阅读说明：本技术 一种TiB晶须增强钛基复合材料的制备方法 (Preparation method of TiB whisker reinforced titanium-based composite material ) 是由 胡正阳 彭海春 宋鹏 陈明 丁宇升 梁岳莹 于 2021-06-28 设计创作，主要内容包括：本发明提供了一种TiB晶须增强钛基复合材料的制备方法,其中该方法包括：将TiB-2粉和钛粉或钛合金粉加入球磨罐中,进行球磨处理后经干燥得到混合粉末；采用放电等离子系统对所述混合粉末进行烧结处理,得到复合材料块体；对所述复合材料块体进行双向垂直交替热轧处理,得到双向垂直交替热轧块体；将所述双向垂直热轧块体真空封装在石英管中,再放入热处理炉中进行热处理,得到所述TiB晶须增强钛基复合材料。本方案在不影响TiB相的结构完整性,并避免晶须异常粗化生长的前提下,通过双向垂直交替热轧和热处理对基体相组织进行优化调整,得到了高性能基体与晶须增强相高效协同强化的TiB增强钛基复合材料。(The invention provides a preparation method of a TiB whisker reinforced titanium-based composite material, wherein the method comprises the following steps: mixing TiB 2 Adding the powder and titanium powder or titanium alloy powder into a ball milling tank, carrying out ball milling treatment, and drying to obtain mixed powder; sintering the mixed powder by adopting a discharge plasma system to obtain a composite material block; performing bidirectional vertical alternate hot rolling treatment on the composite material block to obtain a bidirectional vertical alternate hot rolled block; and vacuum packaging the bidirectional vertical hot-rolled block in a quartz tube, and then putting the quartz tube into a heat treatment furnace for heat treatment to obtain the TiB whisker reinforced titanium-based composite material. The scheme does not influence the structural integrity of the TiB phase and avoids the abnormal coarsening growth of the crystal whiskerOn the premise of obtaining the TiB reinforced titanium-based composite material with high-performance matrix and whisker reinforced phase efficiently and synergistically strengthened by optimally adjusting the matrix phase structure through bidirectional vertical alternate hot rolling and heat treatment.)

1. A preparation method of a TiB whisker reinforced titanium matrix composite is characterized by comprising the following steps:

(1) mixing TiB₂Adding the powder and titanium powder or titanium alloy powder into a ball milling tank, carrying out ball milling treatment, and drying to obtain mixed powder;

(2) sintering the mixed powder by adopting a discharge plasma system to obtain a composite material block;

(3) performing bidirectional vertical alternate hot rolling treatment on the composite material block to obtain a bidirectional vertical alternate hot rolled block;

(4) and vacuum packaging the bidirectional vertical hot-rolled block in a quartz tube, and then putting the quartz tube into a heat treatment furnace for heat treatment to obtain the TiB whisker reinforced titanium-based composite material.

2. The method of claim 1, wherein:

in the step (1), the first step of the method,

the TiB₂The mass ratio of the powder to the titanium powder or the titanium alloy powder is (0.1-25) to (99.9-75);

the particle size of the titanium powder or the titanium alloy powder is less than or equal to 100 mu m;

the TiB₂The particle size of the powder is less than or equal to 3 mu m.

3. The method of claim 1, wherein:

in the step (1), the ball milling medium in the ball milling treatment is absolute ethyl alcohol or acetone;

the ball-material ratio in the ball milling treatment is 1-10: 1;

the rotating speed in the ball milling treatment is 150r/min-550 r/min;

the ball milling time of the ball milling treatment is 0.5h-5 h.

4. The production method according to claim 3, characterized in that:

the grinding balls in the ball milling treatment consist of first agate balls and second agate balls, wherein the diameter of the first agate balls is larger than that of the second agate balls;

the mass ratio of the first agate balls to the second agate balls in the grinding balls is 0.1-10: 1;

the diameter of the second agate ball is 1mm-5 mm;

the diameter ratio of the first agate balls to the second agate balls is 2-8: 1.

5. The method of claim 1, wherein:

in the step (1), the drying includes:

the TiB after ball milling treatment is treated₂The powder and titanium powder or titanium alloy powder are dried for 0.2 to 2 hours at the temperature of between 70 and 80 ℃ in vacuum by rotary evaporation, and then dried for 0.2 to 2 hours at the temperature of between 30 and 60 ℃.

6. The method of claim 5, wherein:

the vacuum drying adopts a vacuum rotary evaporator, and the rotating speed of the vacuum rotary evaporator is 30r/min-120 r/min.

7. The method of claim 1, wherein:

in the step (2), the sintering process includes:

heating at a heating rate of 50-200 ℃/min under the conditions that the initial vacuum degree is less than 15Pa and the initial pressure is 0.1-5 MPa; when the temperature is raised to 650-850 ℃ and the vacuum degree is less than 15Pa, adjusting the heating rate to 20-50 ℃/min, simultaneously pressurizing, timing when the temperature is raised to 700-900 ℃, the pressure reaches 3-80 MPa and the displacement rate variation of the sintered mixed powder is less than or equal to 0.05mm/min, and preserving heat and pressure for 3-30 min; and then closing the heating system, simultaneously unloading pressure at the speed of 0.1kN/s-5kN/s, and cooling to below 250 ℃ along with the furnace to obtain the composite material block.

8. The method of claim 1, wherein:

in the step (3), the bidirectional vertical alternating hot rolling process includes:

polishing the composite material block to remove an oxide film on the surface of the composite material block to obtain a blank;

heating the blank at 950-1250 ℃ for 3-25 min, then carrying out hot rolling by adopting a rolling mill with a flat roller, and carrying out at least three-pass treatment, wherein the temperature of the rolling mill is room temperature, the final rolling temperature of the hot rolling is 780-1080 ℃, the single-pass deformation is 4-10%, the rolling direction of each pass is vertical to that of the previous pass, and the total deformation is 28-70%; the heating temperature of the furnace returning between each pass is 800-1100 ℃, and the heating time is 1-10 min; after finishing rolling, returning to the furnace and heating again, wherein the heating temperature is 950-1050 ℃, and the heating time is 3-8 min; and water quenching treatment is carried out after heating to obtain the bidirectional vertical alternating hot rolled block.

9. The method of claim 8, wherein:

and in the water quenching treatment, a water quenching medium is a NaCl solution with the mass fraction of 5-15%.

10. The production method according to any one of claims 1 to 9, characterized in that:

in the step (4), the heat treatment includes:

the heat treatment temperature of the heat treatment is 450-750 ℃;

the heat treatment time of the heat treatment is 10min-240 min.

Technical Field

The embodiment of the invention relates to the technical field of metal matrix composite materials, in particular to a preparation method of a TiB whisker reinforced titanium matrix composite material.

Background

Titanium-based composite materials (TMCs) are compounded by using pure titanium or titanium alloy as a matrix and ceramic reinforcing phases (particles, whiskers and continuous fibers) as reinforcing bodies. The titanium-based composite material has high specific strength and specific stiffness, good wear resistance, high temperature resistance, low thermal expansion coefficient, non-magnetism, difficult aging and other excellent performances, and is widely applied to the fields of aerospace, automobile industry, biomedical treatment and the like.

