Gap-strengthened titanium-based composite material with room-temperature strength and plasticity matched with high-temperature strength and preparation method of gap-strengthened titanium-based composite material

Abstract

The invention relates to a gap strengthening titanium-based composite material with room-temperature strength and plasticity matched with high-temperature strength and a preparation method of the gap strengthening titanium-based composite material, and belongs to the technical field of titanium-based composite materials. In order to solve the problem that an existing method for introducing interstitial elements into a titanium-based composite material is difficult to achieve uniform distribution of the interstitial elements, the method comprises the steps that firstly, interstitial element additive powder, reinforced phase reactant powder and titanium alloy matrix powder are mixed and subjected to ball milling to obtain raw material powder, and the raw material powder is prepared into a raw material bar through hot pressing sintering or hot isostatic pressing; preparing the raw material bar into interstitial element reinforced titanium-based composite powder through plasma rotating electrode atomization powder preparation; and finally, the obtained titanium-based composite powder is subjected to hot pressing sintering or hot isostatic pressing, and the gap strengthening titanium-based composite material is obtained. According to the method, the interstitial elements are introduced into the titanium-based composite powder in situ, the content and distribution of the interstitial elements are accurately regulated and controlled, the obtained series of titanium-based composite materials have good strength and plasticity matching at the room temperature, and the high-temperature strength is also greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium-based composite materials, and in particular relates to a gap-reinforced titanium-based composite material with matched room temperature strong plasticity and high temperature strength and a preparation method thereof. Background Art

[0002] As a kind of advanced structural material, titanium-based composites have shown broad application prospects in aerospace, automobile manufacturing, medical equipment, energy and other fields due to their high specific strength, high specific stiffness, excellent high-temperature performance and good corrosion resistance. Titanium-based composites are mainly composed of high-performance reinforcing phases, such as ceramic particles, fibers, etc. and titanium alloy matrix. The introduction of reinforcing phases is aimed at improving the mechanical properties of the material, including strength, hardness and wear resistance. Although the introduction of reinforcing phases can improve the high-temperature strength of the material, it may also lead to a decrease in room-temperature plasticity. How to balance high-temperature strength and room-temperature strength and plasticity is a difficult problem in the design of titanium-based composites.

[0003] In addition to the reinforcing phase, interstitial elements in titanium-based composites also have a significant impact on the performance of the material. Interstitial elements usually refer to atoms or ions that can fill the gaps in the metal or alloy lattice. An appropriate amount of interstitial elements can increase the resistance to dislocation movement by causing lattice distortion, thereby increasing the yield strength and tensile strength of the material. However, excessive amounts of interstitial elements can cause excessive lattice distortion, increase the difficulty of dislocation movement, reduce the toughness of titanium-based composites, and make them more prone to fracture during plastic deformation. It can be seen that the reasonable regulation of the content and distribution of interstitial elements is crucial to the performance of titanium-based composites.

[0004] For the reinforcement phase, micron-nano design can reduce plastic loss or even increase the plasticity of the material while ensuring strength improvement. However, the content and distribution of interstitial elements in alloys are often small and difficult to control accurately. Even a small change in content may have a significant impact on the performance of the material. Therefore, strict process control is required to achieve precise regulation of interstitial elements.

[0005] Traditional methods of introducing interstitial elements into titanium alloys and titanium-based composites are mostly to decompose oxides, nitrides and carbides through smelting, or to diffuse them through ball milling and high-temperature sintering. However, titanium-based composites prepared by ball milling combined with high-temperature sintering often have a large range of non-uniform structures, and are prone to coarsening of the structure, especially in titanium-based composites containing nano-reinforced phases, which will cause the rapid growth of the reinforcement phase and cause performance degradation, making it difficult to ensure the uniformity of large-size components, and it is impossible to take into account both room temperature plasticity and high-temperature strength. Moreover, due to the strong atomic bonding between oxides, nitrides and carbides, it is often necessary to repeatedly melt or sinter at high temperature for a long time to ensure their complete decomposition and uniform diffusion. This places strict requirements on the preparation process of titanium-based composites, limiting their large-scale application and development. Summary of the invention

[0006] In order to solve the problem that the existing method of introducing interstitial elements into titanium-based composite materials is difficult to achieve uniform distribution of interstitial elements, resulting in mismatch between room temperature strength and plasticity and high temperature strength of titanium-based composite materials, and the preparation method is inefficient, the present invention provides an interstitial reinforced titanium-based composite material with matched room temperature strength and plasticity and high temperature strength and a preparation method thereof.

[0007] The technical solution of the present invention:

[0008] A method for preparing a gap-reinforced titanium-based composite material having matched room temperature ductility and high temperature strength comprises the following steps:

[0009] Step 1: Prepare raw material powder:

[0010] Oxygen, nitrogen or carbon is used as interstitial element, TiB, La2O3 or Y2O3 is used as reinforcing phase; interstitial element additive powder, reinforcing phase reactant powder and titanium alloy matrix powder are weighed according to the designed interstitial element content and reinforcing phase content, and the interstitial element additive powder, reinforcing phase reactant powder and titanium alloy matrix powder are mixed and ball-milled to obtain raw material powder;

[0011] Step 2: Preparation of interstitial element reinforced titanium-based composite powder:

[0012] The raw material powder obtained by ball milling is subjected to hot pressing sintering or hot isostatic pressing to obtain a raw material rod, and then powdered by plasma rotating electrode atomization to obtain a titanium-based composite powder reinforced with interstitial elements;

[0013] Step 3: Preparation of gap-reinforced titanium-based composite materials:

[0014] The obtained interstitial element reinforced titanium-based composite powder is subjected to hot pressing sintering or hot isostatic pressing to obtain an interstitial reinforced titanium-based composite material.

