate distribution map and an unsteady flow parameter contour map were plotted. By overlaying the energy dissipation rate distribution map and the unsteady flow parameter contour map, the region with an energy dissipation rate greater than 0.45 and an unsteady flow parameter greater than 0 was selected from the overlay map. The optimal high-temperature plastic deformation process window for the titanium-based composite material was obtained as follows: deformation temperature of 940–980℃ and strain rate of 0.001–0.01 s⁻¹. -1 .

[0077] Step 4, Strengthening and toughening of 3.5 vol.% TiBw / Ti55 composite material: A cylindrical titanium-based composite material sample with a diameter of 30 mm and a height of 30 mm is cut from the titanium-based composite material. The surface of the titanium-based composite material sample is machined and then coated with glass lubricant. The titanium-based composite material coated with glass lubricant is placed in a box furnace and heated to the temperature range of the optimal process window and held for 15 min. Then the titanium-based composite material is taken out of the box furnace and placed in a hydraulic press. The high-temperature plastic deformation of the titanium-based composite material is completed within 30 s, so that its deformation degree is 30%.

[0078] Plate-shaped tensile titanium matrix composite specimens (gauge length 13.5 mm, width 3 mm, thickness 1.5 mm) were machined onto the titanium matrix composite specimens after high-temperature plastic deformation. Room temperature tensile tests were then performed on an Instron 3382 electronic universal testing machine. The resulting tensile stress-strain curves of the titanium matrix composites are shown below. Figure 5 As shown, the titanium-based composite material formed in this embodiment has a tensile strength of 1209 MPa and an ultimate elongation of 3.7%, as tested.

[0079] Plate-shaped tensile titanium matrix composite specimens (gauge length 13.5 mm, width 3 mm, thickness 1.5 mm) without high-temperature plastic deformation were processed and subjected to room-temperature tensile tests on an Instron 3382 electronic universal testing machine. The resulting tensile engineering stress-strain curves of the titanium matrix composite without high-temperature plastic deformation are shown below. Figure 6 As shown. Testing revealed that the tensile strength of the titanium-based composite material without high-temperature plastic deformation was 1052 MPa, and the ultimate elongation was 3.3%. This indicates that the present invention achieves the strengthening and toughening of the titanium-based composite material using a high-temperature plastic deformation method.

[0080] Example 4: Same as Example 1, except that the high-temperature plastic deformation treatment in step four is: isothermal compression deformation treatment performed using a thermal simulation compression testing machine.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for strengthening and toughening of a titanium-based composite material based on high-temperature plastic deformation, characterized in that, Comprising the following steps: Step one, under different deformation temperature and strain rate conditions, the titanium-based composite sample is subjected to high temperature plastic deformation treatment, so as to obtain the flow stress and strain relationship of the titanium-based composite sample when the deformation degree of the titanium-based composite material is 30-60%; The high temperature plastic deformation treatment of the titanium-based composite sample is isothermal compression deformation treatment using a thermal simulation compression testing machine, the titanium-based composite sample used is a cylindrical titanium-based composite sample obtained by mechanical processing and having a smooth surface, and a thermocouple is welded on the surface of the titanium-based composite sample and then placed in the thermal simulation compression testing machine for isothermal compression deformation treatment; and the high-temperature plastic deformation treatment condition is to heat to 750-850℃ at 10-20℃ / s, then to heat to deformation temperature 900-1050℃ at 5-15℃ / s, keep for 1-5min, then load, strain rate is 0.001-5s -1 ; Step 2: Plot the flow stress-strain relationship diagram under the deformation temperature and strain rate conditions corresponding to any of the aforementioned deformation degrees. Then, based on the flow stress values ​​in the flow stress-strain relationship diagram... and strain rate value The strain rate sensitivity index value m and the deformation energy dissipation rate value of the titanium-based composite material specimen were calculated sequentially. The values ​​of the unsteady flow parameter ζ are plotted separately. The energy dissipation rate contour map under different deformation temperature and strain rate conditions; The non-steady flow parameter distribution map under different deformation temperature and strain rate conditions; The calculation formula (1) of the strain rate sensitivity index value m is: （1）， wherein is the flow stress value, is the strain rate value; Then, the deformation energy dissipation rate value is calculated by using formula (2) and formula (3) and the unstable flow parameter value ζ: （2）， （3）； Step three, superimpose the energy dissipation rate contour map and the non-steady flow parameter distribution map, select the region where the energy dissipation rate value is 0.4~0.7, and the non-steady flow parameter value ζ is greater than 0, the region corresponding to the deformation temperature and strain rate is the high-temperature plastic deformation optimal process window of the obtained strong and tough titanium-based composite material sample. The titanium-based composite sample has a TiB particle, a TiB whisker or a TiC particle as a reinforcing phase, and a volume fraction of the reinforcing phase is 1-7 vol.%; The titanium alloy matrix of the titanium-based composite material is Ti6242, Ti55 or Ti65 alloy.