The TiB whisker is one of whisker reinforcements commonly used for titanium-based composite materials, and can simultaneously meet the following conditions: (1) the strength, rigidity, heat resistance and other physical and mechanical properties are excellent; (2) is thermodynamically stable in the matrix; (3) the difference between the linear expansion coefficient of the material and the linear expansion coefficient of the substrate is small, and the interface bonding is stable; (4) the elements contained in the reinforcing phase are not dissolved in the matrix at high temperature. Thus, in recent years, TiB whisker reinforced titanium matrix composites have been extensively studied.

At present, solid phase high-temperature sintering is one of the most common preparation methods for TiB whisker reinforced titanium-based composite materials, but because a matrix phase in the TiB whisker reinforced titanium-based composite material is a main component, the organization structure of the TiB whisker reinforced titanium-based composite material is the basis for determining the final performance of the composite material, and the matrix in the composite material prepared by the method is in a sintering state and is easy to generate defects of closed pores, overburning, underburning and the like, so that the matrix organization needs to be adjusted through subsequent hot working and heat treatment to meet the required mechanical performance. However, when the matrix structure of the TiB whisker reinforced titanium matrix composite is optimally adjusted by the existing hot working and heat treatment modes, the structural integrity of the TiB phase is affected, and the whisker grows abnormally and coarsens, so that the TiB whisker reinforced titanium matrix composite with high performance matrix and whisker reinforcement and high efficiency synergistic reinforcement cannot be obtained.

Disclosure of Invention

The embodiment of the invention provides a preparation method of a TiB whisker reinforced titanium-based composite material, which can provide a TiB reinforced titanium-based composite material with a high-performance matrix and whisker reinforced phase efficiently and synergistically.

The invention provides a preparation method of a TiB whisker reinforced titanium-based composite material, which comprises the following steps:

(1) mixing TiB₂Adding the powder and titanium powder or titanium alloy powder into a ball milling tank, carrying out ball milling treatment, and drying to obtain mixed powder;

(2) sintering the mixed powder by adopting a discharge plasma system to obtain a composite material block;

(3) performing bidirectional vertical alternate hot rolling treatment on the composite material block to obtain a bidirectional vertical alternate hot rolled block;

(4) and vacuum packaging the bidirectional vertical hot-rolled block in a quartz tube, and then putting the quartz tube into a heat treatment furnace for heat treatment to obtain the TiB whisker reinforced titanium-based composite material.

Preferably, in step (1),

the TiB₂The mass ratio of the powder to the titanium powder or the titanium alloy powder is (0.1-25) to (99.9-75);

the particle size of the titanium powder or the titanium alloy powder is less than or equal to 100 mu m;

the TiB₂The particle size of the powder is less than or equal to 3 mu m.

Preferably, in the step (1), the ball milling medium in the ball milling treatment is absolute ethyl alcohol or acetone;

the ball-material ratio in the ball milling treatment is 1-10: 1;

the rotating speed in the ball milling treatment is 150r/min-550 r/min;

the ball milling time of the ball milling treatment is 0.5h-5 h.

Preferably, the grinding balls in the ball milling treatment consist of first agate balls and second agate balls, wherein the diameter of the first agate balls is larger than that of the second agate balls;

the mass ratio of the first agate balls to the second agate balls in the grinding balls is 0.1-10: 1;

the diameter of the second agate ball is 1mm-5 mm;

the diameter ratio of the first agate balls to the second agate balls is 2-8: 1.

Preferably, in step (1), the drying comprises:

the TiB after ball milling treatment is treated₂The powder and titanium powder or titanium alloy powder are dried for 0.2 to 2 hours at the temperature of between 70 and 80 ℃ in vacuum by rotary evaporation, and then dried for 0.2 to 2 hours at the temperature of between 30 and 60 ℃;

preferably, the vacuum drying adopts a vacuum rotary evaporator, and the rotating speed of the vacuum rotary evaporator is 30r/min-120 r/min.

Preferably, in the step (2), the sintering process includes:

heating at a heating rate of 50-200 ℃/min under the conditions that the initial vacuum degree is less than 15Pa and the initial pressure is 0.1-5 MPa; when the temperature is raised to 650-850 ℃ and the vacuum degree is less than 15Pa, adjusting the heating rate to 20-50 ℃/min, simultaneously pressurizing, timing when the temperature is raised to 700-900 ℃, the pressure reaches 3-80 MPa and the displacement rate variation of the sintered mixed powder is less than or equal to 0.05mm/min, and preserving heat and pressure for 3-30 min; and then closing the heating system, simultaneously unloading pressure at the speed of 0.1kN/s-5kN/s, and cooling to below 250 ℃ along with the furnace to obtain the composite material block.

Preferably, in the step (3), the bidirectional vertical alternating hot rolling process includes:

polishing the composite material block to remove an oxide film on the surface of the composite material block to obtain a blank;

heating the blank at 950-1250 ℃ for 3-25 min, then carrying out hot rolling by adopting a rolling mill with a flat roller, and carrying out at least three-pass treatment, wherein the temperature of the rolling mill is room temperature, the final rolling temperature of the hot rolling is 780-1080 ℃, the single-pass deformation is 4-10%, the rolling direction of each pass is vertical to that of the previous pass, and the total deformation is 28-70%; the heating temperature of the furnace returning between each pass is 800-1100 ℃, and the heating time is 1-10 min; after finishing rolling, returning to the furnace and heating again, wherein the heating temperature is 950-1050 ℃, and the heating time is 3-8 min; and water quenching treatment is carried out after heating to obtain the bidirectional vertical alternating hot rolled block.

Preferably, the water quenching medium in the water quenching treatment is a NaCl solution with the mass fraction of 5% -15%.

Preferably, in step (4), the heat treatment includes:

the heat treatment temperature of the heat treatment is 450-750 ℃;

the heat treatment time of the heat treatment is 10min-240 min.

Compared with the prior art, the invention at least has the following beneficial effects:

(1) the invention combines ball milling, spark plasma sintering, bidirectional vertical alternate hot rolling and heat treatment, and can optimize and adjust the matrix phase structure of the composite material on the premise of not influencing the structural integrity of the TiB phase and avoiding the abnormal coarsening growth of the whisker. Wherein, by ball milling process, TiB can be prepared₂The powder is mixed with titanium powder or titanium alloy powder. By utilizing the characteristics of continuous resistance heat and instantaneous high-temperature plasma dual heating mechanism of a discharge plasma system and the advantages of controllable external pressure and sintering atmosphere, TiB is controlled at lower sintering temperature and medium and low external pressure₂On the premise that the particles and the surrounding titanium or titanium alloy matrix have in-situ reaction to a limited extent, the densification, sintering and molding of the composite material block are realized. For common titanium and titanium alloy matrixes, the density of a composite material block prepared by sintering through a point-placing plasma system can reach more than 96%. By bidirectional vertical alternate hot rolling treatment, on one hand, the reaction temperature and time can be controlled, and the normal growth of the crystal whisker is promoted. On the other hand, the defects in the matrix structure can be reduced, and the density is improved. Through quenching and aging heat treatment, the thermal stress caused in sintering and hot rolling treatment can be partially eliminated, and meanwhile, aging strengthening treatment is carried out on the matrix structure, so that the toughness of the composite material is further improved. Therefore, the preparation method solves the problems of whisker fracture and coarsening and matrix grain growth in the hot working process of the sintered TiB whisker reinforced titanium-based composite material.