[0015] Furthermore, the particle size of the interstitial element additive powder in step 1 is 50 nm, 100 nm, 1 μm, 2 μm, 3 μm or 5 μm, when the interstitial element is oxygen, the corresponding additive powder is TiO2 powder, when the interstitial element is nitrogen, the corresponding additive powder is TiN powder, and when the interstitial element is carbon, the corresponding additive powder is graphite powder;

[0016] The particle size of the reinforcing phase reactant powder in step 1 is 50 nm, 100 nm, 1 μm, 2 μm, 3 μm or 5 μm. When the reinforcing phase is TiB, the reinforcing phase reactant powder is TiB2, ZrB2 or BN powder. When the reinforcing phase is La2O3, the reinforcing phase reactant powder is La2O3 or LaB6 powder. When the reinforcing phase is Y2O3, the reinforcing phase reactant powder is Y2O3 powder.

[0017] The particle size distribution range of the titanium alloy matrix powder is 1-75μm, 1-53μm, 75-150μm, 53-180μm, 150-250μm, 1-150μm, 1-180μm or 1-250μm, and the titanium alloy matrix powder is Ti, TC4, TA15, Ti65, Ti60, Ti55 or TC11 powder.

[0018] Furthermore, the rotation speed of the ball mill in step 1 is 100-400 r / min, the mass ratio of the material to the steel ball during ball milling is 1:1-7, the diameter of the steel ball is 6 mm or 10 mm, the ball milling time is 2-8 h, and the ball mill rotation mode is forward, reverse or alternating forward and reverse.

[0019] Furthermore, the hot pressing sintering in step 2 is to place the raw material powder obtained in step 1 in a mold for sintering, the sintering temperature is 1200-1400°C, the pressure is 10-40MPa, and the sintering time is 1.5-2.5h; the hot isostatic pressing is to place the raw material powder obtained in step 1 in a titanium sheath, the sintering temperature is 1200-1400°C, the pressure is 100-200MPa, and the sintering time is 1.5-2.5h.

[0020] Furthermore, the processing diameter of the raw material bar in step 2 is 25 mm, 50 mm or 75 mm.

[0021] Furthermore, in step 2, the feed speed of the plasma rotating electrode atomization powder making is 0.5-3 mm / s, the arc current is 1500-3000 A, and the rod rotation speed is 10000-30000 r / min.

[0022] Furthermore, the particle size distribution range of the interstitial element reinforced titanium-based composite powder obtained by atomization powder making in step 2 is 1-75 μm, 1-53 μm, 75-150 μm, 53-180 μm, 150-250 μm, 1-150 μm, 1-180 μm or 1-250 μm.

[0023] Furthermore, the hot pressing sintering in step three is to place the interstitial element reinforced titanium-based composite powder obtained in step two in a mold for sintering, the sintering temperature is 950-1100°C, the pressure is 20-80MPa, and the sintering time is 1-10h; the hot isostatic pressing is to place the interstitial element reinforced titanium-based composite powder obtained in step two in a titanium sheath, the sintering temperature is 900-1100°C, the pressure is 100-200MPa, and the sintering time is 1-10h.

[0024] The invention provides a gap-reinforced titanium-based composite material with matched room temperature ductility and high temperature strength, wherein the gap element content is 0.01-1wt% and the reinforcement phase content is 0.1-6vol.%.

[0025] Furthermore, when the interstitial element is oxygen, the content of oxygen is 0.15-0.25 wt %; when the interstitial element is nitrogen, the content of nitrogen is 0.075-0.15 wt %; when the interstitial element is carbon, the content of carbon is 0.03-0.2 wt %.

[0026] Beneficial effects of the present invention:

[0027] The present invention provides a method for in-situ introduction of interstitial elements into titanium-based composite powders in order to simplify the preparation process of interstitial element reinforced titanium-based composite materials and increase the process window. The method can ensure that the interstitial element atoms are evenly dispersed in the powder. Combined with the powder metallurgy process, the precise regulation of the interstitial element content and distribution is achieved, and the performance degradation caused by element segregation is effectively avoided. The controllability and stability of the performance of the titanium-based composite materials are greatly improved. The obtained series of titanium-based composite materials have good strength-plasticity matching at room temperature and greatly improved high-temperature strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a microscopic photograph of the reinforced titanium-based composite powder in Example 1 in which the interstitial element is oxygen;

[0029] Figure 2 The micrographs of the cross-sectional structures of the reinforced titanium-based composite powders with oxygen as the interstitial element in Examples 1-3 are magnified at different times;

[0030] Figure 3 This is an oxygen element scanning diagram of the cross-sectional structure of the reinforced titanium-based composite powder in Example 1 where the interstitial element is oxygen;

[0031] Figure 4 The organization diagram of the titanium-based composite material in which the interstitial element is oxygen element in Example 3, the left diagram is a SEM diagram, and the right diagram is an IPF diagram;

