A cross-size TiB reinforced titanium matrix composite and its preparation method

Abstract

The present invention relates to the technical field of non-ferrous metal processing, and specifically relates to a cross-size TiB-reinforced titanium matrix composite and a preparation method thereof. The preparation method includes the steps of: preparing an ingot blank of a TiBw-reinforced titanium matrix composite, and processing the ingot blank of the TiBw-reinforced titanium matrix composite into a rod; preparing the rod into spherical powder of the TiBw-reinforced titanium matrix composite, and screening it into different particle sizes; ball-milling and mixing the spherical powder of the TiBw-reinforced titanium matrix composite and TiB2 powder, and then performing low-temperature pre-sintering at a set temperature to prepare a titanium matrix composite blank, and forming nano-scale TiB distributed dispersedly inside the powder; performing heat preservation treatment on the titanium matrix composite blank, and then performing hot deformation, so that the TiB2 phase in the titanium matrix composite blank completely reacts, and obtaining a micro-nano two-stage TiB-reinforced titanium matrix composite. The purpose of the cross-size TiB-reinforced titanium matrix composite and the preparation method thereof is to solve the problem of great difficulty in regulating the size and distribution of TiB in the TiB-reinforced titanium matrix composite.

Description

Technical Field

[0001] The present invention relates to the technical field of non-ferrous metal processing, and particularly relates to a cross-size TiB reinforced titanium matrix composite material and a preparation method thereof. Background Art

[0002] Discontinuous reinforced titanium matrix composites (DRTMCs) have excellent properties such as high specific strength, wear resistance and high temperature resistance, and have broad application prospects in the fields of aviation, aerospace, automotive industry, weaponry and the like.

[0003] At present, the main preparation methods of discontinuous reinforced titanium matrix composites are sintering method and melting and casting method. In the titanium matrix composites prepared by powder method, TiBw is distributed around titanium alloy particles, and there is no reinforcement phase distribution inside. If too much reinforcement phase is added, aggregation zones will be formed; in the titanium matrix composites prepared by melting and casting method, TiBw is mostly in strip shape and has large size. Due to the solidification characteristics of ingots, there is no effective regulation method yet. For example, patent (ZL200810136852.8) proposed a preparation method of a reticulated structure TiBw / Ti alloy matrix composite material, which can effectively regulate the distribution state of TiB and improve the room temperature plasticity of titanium matrix composites, and solves the bottleneck problem of large brittleness in the preparation of DRTMCS by powder metallurgy method; however, the reinforcement phase is distributed around powder particles, and there is almost no reinforcement phase in the matrix inside the reticulated structure, and it is not easy to regulate the size of TiB.

[0004] At present, when there is more TiBw in the titanium matrix composites prepared by powder method, aggregation is easy to form and the size regulation is difficult; in the titanium matrix composites prepared by melting and casting method, TiBw is mostly in strip shape and has large size. When the content is more, aggregation will also be formed, resulting in limited reinforcement effect; when preparing ingots by directly sintering titanium matrix composite powder, since the boride inside the titanium matrix composite powder is metastable, it will aggregate and grow after high-temperature sintering preparation, and it is difficult to retain a fine distribution state. Therefore, there is no good regulation method for the size and distribution of TiBw.

[0005] Therefore, the inventor provides a cross-size TiB reinforced titanium matrix composite material and a preparation method thereof. Summary of the Invention

[0006] (1) Technical Problems to be Solved

[0007] The embodiment of the present invention provides a cross-size TiB reinforced titanium matrix composite material and a preparation method thereof, which solve the technical problem of great difficulty in regulating the size and distribution of TiB in the TiB reinforced titanium matrix composite material.

[0008] (2) Technical Solutions

[0009] The first aspect of the present invention provides a preparation method of a cross-size TiB reinforced titanium matrix composite material, comprising the following steps:

[0010] Prepare an ingot of TiBw-reinforced titanium matrix composite, and process the ingot of TiBw-reinforced titanium matrix composite into a bar;

[0011] Prepare the bar into spherical powder of TiBw-reinforced titanium matrix composite, and screen out target spherical powder with a set particle size;

[0012] Perform ball milling and powder mixing on the target spherical powder and TiB2 powder, and then perform low-temperature pre-sintering at a set temperature to prepare a titanium matrix composite blank, in which nano-scale TiB is diffusely distributed inside the powder;

[0013] Perform heat preservation treatment on the titanium matrix composite blank, and then perform hot deformation, so that the TiB 2 phase completely reacts to obtain a micro-nano two-stage TiB-reinforced titanium matrix composite.