(2) The TiB whisker reinforced titanium-based composite material based on matrix tissue regulation and control is prepared, wherein the TiB whisker has a complete structure and a high length-diameter ratio, and has good interface bonding with a matrix; and the matrix structure is compact, the residual thermal stress degree is low, the sintering defect is fully eliminated, and the thermal deformation and the heat treatment introduce additional dislocation strengthening, dispersion strengthening and other mechanisms, so that the strength of the material is further improved.

(3) The preparation method of the TiB whisker reinforced titanium-based composite material provided by the invention is simple and feasible, short in preparation period and strong in practicability, and is beneficial to industrialization.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a flow chart of a method for preparing a TiB whisker reinforced titanium matrix composite according to an embodiment of the invention;

fig. 2 is an SEM image of a composite material block provided in accordance with an embodiment 1 of the present invention;

FIG. 3 is an SEM image of a TiB whisker reinforced titanium matrix composite material provided in embodiment 1 of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention, and based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the scope of the present invention.

As mentioned above, when the matrix structure of the TiB whisker reinforced titanium matrix composite is optimally adjusted by the existing hot working and heat treatment methods, the structural integrity of the TiB phase is affected, resulting in abnormal coarsening growth of the whiskers. In particular, the amount of the solvent to be used,

(1) TiB is a ceramic phase with high hardness and certain brittleness, and is easy to break and damage during thermal deformation, so that the length-diameter ratio is reduced, and the load transfer strengthening effect of a reinforcing phase is damaged. The addition of TiB in the titanium matrix can cause the increase of the rheological stress of the composite material and the reduction of the plasticity;

(2) the thermal deformation and the solution treatment temperature of the alpha + beta double-phase region of the titanium-based composite material are partially overlapped with the growth temperature range of the TiB phase, so that the problems of crystal whisker coarsening and the like exist in the hot working and heat treatment processes;

(3) although the TiB reinforcement belongs to a stable phase in the heat treatment process at the temperature of the heat deformation of the alpha single-phase region of the titanium-based composite material and the heat treatment such as annealing, aging and the like, the reinforcement can also influence the processes of phase transformation, nucleation of precipitated phases, growth of grains and the like of the matrix alloy in the heat treatment process.

Therefore, a preparation method of the TiB whisker reinforced titanium-based composite material is needed, which is used for optimizing and adjusting a matrix of the titanium-based composite material in a thermal deformation and thermal treatment mode on the premise of not influencing the structural integrity of a TiB phase and avoiding the abnormal coarsening and growth of whiskers to obtain the TiB reinforced titanium-based composite material with a high-performance matrix and efficient synergistic reinforcement of whisker reinforcement.

As shown in fig. 1, a method for preparing a TiB whisker reinforced titanium matrix composite according to an embodiment of the present invention includes the following steps:

step (1) of mixing TiB₂Adding the powder and titanium powder or titanium alloy powder into a ball milling tank, carrying out ball milling treatment, and drying to obtain mixed powder;

step (2), sintering the mixed powder by adopting a discharge plasma system to obtain a composite material block;

step (3), performing bidirectional vertical alternate hot rolling treatment on the composite material block to obtain a bidirectional vertical alternate hot rolled block;

and (4) vacuum packaging the bidirectional vertical hot-rolled block in a quartz tube, and then putting the quartz tube into a heat treatment furnace for heat treatment to obtain the TiB whisker reinforced titanium-based composite material.

According to the invention, through the combination of ball milling, spark plasma sintering, bidirectional vertical alternate hot rolling and heat treatment, the structure integrity of the TiB phase is not influenced, and the matrix phase structure of the composite material is optimally adjusted on the premise of avoiding abnormal coarsening growth of whiskers, so that the TiB whiskers in the composite material have complete structure and high length-diameter ratio, and have good interface combination with the matrix; and the matrix structure is compact, the residual thermal stress degree is low, and the sintering defect is fully eliminated, so that the strength level of the material is further improved, and the TiB whisker reinforced titanium-based composite material with high performance matrix and whisker reinforced high-efficiency synergistic reinforcement is obtained.

According to some preferred embodiments, in step (1),

the TiB₂The mass ratio of the powder to the titanium powder or the titanium alloy powder is (0.1-25) to (99.9-75);

the particle size of the titanium powder or the titanium alloy powder is less than or equal to 100 mu m;

the TiB₂The particle size of the powder is less than or equal to 3 mu m.

Note that TiB₂The mass ratio of the powder to the titanium powder is (0.1-25) to (99.9-75); TiB₂The mass ratio of the powder to the titanium alloy powder is (0.1-25) to (99.9-75). The grain diameter of the titanium powder is less than or equal to 100 mu m; the grain diameter of the titanium alloy powder is less than or equal to 100 mu m.

The experiment proves that TiB₂The mass ratio of the powder to the titanium powder or titanium alloy powder is (0.1-25): 99.9-75) (for example, 0.1:99.9, 0.5:99.5, 1:99, 5:95, 10:90, 15:85, 20:80 or 25: 75); the particle size of the titanium powder or titanium alloy powder is less than or equal to 100 μm (for example, 0.04 μm, 5 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm); TiB₂The particle size of the powder is not more than 3 μm (for example, it may be 0.05. mu.m, 0.08. mu.m, 0.1. mu.m, 1. mu.m, 1.5. mu.m, 2. mu.m, 2.5. mu.m, or 3 μm).

The particle diameters are all average particle diameters.

According to some preferred embodiments, in step (1),

the ball milling medium in the ball milling treatment is absolute ethyl alcohol or acetone;

the ball-material ratio in the ball milling treatment is 1-10: 1;

the rotating speed in the ball milling treatment is 150r/min-550 r/min;

the ball milling time of the ball milling treatment is 0.5h-5 h.

Preferably, the ball milling treatment adopts an SM-QB planetary ball mill.

Experiments prove that the ball-to-material ratio in the ball milling treatment is 1-10:1 (for example, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10: 1); the rotating speed is 150r/min-550r/min (for example, 150r/min, 200r/min, 300r/min, 350r/min, 400r/min, 450r/min, 500r/min or 550 r/min); the ball milling time is 0.5h-5h (for example, 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5 h).

According to some preferred embodiments, in step (1),

the grinding balls in the ball milling treatment consist of first agate balls and second agate balls, wherein the diameter of the first agate balls is larger than that of the second agate balls;

the mass ratio of the first agate balls to the second agate balls in the grinding balls is 0.1-10: 1;

the diameter of the second agate ball is 1mm-5 mm;

the diameter ratio of the first agate balls to the second agate balls is 2-8: 1.