[0032] Figure 5 This is a comparison chart of room temperature performance of titanium-based composite materials in which the interstitial element is oxygen element in Examples 1-3;

[0033] Figure 6 This is a comparison chart of high temperature performance of titanium-based composite materials in which the interstitial element is oxygen element in Examples 1-3;

[0034] Figure 7 This is a micrograph of the cross-sectional structure of the reinforced titanium-based composite powder in Example 4-5 where the interstitial element is nitrogen;

[0035] Figure 8 The organization diagram of the titanium-based composite material in Example 5 in which the interstitial element is nitrogen, the left diagram is a SEM diagram, and the right diagram is an IPF diagram;

[0036] Fig. 9 This is a comparison chart of room temperature performance of titanium-based composite materials in which the interstitial element is nitrogen in Examples 4-5;

[0037] Fig.10 This is a comparison chart of high temperature performance of titanium-based composite materials in which the interstitial element is nitrogen in Examples 4-5;

[0038] Fig.11 This is a comparison chart of room temperature performance of titanium-based composite materials in which the interstitial element is carbon in Examples 6-7;

[0039] Fig.12 This is a microscopic photograph of the metallographic structure of the O-containing titanium-based composite material of Comparative Example 1. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described below in conjunction with the embodiments, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be included in the protection scope of the present invention. The process equipment or devices not specifically noted in the following embodiments are all conventional equipment or devices in the art. If not specifically specified, the raw materials used in the embodiments of the present invention can be obtained commercially; if not specifically specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0041] Example 1

[0042] This embodiment provides a titanium-based composite material in which an interstitial element is oxygen and a preparation method thereof.

[0043] In this embodiment, the interstitial element is oxygen, the corresponding additive powder is TiO2 powder with a particle size of 50nm, the reinforcement phase is TiB, and the reinforcement phase reactant powder is TiB2 powder with a particle size of 5μm; the titanium alloy matrix is ​​TA15 powder with a particle size distribution range of 75-150μm. In this embodiment, the volume fraction of the reinforcement phase TiB is designed to be 1vol.%, and the mass fraction of the interstitial element O is 0.15wt%, which is recorded as 1TiB+0.15O / TA15 or 1vol.%TiB+0.15wt%O+TA15.

[0044] The specific steps of the preparation method of the titanium-based composite material in which the interstitial element is oxygen element in this embodiment are as follows:

[0045] Step 1: Prepare raw material powder:

[0046] According to the designed interstitial element content and reinforcing phase content, 3 kg of TA15 powder, 17.6470 g of TiB2 powder, and 7.5065 g of TiO2 powder were weighed, all of the weighed powders were placed in a ball mill, which was sealed and flushed with high-purity argon gas, and then ball milled at a speed of 220 r / min, a mass ratio of material to steel ball of 1:5, a diameter of the steel ball of 10 mm, a ball milling time of 4 h, and a forward rotation mode to obtain raw material powder;

[0047] Step 2: Preparation of interstitial element reinforced titanium-based composite powder:

[0048] The raw powder obtained by ball milling in step 1 is placed in a mold for hot pressing and sintering. The sintering temperature is 1200°C, the pressure is 20MPa, and the sintering time is 2h to obtain a cylindrical raw material rod. The oxide layer on the surface of the raw material rod is removed by a lathe, and the rod is processed according to a fixed size to meet the rod diameter of 75mm. One end of the rod is processed to obtain a thread that cooperates with the powder making machine. The processed raw material rod is cleaned and assembled on a plasma rotating electrode atomization powder making machine. When the atomization chamber is filled with high-purity argon gas, atomization and powder making begins. The feed speed is 1.1mm / s, the arc current is 2600A, and the rod rotation speed is 20000r / min. The obtained powder is first freed of impurities and screened to obtain a powder with a particle size distribution range of 75 to 150μm to obtain an interstitial element reinforced titanium-based composite powder with a surface morphology such as Figure 1 As shown, the obtained interstitial element reinforced titanium-based composite powder particles are mostly regular spherical and have a smooth surface.

[0049] Step 3: Preparation of gap-reinforced titanium-based composite materials:

[0050] The interstitial element reinforced titanium-based composite powder obtained in step 2 is placed in a mold for hot pressing sintering at a sintering temperature of 1000° C., a pressure of 60 MPa, and a sintering time of 6 h. After removing the mold, an interstitial reinforced titanium-based composite material is obtained.

[0051] Example 2

[0052] This embodiment provides a titanium-based composite material in which an interstitial element is oxygen and a preparation method thereof.

[0053] In this embodiment, the interstitial element is oxygen, the corresponding additive powder is TiO2 powder with a particle size of 50nm, the reinforcing phase is TiB, and the reinforcing phase reactant powder is TiB2 powder with a particle size of 5μm; the titanium alloy matrix is ​​TA15 powder with a particle size distribution range of 75-150μm. In this embodiment, the volume fraction of the reinforcing phase TiB is designed to be 1vol.%, and the mass fraction of the interstitial element O is 0.2wt%, which is recorded as 1TiB+0.2O / TA15 or 1vol.%TiB+0.20wt%O+TA15.