[0014] Furthermore, the volume fraction of TiBw in the ingot of TiBw-reinforced titanium matrix composite ranges from (0, 5%).

[0015] Furthermore, the volume fraction of TiB 2 powder added during the ball milling and powder mixing process ranges from (0, 5%).

[0016] Furthermore, the process of performing ball milling and powder mixing on the target spherical powder and TiB 2 powder, and then performing hot press pre-sintering at a set temperature to prepare a titanium matrix composite blank is specifically as follows:

[0017] Perform low-energy ball milling and powder mixing on the spherical powder of TiBw-reinforced titanium matrix composite and the TiB 2 powder, the ball-to-material ratio is (2-8):1, the rotation speed is 100-300 r / min, and the ball milling time is 5-15 h; the pressure for hot press pre-sintering is 10-30 MPa, and the heat preservation and pressure holding time is 0.5-3 h.

[0018] Furthermore, the size of the spherical powder of TiBw-reinforced titanium matrix composite is 50-150 μm, and the size of the TiB 2 powder is 1-5 μm.

[0019] Furthermore, the set temperature is 800-1200 °C.

[0020] Furthermore, the heat preservation time for heat preservation treatment is T = H×(1-2) min, where H is the thickness of the blank in mm.

[0021] Furthermore, the selected hot deformation is isothermal forging deformation, the temperature of isothermal forging deformation is 800-1200 °C, and the deformation rate is 0.0001 s -1 -0.1 s-1 。

[0022] The second aspect of the present invention provides a cross-size TiB-reinforced titanium matrix composite material, which is prepared by the above-mentioned preparation method.

[0023] Furthermore, the nano-scale TiB phase inside the matrix particles is dispersedly distributed, and the micro-scale TiB phase at the boundaries of the matrix particles is distributed in a network pattern.

[0024] (3) Beneficial effects

[0025] In summary, the present invention uses TiBw-reinforced titanium matrix composite powder and TiB 2 to prepare a titanium matrix composite ingot blank by powder mixing and sintering. Through low-temperature pre-sintering and hot deformation treatment, while ensuring complete reaction of TiB 2 a dispersed distribution of nano-scale TiB phase inside the matrix particles and a network distribution of micro-scale TiB phase at the boundaries of the matrix particles are achieved, forming a micro-nano cross-size TiB-reinforced titanium matrix composite. The size and distribution of TiBw inside and at the boundaries of the powder particles are effectively regulated, and the strength and plasticity of the material can be better improved. Description of the drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly introduced below. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 is a schematic flow chart of a preparation method of a cross-size TiB-reinforced titanium matrix composite material provided by an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of the microstructure photograph of a TiBw / TA15 composite material provided by Embodiment 1 of the present invention;

[0029] Figure 3 is a schematic diagram of the second-level TiBw morphology photograph of a TiBw / TA15 composite material provided by Embodiment 1 of the present invention. Detailed implementation manners

[0030] The following further describes in detail the implementation manners of the present invention in conjunction with the drawings and embodiments. The detailed description and drawings of the following embodiments are used to exemplarily illustrate the principle of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments, and covers any modifications, replacements, and improvements of parts, components, and connection methods without departing from the spirit of the present invention.

[0031] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0032] Figure 1 It is a schematic flow chart of a preparation method of a cross-size TiB reinforced titanium matrix composite provided by an embodiment of the present invention. As Figure 1 shown, the method may include the following steps:

[0033] S100. Prepare a TiBw reinforced titanium matrix composite ingot blank, and process the TiBw reinforced titanium matrix composite ingot blank into a rod;

[0034] S200. Prepare the rod into TiBw reinforced titanium matrix composite spherical powder, and screen out the target spherical powder with a set particle size;

[0035] S300. Ball mill and mix the target spherical powder and TiB 2 powder, and then perform low-temperature pre-sintering at a set temperature to prepare a titanium matrix composite blank, and nano-scale TiB is formed in a dispersed distribution inside the powder;

[0036] S400. Perform heat preservation treatment on the titanium matrix composite blank, and then perform hot deformation, so that the TiB 2 phase in the titanium matrix composite blank completely reacts to obtain a micro-nano two-stage TiB reinforced titanium matrix composite.