The first agate ball is a big agate ball, and the second agate ball is a small agate ball.

Experiments prove that the mass ratio of the large agate balls to the small agate balls in the grinding balls is 0.1-10:1 (for example, the mass ratio can be 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10: 1); the small agate balls have a diameter of 1mm to 5mm (e.g., may be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5 mm); the ratio of the diameter of the large agate ball to the small agate ball is 2-8:1 (e.g., 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, or 8: 1).

According to some preferred embodiments, in step (1), the drying comprises:

the TiB after ball milling treatment is treated₂The powder and titanium powder or titanium alloy powder are dried for 0.2 to 2 hours at the temperature of between 70 and 80 ℃ in vacuum by rotary evaporation, and then dried for 0.2 to 2 hours at the temperature of between 30 and 60 ℃;

according to some more preferred embodiments, the vacuum drying is performed by using a vacuum rotary evaporator, and the rotating speed of the vacuum rotary evaporator is 30r/min-120 r/min.

Specifically, TiB₂Adding powder, titanium powder or titanium alloy powder and ball-milling medium into a ball-milling tank, mixing to obtain mixed slurry, pouring the mixed slurry into a rotary evaporator, rotary evaporating at 70-80 deg.C (70 deg.C, 72 deg.C, 74 deg.C, 76 deg.C, 78 deg.C or 80 deg.C) at 30-120 r/min (30 r/min, 40r/min, 50r/min, 60r/min, 70r/min, 80r/min, 90r/min, 100r/min, 110r/min or 120r/min) for 0.2-2 h (0.2 h, 0.4h, 0.6h, 0.8h, 1h, 1.5h or 2h), volatilizing the ball-milling medium, and vacuum drying at 30-60 deg.C (30 deg.C, 35 deg.C, 40 deg.C), Drying at 45 deg.C, 50 deg.C, 55 deg.C or 60 deg.C for 0.2-2 hr to obtain mixed powder.

The drying equipment after vacuum drying is not particularly limited, and can be a constant-temperature air-blast drying oven.

In the present invention, TiB can be prepared by a ball milling process₂The powder is mixed with titanium powder or titanium alloy powder uniformly, and at the same time, TiB₂The surface of the titanium or titanium alloy powder particles will be embedded during the mixing process.

According to some preferred embodiments, in the step (2), the sintering process includes:

heating at a heating rate of 50-200 ℃/min under the conditions that the initial vacuum degree is less than 15Pa and the initial pressure is 0.1-5 MPa; when the temperature is raised to 650-850 ℃ and the vacuum degree is less than 15Pa, adjusting the heating rate to 20-50 ℃/min, simultaneously pressurizing, timing when the temperature is raised to 700-900 ℃, the pressure reaches 3-80 MPa and the displacement rate variation of the sintered mixed powder is less than or equal to 0.05mm/min, and preserving heat and pressure for 3-30 min; and then closing the heating system, simultaneously unloading pressure at the speed of 0.1kN/s-5kN/s, and cooling to below 250 ℃ along with the furnace to obtain the composite material block.

In a preferred embodiment, the temperature is raised at a temperature raising rate of 50 ℃/min to 200 ℃/min (for example, 50 ℃/min, 80 ℃/min, 100 ℃/min, 120 ℃/min, 150 ℃/min, 180 ℃/min, or 200 ℃/min) at an initial vacuum degree of <15Pa (for example, 2Pa, 5Pa, 8Pa, 10Pa, 12Pa, or 14Pa), an initial pressure of 0.1MPa to 5MPa (for example, 0.1MPa, 0.2MPa, 0.5MPa, 1MPa, 1.5MPa, 2MPa, 2.5MPa, 3MPa, 3.5MPa, 4MPa, 4.5MPa, or 5 MPa); when the temperature is raised to 650-850 ℃ (for example, 650 ℃, 700 ℃, 750 ℃, 800 ℃ or 850 ℃) and the degree of vacuum is less than 15Pa, the temperature raising rate is adjusted to 20-50 ℃/min (for example, 20-, 30-, 40-or 50 ℃/min), while pressurizing, the temperature is raised to 700-900 ℃ (for example, 700-, 750-, 800 ℃, 850 ℃ or 900 ℃), the pressure is raised to 3-80 MPa (for example, 3-, 10-, 20-, 30-, 40-, 50-, 60-, 70-, or 80MPa), and the variation of the displacement rate of the sintered mixed powder is less than or equal to 0.05mm/min (for example, 0.01-, 0.02-, 0.03-, 0.04-, or 0.05mm/min), the pressure is maintained for 3-30 min (for example, can be 3min, 5min, 10min, 15min, 20min, 25min or 30 min); the heating system is then turned off while the pressure is removed at a rate of 0.1kN/s to 5kN/s (e.g., can be 0.1kN/s, 0.2kN/s, 0.3kN/s, 0.4kN/s, or 5kN/s) and furnace cooled to below 250 ℃ (e.g., can be 50 ℃, 80 ℃, 100 ℃, 150 ℃, 180 ℃, 200 ℃, or 240 ℃) to provide a composite block. And after the composite material block is cooled to 60 ℃ in the air, sequentially washing the surface of the composite material block by using deionized water and ethanol, and drying.

In the invention, the TiB is controlled at a lower sintering temperature and a medium-low external pressure by utilizing the characteristics of a continuous resistance heat and instantaneous high-temperature plasma dual heating mechanism of a discharge plasma system and the advantages of controllable external pressure and sintering atmosphere₂On the premise that the particles and the surrounding titanium or titanium alloy matrix have in-situ reaction to a limited extent, the densification of the composite material block is realizedAnd (5) sintering and forming.

According to some preferred embodiments, in step (3),

the bidirectional vertical alternating hot rolling treatment comprises the following steps:

polishing the composite material block to remove an oxide film on the surface of the composite material block to obtain a blank;

heating the blank at 950-1250 ℃ for 3-25 min, then carrying out hot rolling by adopting a rolling mill with a flat roller, and carrying out at least three-pass treatment, wherein the temperature of the rolling mill is room temperature, the final rolling temperature of the hot rolling is 780-1080 ℃, the single-pass deformation is 4-10%, the rolling direction of each pass is vertical to that of the previous pass, and the total deformation is 28-70%; the heating temperature of the furnace returning between each pass is 800-1100 ℃, and the heating time is 1-10 min; after finishing rolling, returning to the furnace and heating again, wherein the heating temperature is 950-1050 ℃, and the heating time is 3-8 min; and water quenching treatment is carried out after heating to obtain the bidirectional vertical alternating hot rolled block.

Specifically, each surface of the composite material block is polished by using sand paper to remove the surface oxide film to obtain a blank, so that edge cracking caused by the existence of the surface oxide film in the rolling process is avoided.