[0054] The specific steps of the preparation method of the titanium-based composite material in which the interstitial element is oxygen element in this embodiment are as follows:

[0055] Step 1: Prepare raw material powder:

[0056] According to the designed interstitial element content and reinforcing phase content, 3 kg of TA15 powder, 17.6470 g of TiB2 powder, and 11.2739 g of TiO2 powder were weighed, all of the weighed powders were placed in a ball mill, which was sealed and flushed with high-purity argon gas, and then ball milled at a speed of 220 r / min, a mass ratio of material to steel ball of 1:5, a diameter of the steel ball of 10 mm, a ball milling time of 4 h, and a forward rotation mode to obtain raw material powder;

[0057] Step 2: Preparation of interstitial element reinforced titanium-based composite powder:

[0058] The raw material powder obtained by ball milling in step 1 is placed in a mold for hot pressing and sintering. The sintering temperature is 1200℃, the pressure is 20MPa, and the sintering time is 2h to obtain a cylindrical raw material bar. The surface oxide layer of the raw material bar is removed by lathe, and it is processed according to a fixed size to meet the diameter of the bar of 75mm. One end of the bar is processed to obtain a thread that cooperates with the powder making machine. The processed raw material bar is cleaned and assembled on a plasma rotating electrode atomizing powder making machine. When the atomizing chamber is filled with high-purity argon gas, atomization and powder making begins. The feed speed is 1.1mm / s, the arc current is 2600A, and the rod rotation speed is 20000r / min. The obtained powder is firstly removed of impurities, and the powder with a particle size distribution range of 75 to 150μm is screened to obtain a titanium-based composite powder reinforced with interstitial elements.

[0059] Step 3: Preparation of gap-reinforced titanium-based composite materials:

[0060] The interstitial element reinforced titanium-based composite powder obtained in step 2 is placed in a mold for hot pressing sintering at a sintering temperature of 1000° C., a pressure of 60 MPa, and a sintering time of 6 h. After removing the mold, an interstitial reinforced titanium-based composite material is obtained.

[0061] Example 3

[0062] This embodiment provides a titanium-based composite material in which an interstitial element is oxygen and a preparation method thereof.

[0063] In this embodiment, the interstitial element is oxygen, the corresponding additive powder is TiO2 powder with a particle size of 50nm, the reinforcing phase is TiB, and the reinforcing phase reactant powder is TiB2 powder with a particle size of 5μm; the titanium alloy matrix is ​​TA15 powder with a particle size distribution range of 75-150μm. In this embodiment, the volume fraction of the reinforcing phase TiB is designed to be 1vol.%, and the mass fraction of the interstitial element O is 0.25wt%, which is recorded as 1TiB+0.25O / TA15 or 1vol.%TiB+0.25wt%O+TA15.

[0064] The specific steps of the preparation method of the titanium-based composite material in which the interstitial element is oxygen element in this embodiment are as follows:

[0065] Step 1: Prepare raw material powder:

[0066] According to the designed interstitial element content and reinforcing phase content, 3 kg of TA15 powder, 17.6470 g of TiB2 powder, and 15.0508 g of TiO2 powder were weighed, all of the weighed powders were placed in a ball mill, which was sealed and flushed with high-purity argon gas, and then ball milled at a speed of 220 r / min, a mass ratio of material to steel ball of 1:5, a diameter of the steel ball of 10 mm, a ball milling time of 4 h, and a forward rotation mode to obtain raw material powder;

[0067] Step 2: Preparation of interstitial element reinforced titanium-based composite powder:

[0068] The raw material powder obtained by ball milling in step 1 is placed in a mold for hot pressing and sintering. The sintering temperature is 1200℃, the pressure is 20MPa, and the sintering time is 2h to obtain a cylindrical raw material bar. The surface oxide layer of the raw material bar is removed by lathe, and it is processed according to a fixed size to meet the diameter of the bar of 75mm. One end of the bar is processed to obtain a thread that cooperates with the powder making machine. The processed raw material bar is cleaned and assembled on a plasma rotating electrode atomizing powder making machine. When the atomizing chamber is filled with high-purity argon gas, atomization and powder making begins. The feed speed is 1.1mm / s, the arc current is 2600A, and the rod rotation speed is 20000r / min. The obtained powder is firstly removed of impurities, and the powder with a particle size distribution range of 75 to 150μm is screened to obtain a titanium-based composite powder reinforced with interstitial elements.

[0069] Step 3: Preparation of gap-reinforced titanium-based composite materials:

[0070] The interstitial element reinforced titanium-based composite powder obtained in step 2 is placed in a mold for hot pressing sintering at a sintering temperature of 1000° C., a pressure of 60 MPa, and a sintering time of 6 h. After removing the mold, an interstitial reinforced titanium-based composite material is obtained.

[0071] Figure 2The micrographs of the cross-sectional structure of the reinforced titanium-based composite powder with oxygen as the interstitial element in Examples 1-3 are magnified at different times; Figure 2 It can be seen that the prepared oxygen-reinforced titanium-based composite material powder contains nano-scale TiB, which is beneficial to the strength-plasticity matching of the material, and its structure is uniform and free of defects, which is conducive to sintering. Figure 3 This is an oxygen element scanning diagram of the cross-sectional structure of the reinforced titanium-based composite powder in Example 1 where the interstitial element is oxygen; Figure 3 It can be seen that the O element is evenly distributed in the powder.