[0037] In the above embodiment, the reaction precipitation and growth of TiB are mainly affected by the heating temperature. Therefore, during the pre-sintering treatment, by reducing the sintering temperature, the growth degree of TiB inside the matrix particles is controlled, and nearly nano-scale TiB with a dispersed distribution is obtained. However, low-temperature sintering often causes problems such as incomplete reaction at the particle boundaries of TiB 2 and the formation of micro-pores. Therefore, after low-temperature sintering, hot deformation treatment is carried out. By continuous isothermal low-rate deformation, the reaction condition of TiB 2 at the matrix particle boundaries can be further improved, so that TiB 2 completely reacts to form TiB, and at the same time, the lower forging temperature reduces the influence on TiB inside the particles. Through hierarchical regulation, a titanium matrix composite with TiB distributed in different scales can be obtained.

[0038] As an optional embodiment, the volume fraction of TiBw in the TiBw reinforced titanium matrix composite ingot blank ranges from (0, 5%). Among them, the value range of the volume fraction is selected according to the size state of the cross-size TiB reinforced titanium matrix composite to be prepared.

[0039] As an optional embodiment, the TiB added during the ball milling and mixing process2 The value range of the volume fraction of the powder is (0, 5%). Among them, the value range of this volume fraction is selected according to the size state of the cross-size TiB-reinforced titanium matrix composite to be prepared.

[0040] As an alternative implementation, the target spherical powder and TiB 2 powders are ball-milled and mixed, and then hot-pressed and pre-sintered at a set temperature to prepare a titanium matrix composite blank. Specifically: The spherical powder of TiBw-reinforced titanium matrix composite and TiB 2 powders are ball-milled and mixed with low energy. The ball-to-material ratio is (2 - 8):1, the rotation speed is 100 - 300 r / min, and the ball-milling time is 5 - 15 h; The pressure of hot-press pre-sintering is 10 - 30 MPa, the heat preservation and pressure holding time is 0.5 - 3 h, and the set temperature is 800 - 1200 °C.

[0041] Specifically, for the specific process parameters of ball-milling and mixing and hot-press pre-sintering, they are conventional technical means in the art and can be selected according to the actual situation, so no further elaboration is given here.

[0042] As an alternative implementation, the size of the spherical powder of TiBw-reinforced titanium matrix composite is 50 - 150 μm, and the size of TiB 2 powder is 1 - 5 μm. Among them, the selected target spherical powder and TiB 2 powder are ball-milled and mixed to obtain a titanium matrix composite with different scale distributions of TiB.

[0043] As an alternative implementation, the heat preservation time for heat preservation treatment is T = H×(1 - 2) min, where H is the thickness of the blank in mm; The heat preservation temperature is 800 - 1200 °C.

[0044] Specifically, for the specific process parameters of heat preservation treatment before isothermal forging deformation, they are conventional technical means in the art and can be selected according to the actual situation, so no further elaboration is given here.

[0045] As an alternative implementation, the hot deformation is isothermal forging deformation. The temperature of isothermal forging deformation is 800 - 1200 °C, and the deformation rate is 0.0001 s -1 ~0.1 s -1 .

[0046] Specifically, for the specific process parameters of isothermal forging deformation, they are conventional technical means in the art and can be selected according to the actual situation, so no further elaboration is given here.

[0047] An embodiment of the present invention provides a cross-size TiB-reinforced titanium matrix composite. Prepared by the above preparation method, the nano-scale TiB phase inside the matrix particles is diffusely distributed, and the micron-scale TiB phase at the boundaries of the matrix particles is distributed in a network pattern.