In a preferred embodiment, the billet is heated at 950 ℃ to 1250 ℃ (e.g., 950 ℃, 980 ℃, 1000 ℃, 1050 ℃, 1080 ℃, 1200 ℃ or 1250 ℃) for 3min to 25min (e.g., 3min, 5min, 10min, 15min, 20min or 25min), then hot rolled using a rolling mill with flat rolls, at least three passes (e.g., three, four, five, six, seven, eight, nine or ten passes, etc.) of rolling at room temperature (e.g., 780 ℃ to 1080 ℃ (780 ℃, 800 ℃, 850 ℃, 900 ℃, 1000 ℃, 1050 ℃, or 1080 ℃), and a single pass deformation of 4% to 10% (e.g., 4%, 5%, 6%, 7%, 8%, 9%, or 10%), the rolling direction of each pass is perpendicular to the rolling direction of the previous pass, and the total deformation is 28-70% (for example, 28%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% or 70% can be achieved); the heating temperature of each inter-pass annealing is 800-1100 deg.C (for example, 800 deg.C, 850 deg.C, 900 deg.C, 950 deg.C, 1000 deg.C, 1050 deg.C or 1100 deg.C), and the heating time is 1-10 min (for example, 1min, 3min, 5min, 7min, 9min or 10 min); returning to the furnace and heating again after finishing rolling, wherein the heating temperature is 950 ℃ -1050 ℃ (for example, 950 ℃, 980 ℃, 1000 ℃, 1020 ℃ or 1050 ℃), and the heating time is 3min-8min (for example, 3min, 4min, 5min, 6min, 7min or 8 min); and water quenching treatment is carried out after heating to obtain the bidirectional vertical alternating hot rolled block.

On the premise of ensuring the performance of the composite material, when the hot rolling is carried out in order to have a shorter preparation period, at least three passes of treatment are preferably carried out, and the three passes, the four passes, the five passes, the six passes or the seven passes can be preferably carried out.

The rolling direction of each pass is perpendicular to the rolling direction of the previous pass. For example, when a rectangular block is rolled for the first pass, the long side of the rectangular block is fed into a flat roll mill for hot rolling (i.e., the long side of the rectangular block is perpendicular to the direction of movement of the block, so that the short side of the rectangular block is stretched); when the second pass rolling is carried out, the rolling direction is changed, the short side of the original cuboid is sent into a rolling mill with flat rolls for hot rolling (namely, the short side of the cuboid is vertical to the movement direction of the billet, so that the direction of the extending side of the cuboid can be stretched), and the rolling is carried out alternately.

According to the invention, through bidirectional vertical alternate hot rolling treatment, the reaction temperature and time can be controlled, the normal growth of whiskers is promoted, the defects in the matrix tissue can be reduced, and the density is improved; and a dislocation strengthening mechanism is introduced through thermal deformation, so that the strength of the composite material is further improved. Meanwhile, by limiting the single-pass deformation and adopting a vertical alternating hot rolling process, the anisotropy can be avoided and the isotropy of the composite material is ensured.

According to some preferred embodiments, the water quenching medium in the water quenching treatment is a NaCl solution with a mass fraction of 5% to 15%.

In a preferred embodiment, the water quenching medium in the water quenching process may be a 5%, 6%, 8%, 10%, 12% or 15% NaCl solution.

In the invention, the water quenching medium is not limited to NaCl solution with the mass fraction of 5-15%, and deionized water can be used for water quenching treatment, but preferably, NaCl solution with the mass fraction of 5-15% is used, so that the titanium-based composite material after rolling has good hardenability, and the effectiveness of the quenching process is ensured.

According to some preferred embodiments, in step (4), the heat treatment comprises:

the heat treatment temperature of the heat treatment is 450-750 ℃;

the heat treatment time of the heat treatment is 10min-240 min.

In a preferred embodiment, the bidirectional vertical alternating hot rolling block is put into a heat treatment furnace, the heat treatment temperature is 450 ℃ -750 ℃ (for example, 450 ℃, 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃ or 750 ℃), the heat treatment time is 10min-240min (for example, 10min, 20min, 50min, 80min, 100min, 150min, 200min or 240min), and after the heat treatment is finished, the TiB whisker reinforced titanium matrix composite is obtained after cooling (preferably, cooling to below 200 ℃ along with the heat treatment furnace), cleaning and drying.

In the invention, through quenching and heat treatment, the thermal stress caused in the sintering and hot rolling treatment can be partially eliminated, and meanwhile, the aging strengthening treatment is carried out on the matrix structure, thereby further improving the toughness of the composite material.

The invention also provides a TiB whisker reinforced titanium-based composite material which is prepared by the preparation method of the TiB whisker reinforced titanium-based composite material.

The TiB whisker reinforced titanium-based composite material prepared by the preparation method of the TiB whisker reinforced titanium-based composite material provided by the invention has compact matrix structure, low residual thermal stress degree and obviously improved strength; and the TiB whisker has a complete structure and high length-diameter ratio, and has good interface bonding with a matrix.

In order to more clearly illustrate the technical scheme and the advantages of the invention, the following describes a preparation method of the TiB whisker reinforced titanium matrix composite material in detail through several embodiments.

In the following examples:

TC4 powder (titanium alloy powder) is purchased from Beijing Haoyuan industrial and trade company, the particle shape is nearly circular, the average particle diameter is 30 μm, the purity is more than or equal to 99.9 wt%, and the components and the mass fraction (wt%) are shown in Table 1:

TABLE 1

The Ti powder (titanium powder) is purchased from a Beijing Taixin Longman metal material processing factory, is in an irregular polygon shape, has the average grain diameter of about 40 mu m and has the purity of more than 99.0wt percent;

TiB₂the powder is purchased from Ningxia mechanical research institute, the purity is more than or equal to 99.5 wt%, the average particle size is 80nm, and the main impurity elements are as follows: o is<0.4wt％，C<0.15wt％；

The absolute ethyl alcohol and the acetone are from Guang fine chemical company of Beijing;

the spark plasma sintering system was SPS-3.20-MV from Nippon sumitomo Stone coal mining Co., Ltd;

the rolling mill is a 350 reversible multifunctional rolling mill;

the room temperature static stretching is carried out on an in-situ stretching device (CS3400 type), each sample is tested for five times, and the average value is taken as the actual performance of the sample; the actual performance comprises the following performance parameters: tensile strength, yield strength and elongation;

microscopic structure observation is carried out by adopting a field emission scanning electron microscope (SEM, Hitachi S-4800N, Hitachi, Japan) to observe the structure appearance of the sample surface after polishing and corrosion;

the length-diameter ratio and the diameter of the TiB crystal whisker are obtained by analyzing and processing SEM pictures through Image-Pro Plus 6.0 software (MEDIA CYBERNEETICS Image technology company, USA);

the actual density is determined according to the method specified in the national standard GB/T1423 + 1996 test method for the density of the noble metal and the alloy thereof;

the calculation formula of the density D is as follows: d ═ p (p)_{Practice of}/ρ_{Theory of the invention}) X 100%, where ρ_{Practice of}Representing the actual density, p_{Theory of the invention}Representing the theoretical density.