[0072] Figure 4 The organization diagram of the titanium-based composite material in which the interstitial element is oxygen element in Example 3, the left diagram is the SEM diagram and the right diagram is the IPF diagram; Figure 4 It can be seen that the oxygen-reinforced titanium-based composite material obtained by sintering has a fine and uniform structure without any tiny defects, which is conducive to the strengthening and plasticization of the material.

[0073] Figure 5 The room temperature performance comparison diagram of the titanium-based composite material with oxygen as the interstitial element in Examples 1-3 is shown in FIG. Figure 5 It can be seen that the oxygen-reinforced titanium-based composites have good strength-plasticity matching at room temperature.

[0074] The yield strength, ultimate strength and elongation of the titanium-based composite materials of Examples 1-3 whose interstitial elements are oxygen elements are shown in Table 1.

[0075] Table 1

[0076] Test items Yield strength MPa Ultimate strength MPa Elongation % Example 1 973 1053 18.8 Example 2 1017 1098 17.1 Example 3 1049 1121 17.2

[0077] Figure 6 is a comparison chart of high temperature performance of titanium-based composite materials whose interstitial elements are oxygen elements in Examples 1-3; Figure 6 It can be seen that the oxygen-reinforced titanium-based composite material has good high-temperature strength within 600-700°C.

[0078] Example 4

[0079] This embodiment provides a titanium-based composite material in which an interstitial element is nitrogen and a preparation method thereof.

[0080] In this embodiment, the interstitial element is nitrogen, the corresponding additive powder is TiN powder with a particle size of 1 μm, the reinforcement phase is TiB, and the reinforcement phase reactant powder is TiB2 powder with a particle size of 5 μm; the titanium alloy matrix is ​​TA15 powder with a particle size distribution range of 75-150 μm. In this embodiment, the volume fraction of the reinforcement phase TiB is designed to be 1 vol.%, and the mass fraction of the interstitial element N is 0.075 wt%, which is recorded as 1TiB+0.075N / TA15 or 1 vol.%TiB+0.075wt%N+TA15.

[0081] The specific steps of the preparation method of the titanium-based composite material in which the interstitial element is nitrogen in this embodiment are as follows:

[0082] Step 1: Prepare raw material powder:

[0083] According to the designed interstitial element content and reinforcing phase content, 3 kg of TA15 powder, 17.6470 g of TiB2 powder, and 9.9765 g of TiN powder were weighed, all of the weighed powders were placed in a ball mill, which was sealed and flushed with high-purity argon gas, and then ball milled at a speed of 220 r / min, a mass ratio of material to steel ball of 1:5, a diameter of the steel ball of 10 mm, a ball milling time of 4 h, and a forward rotation mode to obtain raw material powder;

[0084] Step 2: Preparation of interstitial element reinforced titanium-based composite powder:

[0085] The raw material powder obtained by ball milling in step 1 is placed in a mold for hot pressing and sintering. The sintering temperature is 1300℃, the pressure is 20MPa, and the sintering time is 2h to obtain a cylindrical raw material bar. The surface oxide layer of the raw material bar is removed by lathe, and it is processed according to a fixed size to meet the diameter of the bar of 75mm. One end of the bar is processed to obtain a thread that cooperates with the powder making machine. The processed raw material bar is cleaned and assembled on a plasma rotating electrode atomizing powder making machine. When the atomizing chamber is filled with high-purity argon gas, atomization and powder making begins. The feed speed is 1.1mm / s, the arc current is 2600A, and the rod rotation speed is 20000r / min. The obtained powder is firstly removed of impurities, and the powder with a particle size distribution range of 75 to 150μm is screened to obtain a titanium-based composite powder reinforced with interstitial elements.

[0086] Step 3: Preparation of gap-reinforced titanium-based composite materials:

[0087] The interstitial element reinforced titanium-based composite powder obtained in step 2 is placed in a mold for hot pressing sintering at a sintering temperature of 1000° C., a pressure of 60 MPa, and a sintering time of 6 h. After removing the mold, an interstitial reinforced titanium-based composite material is obtained.

[0088] Example 5

[0089] This embodiment provides a titanium-based composite material in which an interstitial element is nitrogen and a preparation method thereof.

[0090] In this embodiment, the interstitial element is nitrogen, the corresponding additive powder is TiN powder with a particle size of 1 μm, the reinforcement phase is TiB, and the reinforcement phase reactant powder is TiB2 powder with a particle size of 5 μm; the titanium alloy matrix is ​​TA15 powder with a particle size distribution range of 75-150 μm. In this embodiment, the volume fraction of the reinforcement phase TiB is designed to be 1 vol.%, and the mass fraction of the interstitial element N is 0.15 wt%, which is recorded as 1TiB+0.15N / TA15 or 1 vol.%TiB+0.15wt%N+TA15.