2. The method for strengthening and toughening a titanium-based composite material based on high-temperature plastic deformation according to claim 1, characterized in that, The diameter of the cylindrical titanium-based composite sample is 8-10 mm, and the height is 12-15 mm; The surface of the titanium-based composite sample is obtained by polishing, then placing in anhydrous ethanol, then ultrasonic vibration cleaning for 5-15 min, and then blowing dry.

3. The method for strengthening and toughening a titanium matrix composite through high-temperature plastic deformation according to claim 1, wherein Further comprising step four for detecting and verifying the toughening of the titanium-based composite material, specifically: Step A: under the optimal deformation temperature and strain rate conditions, the titanium-based composite sample is subjected to high temperature plastic deformation treatment; Step B: a plate-shaped tensile titanium-based composite sample is machined on the titanium-based composite sample subjected to high temperature plastic deformation, the gauge length is 10-15 mm, the width is 2-4 mm, and the thickness is 1-2 mm, and a room temperature tensile test is performed on an electronic universal testing machine.

4. The method of strengthening and toughening a titanium matrix composite by high-temperature plastic deformation according to claim 3, wherein In step A, the high temperature plastic deformation treatment of the titanium-based composite sample is free forging treatment, the titanium-based composite sample used is a cylindrical titanium-based composite sample cut from the titanium-based composite material, the surface of the cylindrical titanium-based composite sample is polished, then glass lubricant is applied, then the titanium-based composite sample is placed in a box furnace and heated to the optimal deformation temperature interval, and then kept for 10-30 min, and then placed in a hydraulic machine for high temperature plastic deformation treatment, and the deformation degree of the titanium-based composite sample reaches 30-50% within 30-50 s.

5. The method of strengthening and toughening a titanium matrix composite by high temperature plastic deformation according to claim 3, wherein The titanium-based composite sample used in step A is a cylindrical sample with a diameter of 20-50 mm and a height of 20-50 mm cut from the titanium-based composite material.

6. The method for strengthening and toughening a titanium matrix composite through high-temperature plastic deformation according to claim 1, wherein The titanium-based composite sample is a Ti55 composite material reinforced by 3-7 vol.% TiB whiskers; The high temperature plastic deformation treatment in step one is isothermal compression deformation treatment by a thermal simulation compression testing machine: after heating at 20 ℃ / s to 800 ℃ and then heating at 10 ℃ / s to a deformation temperature, the sample is kept for 5 min and then loaded, the deformation temperature is 920 ℃, 950 ℃, 980 ℃ and 1010 ℃, the strain rate is 0.001 s -1 , 0.01 s -1 , 0.1 s -1 and 1.0 s -1 ; and the deformation degree of the titanium-based composite sample is 50%.

7. The method for strengthening and toughening a titanium matrix composite through high-temperature plastic deformation according to claim 1, wherein The titanium-based composite sample is a Ti55 composite material reinforced by 3.5 vol.% TiB whiskers; The high temperature plastic deformation treatment described in step one is isothermal compression deformation treatment using a thermal simulation compression testing machine: after heating to 800℃ at 20℃ / s and then heating to the deformation temperature at 10℃ / s, the sample is loaded after 5 minutes of holding at the deformation temperature, the deformation temperature is 920℃, 950℃, 980℃ and 1010℃, the strain rate is 0.001s -1 , 0.01s -1 , 0.1s -1 and 1.0s -1 , and the deformation degree of the titanium-based composite sample is 30%.

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