Example 1

(1) 0.09gTiB₂Adding the powder and 19.91g of TC4 powder into a ball milling tank of an SM-QB planetary ball mill, adding grinding balls and absolute ethyl alcohol according to a ball-to-material ratio of 4:1, carrying out ball milling treatment for 1h at the rotating speed of 300r/min to obtain uniformly mixed slurry, pouring the mixed slurry into a vacuum rotary evaporator, carrying out rotary evaporation for 0.5h at the temperature of 70 ℃ at 80r/min, and drying for 1.5h in an electric heating constant-temperature gulf drying cabinet at the temperature of 40 ℃ after acetone is volatilized completely to obtain mixed powder;

the grinding balls consist of large agate balls and small agate balls in a mass ratio of 2:1, the diameter ratio of the large agate balls to the small agate balls is 3:1, and the diameter of the small agate balls is 5 mm;

(2) putting 20g of the mixed powder obtained in the step (1) into a cylindrical graphite die with the inner diameter of 25mm, wherein the mixed powder is separated from the side wall of the die and a pressure head by 0.1mm of graphite foil, then putting the die into an SPS-3.20-MV discharge plasma system, setting the initial vacuum degree in a cranial cavity to be 2Pa, setting the initial pressure to be 0.2MPa, and heating at the heating rate of 80 ℃/min; when the temperature is increased to 800 ℃ and the vacuum degree is 5Pa, adjusting the heating rate to 30 ℃/min, simultaneously pressurizing, timing when the temperature is increased to 850 ℃, the pressure reaches 50MPa and the displacement rate variation of the sintered mixed powder is 0.02mm/min, and keeping the temperature and the pressure for 10 min; and then closing the heating system, simultaneously unloading the pressure at the speed of 1kN/s, and cooling to 200 ℃ along with the furnace to obtain the composite material block. After the composite material block is cooled to 60 ℃ in the air, firstly cleaning the surface of the composite material block by using deionized water, then cleaning the surface of the composite material block by using ethanol (so as to remove graphite foil), and drying;

(3) sequentially polishing each surface of the composite material block cleaned and dried in the step (2) by using 80-mesh, 200-mesh, 600-mesh, 1000-mesh, 1500-mesh and 2000-mesh sandpaper to remove an oxide film on the surface of the composite material block to obtain a blank; heating the blank at 1050 ℃ for 6min, then carrying out hot rolling by adopting a rolling mill with a flat roller as a roller, and carrying out seven-pass treatment, wherein the temperature of the roller is room temperature, the final temperature of the hot rolling is 930 ℃, the single-pass deformation is 10%, the rolling direction of each pass is vertical to that of the previous pass, and the total deformation is 70%; the heating temperature of each inter-pass remelting is 950 ℃, and the heating time is 1.5 min; returning to the furnace and heating again after finishing rolling, wherein the heating temperature is 1000 ℃, and the heating time is 5 min; after heating, carrying out water quenching treatment by adopting a NaCl solution with the mass fraction of 15%, and cleaning and drying to obtain the bidirectional vertical alternating hot rolled block;

(4) and (3) vacuum packaging the bidirectional vertical hot-rolled block obtained in the step (3) in a quartz tube, then placing the quartz tube into an OTF-1200X-S heat treatment furnace at 660 ℃ for heat treatment for 60min, then cooling the quartz tube to 80 ℃ along with the heat treatment furnace, taking out, cleaning and drying the cooled product, and obtaining the TiB whisker reinforced titanium-based composite material.

The room temperature was 25 ℃.

The TiB whisker reinforced titanium-based composite material obtained in the example was prepared into a sample and tested, and the test results (see Table 2) were as follows:

a) the density of the TiB whisker reinforced titanium-based composite material is 99.7 percent;

b) the mechanical property of the TiB whisker reinforced titanium-based composite material is as follows: isotropy, wherein the tensile strength is 1370MPa, the tensile yield strength is 1344MPa, and the tensile elongation is 5.1 percent;

c) the analysis result of the SEM image (see fig. 2) of the composite material block prepared by spark plasma sintering in step (3) is as follows:

when the sintering temperature of 850 ℃ is used, the sintering neck connection and the formation of grain boundaries between matrix particles are already completed, and the densification is already performed preliminarily. TC4 and TiB₂Has a limited degree of in situ reaction between, unreacted TiB₂The phase and the TiB primary phase generated by the reaction are mixed and distributed at the position of the matrix grain boundary. As can be seen from FIG. 2, unreacted TiB₂The phase is in an initial granular shape, and the TiB primary phase generated by the reaction is in a short whisker shape; at the analyzed positionThe average length of the TiB primary phase in the form of short whiskers is 0.9 mu m, and the average length-diameter ratio is 23;

e) the analysis result of the SEM image (see figure 3) of the TiB whisker reinforced titanium matrix composite material is as follows:

in the TiB whisker reinforced titanium-based composite material, the TiB whisker reinforced titanium-based composite material is obtained by analysis treatment, wherein the average length-diameter ratio of the TiB whisker is 57, and the average diameter of the whisker is 70 nm; as can be seen from fig. 3, the TiB nanowhiskers of the reinforcing phase are uniformly distributed in the composite material in a three-dimensional network, have good integrity, have no whiskers coarsening abnormally, have a clean interface with the matrix, are firmly bonded, have no preferred orientation in the tissue, and can effectively exert the load transfer effect.

Example 2

(1) 0.02gTiB₂Adding the powder and 19.98g of TC4 powder into a ball milling tank of an SM-QB planetary ball mill, adding grinding balls and absolute ethyl alcohol according to a ball-to-material ratio of 1:1, carrying out ball milling treatment for 0.5h at the rotating speed of 550r/min to obtain uniformly mixed slurry, pouring the mixed slurry into a vacuum rotary evaporator, carrying out rotary evaporation for 0.2h at the temperature of 80 ℃ at 120r/min, and drying for 2h in an electric heating constant-temperature gulf drying cabinet at the temperature of 30 ℃ after acetone is volatilized completely to obtain mixed powder;

the grinding ball consists of a large agate ball and a small agate ball in a mass ratio of 0.1:1, the diameter ratio of the large agate ball to the small agate ball is 8:1, and the diameter of the small agate ball is 1 mm;

(2) putting 20g of the mixed powder obtained in the step (1) into a cylindrical graphite die with the inner diameter of 25mm, wherein the mixed powder is separated from the side wall of the die and a pressure head by 0.1mm of graphite foil, then putting the die into an SPS-3.20-MV discharge plasma system, setting the initial vacuum degree in a cranial cavity to be 2Pa, setting the initial pressure to be 5MPa, and heating at the heating rate of 50 ℃/min; when the temperature is raised to 650 ℃ and the vacuum degree is 4Pa, adjusting the heating rate to 20 ℃/min, simultaneously pressurizing, timing when the temperature is raised to 700 ℃, the pressure reaches 80MPa and the displacement rate variation of the sintered mixed powder is 0.03mm/min, and keeping the temperature and the pressure for 30 min; and then closing the heating system, simultaneously unloading the pressure at the speed of 5kN/s, and cooling to 240 ℃ along with the furnace to obtain the composite material block. After the composite material block is cooled to 90 ℃ in the air, firstly cleaning the surface of the composite material block by using deionized water, then cleaning the surface of the composite material block by using ethanol, and drying;