[0091] The specific steps of the preparation method of the titanium-based composite material in which the interstitial element is nitrogen in this embodiment are as follows:

[0092] Step 1: Prepare raw material powder:

[0093] According to the designed interstitial element content and reinforcing phase content, 3 kg of TA15 powder, 17.6470 g of TiB2 powder, and 20.0195 g of TiN powder were weighed, all of the weighed powders were placed in a ball mill, which was sealed and flushed with high-purity argon gas, and then ball milled at a speed of 220 r / min, a mass ratio of material to steel ball of 1:5, a diameter of the steel ball of 10 mm, a ball milling time of 4 h, and a forward rotation mode to obtain raw material powder;

[0094] Step 2: Preparation of interstitial element reinforced titanium-based composite powder:

[0095] The raw material powder obtained by ball milling in step 1 is placed in a mold for hot pressing and sintering. The sintering temperature is 1300℃, the pressure is 20MPa, and the sintering time is 2h to obtain a cylindrical raw material bar. The surface oxide layer of the raw material bar is removed by lathe, and it is processed according to a fixed size to meet the diameter of the bar of 75mm. One end of the bar is processed to obtain a thread that cooperates with the powder making machine. The processed raw material bar is cleaned and assembled on a plasma rotating electrode atomizing powder making machine. When the atomizing chamber is filled with high-purity argon gas, atomization and powder making begins. The feed speed is 1.1mm / s, the arc current is 2600A, and the rod rotation speed is 20000r / min. The obtained powder is firstly removed of impurities, and the powder with a particle size distribution range of 75 to 150μm is screened to obtain a titanium-based composite powder reinforced with interstitial elements.

[0096] Step 3: Preparation of gap-reinforced titanium-based composite materials:

[0097] The interstitial element reinforced titanium-based composite powder obtained in step 2 is placed in a mold for hot pressing sintering at a sintering temperature of 1000° C., a pressure of 60 MPa, and a sintering time of 6 h. After removing the mold, an interstitial reinforced titanium-based composite material is obtained.

[0098] Figure 7The micrograph of the cross-sectional structure of the reinforced titanium-based composite powder in Example 4-5 where the interstitial element is nitrogen; Figure 7 It can be seen that the prepared nitrogen-reinforced titanium-based composite material powder contains nano-scale TiB, which is beneficial to the strength-plasticity matching of the material, and its structure is uniform and free of defects, which is conducive to sintering.

[0099] Figure 8 The organization diagram of the titanium-based composite material with nitrogen as the interstitial element in Example 5, the left diagram is the SEM diagram and the right diagram is the IPF diagram. Figure 8 It can be seen that the nitrogen-reinforced titanium-based composite material obtained by sintering has a fine and uniform structure without any tiny defects, which is beneficial to the strengthening and plasticization of the material.

[0100] Fig. 9 is a comparison chart of room temperature performance of titanium-based composite materials with nitrogen as interstitial element in Examples 4-5; Fig. 9 It can be seen that the titanium-based composites reinforced with nitrogen have good strength-plasticity matching at room temperature.

[0101] The yield strength, ultimate strength and elongation of the titanium-based composite material of Example 4-5 whose interstitial element is nitrogen are shown in Table 2.

[0102] Table 2

[0103] Test items Yield strength MPa Ultimate strength MPa Elongation % Example 4 967 1072 17.0 Example 5 1072 1133 5.1

[0104] Fig.10 is a comparison chart of high temperature performance of titanium-based composite materials whose interstitial elements are nitrogen in Examples 4-5; Fig.10 It can be seen that the nitrogen-reinforced titanium-based composite material has good high-temperature strength within 600-700°C.

[0105] Example 6

[0106] This embodiment provides a titanium-based composite material in which an interstitial element is carbon and a preparation method thereof.

[0107] In this embodiment, the interstitial element is carbon, the corresponding additive powder is graphite powder with a particle size of 1 μm, the reinforcement phase is TiB, and the reinforcement phase reactant powder is TiB2 powder with a particle size of 5 μm; the titanium alloy matrix is ​​TC4 powder with a particle size distribution range of 75-150 μm. In this embodiment, the volume fraction of the reinforcement phase TiB is designed to be 1 vol.%, and the mass fraction of the interstitial element C is 0.2 wt%, which is recorded as 1 vol.% TiB+0.2 wt% C+TC4.

[0108] The specific steps of the preparation method of the titanium-based composite material in which the interstitial element is carbon are as follows:

[0109] Step 1: Prepare raw material powder:

[0110] According to the designed interstitial element content and reinforcing phase content, 3 kg of TC4 powder, 17.6470 g of TiB2 powder, and 0.6 g of graphite powder were weighed, all of the weighed powders were placed in a ball mill, which was sealed and flushed with high-purity argon gas, and then ball milled at a speed of 220 r / min, a mass ratio of material to steel ball of 1:5, a diameter of the steel ball of 10 mm, a ball milling time of 4 h, and a forward rotation mode to obtain a raw material powder;

[0111] Step 2: Preparation of interstitial element reinforced titanium-based composite powder:

[0112] The raw material powder obtained by ball milling in step 1 is placed in a mold for hot pressing and sintering. The sintering temperature is 1300℃, the pressure is 20MPa, and the sintering time is 2h to obtain a cylindrical raw material bar. The surface oxide layer of the raw material bar is removed by lathe, and it is processed according to a fixed size to meet the diameter of the bar of 75mm. One end of the bar is processed to obtain a thread that cooperates with the powder making machine. The processed raw material bar is cleaned and assembled on a plasma rotating electrode atomizing powder making machine. When the atomizing chamber is filled with high-purity argon gas, atomization and powder making begins. The feed speed is 1.1mm / s, the arc current is 2600A, and the rod rotation speed is 20000r / min. The obtained powder is firstly removed of impurities, and the powder with a particle size distribution range of 75 to 150μm is screened to obtain a titanium-based composite powder reinforced with interstitial elements.

[0113] Step 3: Preparation of gap-reinforced titanium-based composite materials:

[0114] The interstitial element reinforced titanium-based composite powder obtained in step 2 is placed in a mold for hot pressing sintering at a sintering temperature of 1000° C., a pressure of 60 MPa, and a sintering time of 6 h. After removing the mold, an interstitial reinforced titanium-based composite material is obtained.

[0115] Example 7

[0116] This embodiment provides a titanium-based composite material in which an interstitial element is carbon and a preparation method thereof.

[0117] In this embodiment, the interstitial element is carbon, the corresponding additive powder is graphite powder with a particle size of 1 μm, the reinforcement phase is TiB, and the reinforcement phase reactant powder is TiB2 powder with a particle size of 5 μm; the titanium alloy matrix is ​​TC4 powder with a particle size distribution range of 75-150 μm. In this embodiment, the volume fraction of the reinforcement phase TiB is designed to be 0.5 vol.%, and the mass fraction of the interstitial element C is 0.03 wt%, which is recorded as 0.5 vol.% TiB+0.03 wt% C+TC4.

[0118] The specific steps of the preparation method of the titanium-based composite material in which the interstitial element is carbon are as follows:

[0119] Step 1: Prepare raw material powder:

[0120] According to the designed interstitial element content and reinforcing phase content, 3 kg of TC4 powder, 8.8235 g of TiB2 powder, and 0.09 g of graphite powder were weighed, all of the weighed powders were placed in a ball mill, which was sealed and flushed with high-purity argon gas, and then ball milled at a speed of 220 r / min, a mass ratio of material to steel ball of 1:5, a diameter of the steel ball of 10 mm, a ball milling time of 4 h, and a forward rotation mode to obtain a raw material powder;

[0121] Step 2: Preparation of interstitial element reinforced titanium-based composite powder:

[0122] The raw material powder obtained by ball milling in step 1 is placed in a mold for hot pressing and sintering. The sintering temperature is 1300℃, the pressure is 20MPa, and the sintering time is 2h to obtain a cylindrical raw material bar. The surface oxide layer of the raw material bar is removed by lathe, and it is processed according to a fixed size to meet the diameter of the bar of 75mm. One end of the bar is processed to obtain a thread that cooperates with the powder making machine. The processed raw material bar is cleaned and assembled on a plasma rotating electrode atomizing powder making machine. When the atomizing chamber is filled with high-purity argon gas, atomization and powder making begins. The feed speed is 1.1mm / s, the arc current is 2600A, and the rod rotation speed is 20000r / min. The obtained powder is firstly removed of impurities, and the powder with a particle size distribution range of 75 to 150μm is screened to obtain a titanium-based composite powder reinforced with interstitial elements.

[0123] Step 3: Preparation of gap-reinforced titanium-based composite materials:

[0124] The interstitial element reinforced titanium-based composite powder obtained in step 2 is placed in a mold for hot pressing sintering at a sintering temperature of 1000° C., a pressure of 60 MPa, and a sintering time of 6 h. After removing the mold, an interstitial reinforced titanium-based composite material is obtained.

[0125] Fig.11 is a comparison chart of room temperature performance of titanium-based composite materials whose interstitial elements are carbon elements in Examples 6-7; Fig.11 It can be seen that the carbon-reinforced titanium-based composites have good strength-plasticity matching at room temperature.

[0126] The yield strength, ultimate strength and elongation of the titanium-based composite material in Example 6-7 whose interstitial element is carbon are shown in Table 3.

[0127] Table 3

[0128] Test items Yield strength MPa Ultimate strength MPa Elongation % Example 6 966 1103 6.6 Example 7 954 1058 19.9

[0129] Comparative Example 1

[0130] This comparative example provides a method for preparing an O-containing titanium-based composite material by ball milling and high-temperature sintering, which is as follows:

[0131] Step 1: Ball milling:

[0132] Weigh 3 kg of TA15 powder with a particle size distribution range of 75-150 μm, 17.6470 g of TiB2 powder with a particle size of 5 μm, and 7.5065 g of TiO2 powder with a particle size of 50 nm, put all the weighed powders into a ball mill, seal it, and inject high-purity argon gas, then perform ball milling treatment, the ball milling speed is 220 r / min, the mass ratio of the material to the steel ball during ball milling is 1:5, the diameter of the steel ball is 10 mm, the ball milling time is 4 h, and the ball milling rotation mode is forward rotation, to obtain raw material powder;

[0133] Step 2: Hot pressing and sintering:

[0134] The raw material powder obtained by ball milling in step 1 is placed in a mold for hot pressing sintering. The sintering temperature is 1000° C., the pressure is 60 MPa, and the sintering time is 6 h. After removing the mold, an O-containing titanium-based composite material is obtained.

[0135] Fig.12 The metallographic micrograph of the titanium-based composite material containing O prepared in this comparative example is shown in FIG. Fig.12 As shown, there is a large range of inhomogeneous structure in the metallographic structure.