(3) sequentially polishing each surface of the composite material block cleaned and dried in the step (2) by using 80-mesh, 400-mesh, 1000-mesh and 2000-mesh sandpaper to remove an oxide film on the surface of the composite material block to obtain a blank; heating the blank at 1250 ℃ for 3min, then carrying out hot rolling by adopting a rolling mill with a flat roller as a roller, and carrying out seven-pass treatment, wherein the temperature of the roller is room temperature, the final rolling temperature of the hot rolling is 1080 ℃, the single-pass deformation is 10%, the rolling direction of each pass is vertical to that of the previous pass, and the total deformation is 70%; the heating temperature of each inter-pass remelting is 1100 ℃, and the heating time is 1 min; returning to the furnace and heating again after finishing rolling, wherein the heating temperature is 1050 ℃, and the heating time is 3 min; after heating, carrying out water quenching treatment by adopting a NaCl solution with the mass fraction of 15%, and cleaning and drying to obtain the bidirectional vertical alternating hot rolled block;

(4) and (3) vacuum packaging the bidirectional vertical hot rolled block obtained in the step (3) in a quartz tube, then placing the quartz tube into an OTF-1200X-S heat treatment furnace at 750 ℃ for heat treatment for 10min, then cooling the quartz tube to 100 ℃ along with the heat treatment furnace, taking out the quartz tube, and cleaning and drying the cooled product to obtain the TiB whisker reinforced titanium-based composite material.

The TiB whisker reinforced titanium-based composite material obtained in the example was prepared into a sample and tested, and the test results (see Table 2) were as follows:

a) the density of the TiB whisker reinforced titanium-based composite material is 99.8 percent;

b) the mechanical property of the TiB whisker reinforced titanium-based composite material is as follows: isotropy, the tensile strength of 1170MPa, the tensile yield strength of 1033MPa and the tensile elongation of 9.3 percent;

c) the analysis result of the SEM image of the composite material block prepared by spark plasma sintering in step (3) is as follows:

when the sintering temperature used is 700 ℃, the formation of the sintering necks and grain boundaries between the matrix particles has been completed, and the densification has been preliminary conducted. TC4 and TiB₂Has already been preparedA limited degree of in situ reaction takes place, unreacted TiB₂The phase and the TiB primary phase generated by the reaction are mixed and distributed at the position of the matrix grain boundary. Wherein unreacted TiB₂The phase is in an initial granular shape, and the TiB primary phase generated by the reaction is in a short whisker shape; obtained by analysis treatment, the average length is 0.5 μm, and the average length-diameter ratio is 18;

e) the analysis result of the SEM image of the TiB whisker reinforced titanium matrix composite material is as follows:

in the TiB whisker reinforced titanium-based composite material, the TiB whisker reinforced titanium-based composite material is obtained by analysis treatment, the average length-diameter ratio of the TiB whisker is 44, and the average diameter of the whisker is 105 nm; the reinforcing phase TiB nano crystal whiskers are uniformly distributed in the composite material in a three-dimensional net shape, the integrity is good, the crystal whiskers are free from abnormal coarsening, the interface with a matrix is clean, the bonding is firm, no preferred orientation exists in the tissue, and the load transfer effect can be effectively exerted.

Example 3

(1) 5.0g of TiB₂Adding powder and 15.0g of Ti powder into a ball milling tank of an SM-QB planetary ball mill, adding grinding balls and absolute ethyl alcohol according to a ball-to-material ratio of 10:1, carrying out ball milling treatment for 5 hours at the rotating speed of 150r/min to obtain uniformly mixed slurry, pouring the mixed slurry into a vacuum rotary evaporator, carrying out rotary evaporation for 2 hours at the temperature of 70 ℃ at 30r/min, and drying for 0.2 hour in an electric heating constant-temperature gulf drying cabinet at the temperature of 60 ℃ after acetone is volatilized completely to obtain mixed powder;

the grinding balls consist of large agate balls and small agate balls in a mass ratio of 10:1, the diameter ratio of the large agate balls to the small agate balls is 2:1, and the diameter of the small agate balls is 5 mm;

(2) putting 20g of the mixed powder obtained in the step (1) into a cylindrical graphite die with the inner diameter of 25mm, wherein the mixed powder is separated from the side wall of the die and a pressure head by 0.1mm of graphite foil, then putting the die into an SPS-3.20-MV discharge plasma system, setting the initial vacuum degree in a cranial cavity to be 5Pa, setting the initial pressure to be 0.1MPa, and heating at the heating rate of 200 ℃/min; when the temperature is increased to 850 ℃ and the vacuum degree is 5Pa, adjusting the heating rate to 50 ℃/min, simultaneously pressurizing, timing when the temperature is increased to 900 ℃, the pressure reaches 3MPa and the displacement rate variation of the sintered mixed powder is 0.02mm/min, and keeping the temperature and the pressure for 3 min; and then closing the heating system, simultaneously unloading the pressure at the speed of 0.1kN/s, and cooling to 200 ℃ along with the furnace to obtain the composite material block. After the composite material block is cooled to 80 ℃ in the air, firstly cleaning the surface of the composite material block by using deionized water, then cleaning the surface of the composite material block by using ethanol, and drying;

(3) sequentially polishing each surface of the composite material block cleaned and dried in the step (2) by using 100-mesh, 400-mesh, 1000-mesh, 1500-mesh and 2000-mesh sand paper to remove an oxide film on the surface of the composite material block to obtain a blank; heating the blank at 950 ℃ for 25min, then carrying out hot rolling by adopting a rolling mill with a flat roller, and carrying out seven-pass treatment, wherein the temperature of the roller is room temperature, the final temperature of the hot rolling is 780 ℃, the single-pass deformation is 4%, the rolling direction of each pass is vertical to that of the previous pass, and the total deformation is 28%; the heating temperature of each inter-pass remelting is 800 ℃, and the heating time is 10 min; returning to the furnace again for heating after finishing rolling, wherein the heating temperature is 950 ℃, and the heating time is 8 min; after heating, carrying out water quenching treatment by adopting a NaCl solution with the mass fraction of 5%, and cleaning and drying to obtain the bidirectional vertical alternating hot-rolled block;

(4) and (3) vacuum packaging the bidirectional vertical hot rolled block obtained in the step (3) in a quartz tube, then placing the quartz tube into an OTF-1200X-S heat treatment furnace at 450 ℃ for heat treatment for 240min, then cooling the quartz tube to 100 ℃ along with the heat treatment furnace, taking out the quartz tube, and cleaning and drying the cooled product to obtain the TiB whisker reinforced titanium-based composite material.

The TiB whisker reinforced titanium-based composite material obtained in the example was prepared into a sample and tested, and the test results (see Table 2) were as follows:

a) the density of the TiB whisker reinforced titanium-based composite material is 99.3 percent;

b) the mechanical property of the TiB whisker reinforced titanium-based composite material is as follows: isotropy, the tensile strength is 1032MPa, the tensile yield strength is 934MPa, and the tensile elongation is 8.1 percent;

c) the analysis result of the SEM image of the composite material block prepared by spark plasma sintering in step (3) is as follows:

when the sintering temperature of 900 ℃ is adopted, the sintering neck connection and the formation of grain boundaries between matrix particles are finished, and the densification is performed preliminarily. Ti and TiB₂Has a certain degree of in-situ reaction between, unreacted TiB₂The phase and the TiB primary phase generated by the reaction are mixed and distributed at the position of the matrix grain boundary. Wherein unreacted TiB₂The phase is in an initial granular shape, and the TiB primary phase generated by the reaction is in a short whisker shape; obtained by analysis treatment, the average length is 1.1 mu m, and the average length-diameter ratio is 22;

e) the analysis result of the SEM image of the TiB whisker reinforced titanium matrix composite material is as follows:

in the TiB whisker reinforced titanium-based composite material, the TiB whisker reinforced titanium-based composite material is obtained by analysis treatment, the average length-diameter ratio of the TiB whisker is 38, and the average diameter of the whisker is 90 nm; the strong phase TiB nano crystal whiskers are uniformly distributed in the composite material in a three-dimensional net shape, the integrity is good, the crystal whiskers are free from abnormal coarsening, the interface with a matrix is clean, the bonding is firm, no preferred orientation exists in the tissue, and the load transfer effect can be effectively exerted.

Comparative example 1

In patent application No. CN201810684391.1 (a method for preparing a TiB nano reinforced titanium matrix composite), a method for preparing a TiB nano reinforced titanium matrix composite comprises the following steps:

(1) 0.09g of nano TiB₂Adding the powder and 19.91g of TC4 powder into a ball milling tank of an SM-QB planetary ball mill, and adding grinding balls and excessive absolute ethyl alcohol according to a ball-to-material ratio of 4: 1; ball-milling for 2 hours at the rotating speed of 300r/min, and uniformly mixing to obtain mixed slurry; pouring the mixed slurry into a vacuum rotary evaporator, steaming for 2 hours under the conditions that the rotating speed is 40r/min and the water bath temperature is 70 ℃, and obtaining a mixed powder precursor after the ball milling medium is volatilized; putting the mixed powder precursor into an electric heating constant-temperature air blast drying box, and drying at 30 ℃ for 0.5h to obtain mixed powder;

the grinding ball consists of a large agate ball and a small agate ball in a mass ratio of 1:1, wherein the diameter of the large agate ball is 10mm, and the diameter of the small agate ball is 5 mm;

(2) putting 20g of mixed powder into a cylindrical hard alloy die with the inner diameter of 25mm, then putting the die into a discharge plasma sintering system, setting the initial vacuum degree in a furnace cavity to be 1Pa and the initial pressure to be 1MPa, heating at the heating rate of 200 ℃/min, adjusting the heating rate to be 50 ℃/min when the temperature is increased to 550 ℃ and the vacuum degree is 3Pa, simultaneously pressurizing, timing when the temperature is increased to 600 ℃, the pressure reaches 300MPa and the displacement rate change of the sintered mixed powder is 0.03mm/min, and keeping the temperature and the pressure for 10 min; and then keeping the pressure unchanged, cooling to 200 ℃ along with the furnace, removing the pressure, cooling to 80 ℃ along with the furnace, taking out the sintered composite material block, cleaning the surface of the composite material block by using deionized water, cleaning the surface of the composite material block by using ethanol, and drying.

(3) Heating the dried composite material block by a heating furnace, wherein the discharging temperature is 950 ℃, and the heating time is 5 min; then hot rolling by a rolling mill, wherein the roller is a flat roller and the temperature of the roller is room temperature; the hot rolling finishing temperature is 920 ℃, the hot rolling finishing temperature is divided into 4 passes, the single-pass deformation is 15 percent, and the total deformation is 60 percent; the time for reheating the furnace is 5min and the temperature of the reheating is 950 ℃; the TiB nano reinforced titanium-based composite material of the embodiment is obtained.

The TiB whisker-reinforced titanium-based composite material obtained in comparative example 1 was used as a test specimen to obtain test results (see Table 2).

Comparative example 2

Comparative example 2 is substantially the same as example 1 except that step 3 is:

sequentially polishing each surface of the composite material block cleaned and dried in the step (2) by using 80-mesh, 200-mesh, 600-mesh, 1000-mesh, 1500-mesh and 2000-mesh sandpaper to remove an oxide film on the surface of the composite material block to obtain a blank; heating the blank at 1050 ℃ for 6min, then carrying out hot rolling by adopting a rolling mill with a flat roller as a roller, and carrying out seven-pass treatment, wherein the temperature of the roller is room temperature, the final temperature of the hot rolling is 930 ℃, the single-pass deformation is 10%, the rolling direction of each pass is the same as that of the previous pass, and the total deformation is 70%; the heating temperature of each inter-pass remelting is 950 ℃, and the heating time is 1.5 min; returning to the furnace and heating again after finishing rolling, wherein the heating temperature is 1000 ℃, and the heating time is 5 min; and (3) after heating, performing water quenching treatment by adopting a NaCl solution with the mass fraction of 15%, and cleaning and drying to obtain the hot-rolled block.

The TiB whisker reinforced titanium-based composite material obtained in the comparative example 2 was used as a test sample to obtain test results (see Table 2).

Comparative example 3

Comparative example 3 is substantially the same as example 1 except that in step 3, two passes of treatment were carried out with a single pass deformation of 35%.

The TiB whisker reinforced titanium-based composite material obtained in the comparative example 3 was used as a test sample to obtain test results (see Table 2).

As compared with examples 1 to 3, it was found that the composite material block obtained by spark plasma sintering in comparative example 1 was different from the composite material block obtained by sintering in examples 1 to 3 of the present invention in the state of being different from each other; and bidirectional vertical alternate hot rolling is not adopted in the hot rolling process, so that the TiB nano reinforced titanium-based composite material has anisotropy, and the mechanical properties are different in different directions, the comparative example 1 solves the problems of TiB whisker coarsening, low length-diameter ratio and agglomeration caused by mixing of the TiB whisker and an unreacted boride raw material, and does not solve the problem of influencing the structural integrity of a TiB whisker reinforced phase when the matrix structure of the titanium-based composite material is adjusted by hot working and heat treatment.

Compared with examples 1 to 3, the TiB whisker reinforced titanium matrix composite material obtained in comparative example 2 has anisotropy and different mechanical properties in different directions. Compared with the example 1, the comparison of the comparative example 3 and the example 1 shows that under the condition that the total deformation is the same, the elongation and the hardness of the composite material are higher, the strength is higher and the comprehensive performance is good when the rolling passes are more. Meanwhile, the small deformation has little effect on the anisotropy of the composite material; the material flow during rolling with large deformation is in a strip shape, the material flow during rolling with small deformation is in a beam shape, and the distortion of the composite material obtained by cogging with large deformation is serious under the condition that the heat treatment conditions between passes are the same as those of the subsequent rolling process.

TABLE 2

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.