Claims

1. A method for preparing a gap-reinforced titanium-based composite material with matching room temperature ductility and high temperature strength, characterized in that: The steps include: Step 1: Prepare raw material powder: Oxygen, nitrogen or carbon is used as interstitial element, TiB, La2O3 or Y2O3 is used as reinforcing phase; interstitial element additive powder, reinforcing phase reactant powder and titanium alloy matrix powder are weighed according to the designed interstitial element content and reinforcing phase content, and the interstitial element additive powder, reinforcing phase reactant powder and titanium alloy matrix powder are mixed and ball-milled to obtain raw material powder; Step 2: Preparation of interstitial element reinforced titanium-based composite powder: The raw material powder obtained by ball milling is subjected to hot pressing sintering or hot isostatic pressing to obtain a raw material rod, and then powdered by plasma rotating electrode atomization to obtain a titanium-based composite powder reinforced with interstitial elements; Step 3: Preparation of gap-reinforced titanium-based composite materials: The obtained interstitial element reinforced titanium-based composite powder is subjected to hot pressing sintering or hot isostatic pressing to obtain an interstitial reinforced titanium-based composite material.

2. The method for preparing a gap-reinforced titanium-based composite material with matching room temperature ductility and high temperature strength according to claim 1, characterized in that: Step 1: The particle size of the interstitial element additive powder is 50 nm, 100 nm, 1 μm, 2 μm, 3 μm or 5 μm. When the interstitial element is oxygen, the corresponding additive powder is TiO2 powder. When the interstitial element is nitrogen, the corresponding additive powder is TiN powder. When the interstitial element is carbon, the corresponding additive powder is graphite powder. The particle size of the reinforcing phase reactant powder is 50nm, 100nm, 1μm, 2μm, 3μm or 5μm. When the reinforcing phase is TiB, the reinforcing phase reactant powder is TiB2, ZrB2 or BN powder. When the reinforcing phase is La2O3, the reinforcing phase reactant powder is La2O3 or LaB6 powder. When the reinforcing phase is Y2O3, the reinforcing phase reactant powder is Y2O3 powder. The particle size distribution range of the titanium alloy matrix powder is 1-75μm, 1-53μm, 75-150μm, 53-180μm, 150-250μm, 1-150μm, 1-180μm or 1-250μm, and the titanium alloy matrix powder is Ti, TC4, TA15, Ti65, Ti60, Ti55 or TC11 powder.

3. A method for preparing a gap-reinforced titanium-based composite material with matching room temperature ductility and high temperature strength according to claim 1 or 2, characterized in that: In step 1, the rotation speed of the ball mill is 100-400 r / min, the mass ratio of the material to the steel ball during ball milling is 1:1-7, the diameter of the steel ball is 6 mm or 10 mm, the ball milling time is 2-8 h, and the ball mill rotation mode is forward, reverse or alternating forward and reverse.

4. The method for preparing a gap-reinforced titanium-based composite material with matching room temperature ductility and high temperature strength according to claim 3, characterized in that: The hot pressing sintering in step 2 is to place the raw material powder obtained in step 1 in a mold for sintering, the sintering temperature is 1200-1400°C, the pressure is 10-40MPa, and the sintering time is 1.5-2.5h; the hot isostatic pressing is to place the raw material powder obtained in step 1 in a titanium sheath, the sintering temperature is 1200-1400°C, the pressure is 100-200MPa, and the sintering time is 1.5-2.5h.

5. The method for preparing a gap-reinforced titanium-based composite material with matching room temperature ductility and high temperature strength according to claim 4, characterized in that: The processing diameter of the raw material bar in step 2 is 25mm, 50mm or 75mm.

6. The method for preparing a gap-reinforced titanium-based composite material with matching room temperature ductility and high temperature strength according to claim 5, characterized in that: In step 2, the feed speed of the plasma rotating electrode atomization powder making is 0.5-3 mm / s, the arc current is 1500-3000 A, and the rod rotation speed is 10000-30000 r / min.

7. The method for preparing a gap-reinforced titanium-based composite material with matching room temperature ductility and high temperature strength according to claim 6, characterized in that: The particle size distribution range of the interstitial element reinforced titanium-based composite powder obtained by atomization powder making in step 2 is 1-75 μm, 1-53 μm, 75-150 μm, 53-180 μm, 150-250 μm, 1-150 μm, 1-180 μm or 1-250 μm.

8. The method for preparing a gap-reinforced titanium-based composite material with matching room temperature ductility and high temperature strength according to claim 6, characterized in that: The hot pressing sintering in step three is to place the interstitial element reinforced titanium-based composite powder obtained in step two in a mold for sintering, the sintering temperature is 950-1100°C, the pressure is 20-80MPa, and the sintering time is 1-10h; the hot isostatic pressing is to place the interstitial element reinforced titanium-based composite powder obtained in step two in a titanium sheath, the sintering temperature is 900-1100°C, the pressure is 100-200MPa, and the sintering time is 1-10h.

9. A gap-reinforced titanium-based composite material having matched room temperature strength and plasticity with high temperature strength prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The interstitial element content is 0.01-1 wt%, and the reinforcement phase content is 0.1-6 vol.%.

10. The gap-reinforced titanium-based composite material with matching room temperature strength and plasticity with high temperature strength according to claim 9, characterized in that: When the interstitial element is oxygen, the content of oxygen is 0.15-0.25 wt %; when the interstitial element is nitrogen, the content of nitrogen is 0.075-0.15 wt %; when the interstitial element is carbon, the content of carbon is 0.03-0.2 wt %.

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