[0048] Example 1

[0049] Prepare a 3.5vol% TiB / TA15 composite ingot by triple vacuum consumable electrode melting. Process the titanium matrix composite ingot into a Ф40×400mm bar, and prepare spherical powder of the titanium matrix composite in a plasma rotating electrode powder making device, where the electrode rotation speed is 28,000 r / min; the prepared spherical powder of 50 - 150μm and 1.5vol% TiB 2 powder are ball-milled and mixed. The size of the TiB 2 powder is 1 - 5μm, the ball-to-material ratio is 3:1, the rotation speed is 200 r / min, ball-mill for 5 - 8h, and carry out vacuum hot pressing sintering at 1200°C / 20MPa / 1.5h to prepare a titanium matrix composite ingot. Then place the ingot in a heating furnace at 1050°C for heat preservation for 30min, and carry out forging deformation at 0.001s -1 in an isothermal forging device at 1050°C to obtain a blank with an internal reinforcing phase distributed in two levels, namely large-size TiBw distributed around the matrix particles and small-size TiBw distributed inside the matrix particles, and no phenomenon of a large amount of TiBw aggregation appears. Its room temperature strength is 1082MPa, and the room temperature elongation rate reaches 5.9%; the tensile strength at 650°C is 540MPa, and the elongation rate reaches 11%.

[0050] Control test group

[0051] Ball-mill and mix the TA15 spherical powder and 5vol% TiB 2 powder. The size of the TA15 spherical powder is 50 - 150μm, and the size of the TiB 2 powder is 1 - 5μm, the ball-to-material ratio is 5:1, the rotation speed is 200 r / min, ball-mill for 5 - 8h, and carry out vacuum hot pressing sintering at 1300°C / 25MPa / 2h to prepare a titanium matrix composite ingot. The TiBw is distributed in a long network pattern at the boundaries of the matrix particles. Its room temperature strength is 1170MPa, and the room temperature elongation rate is only 2.8%; the tensile strength at 650°C is 507MPa, and the elongation rate is 11%.

[0052] It should be clear that the various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Also, for the sake of brevity, the detailed description of known methods and techniques is omitted here.

[0053] The above are only the embodiments of the present application and do not limit the present application. For those skilled in the art, various changes and modifications can be made to the present application without departing from the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A preparation method of a cross-size TiB-reinforced titanium matrix composite, characterized in that, the method comprises the following steps: Preparing a TiBw-reinforced titanium matrix composite ingot blank, and processing the TiBw-reinforced titanium matrix composite ingot blank into a bar; Preparing the bar into TiBw-reinforced titanium matrix composite spherical powder, and screening out target spherical powder with a set particle size; Mix the target spherical powder and TiB 2 powders by ball milling, and then perform low-temperature pre-sintering at a set temperature to prepare a titanium matrix composite blank, in which nano-scale TiB is diffusely distributed inside the powder; The titanium matrix composite blank is subjected to heat preservation treatment and then hot deformed so that the TiB in the titanium matrix composite blank 2 phase completely reacts to obtain a micro-nano two-stage TiB-reinforced titanium matrix composite; The size of the spherical powder of the TiBw-reinforced titanium matrix composite is 50-150 μm, and the size of the TiB 2 powder is 1-5 μm; The set temperature is 800-1200 °C, and the hot deformation is isothermal forging deformation, and the temperature of the isothermal forging deformation is 800-1200 °C.

2. The preparation method according to claim 1, characterized in that, the volume fraction of TiBw in the TiBw-reinforced titanium matrix composite ingot blank ranges from (0, 5%).

3. The preparation method according to claim 1, characterized in that, TiB added during the ball milling and powder mixing process 2 The volume fraction of the powder ranges from (0, 5%).

4. The preparation method according to claim 1, characterized in that, The target spherical powder and TiB 2 powders are ball-milled and mixed, and then hot-pressed and pre-sintered at a set temperature to prepare a titanium matrix composite blank, specifically: Mix the spherical TiBw-reinforced titanium matrix composite powder and the TiB 2 powder by low-energy ball milling with a ball-to-powder ratio of (2-8):1, a rotation speed of 100-300 r / min, and a ball milling time of 5-15 h; the pressure for hot press pre-sintering is 10-30 MPa, and the holding time under pressure is 0.5-3 h.

5. The preparation method according to claim 1, characterized in that, The heat preservation time of the heat preservation treatment is T = H×(1-2) min, where H is the thickness of the blank in mm.

6. The preparation method according to claim 1, characterized in that, The deformation rate is 0.0001 s -1 ~0.1 s -1 .

7. A cross-size TiB-reinforced titanium matrix composite, characterized in that, It is prepared by using the preparation method described in any one of claims 1-6.

8. The cross-size TiB-reinforced titanium matrix composite according to claim 7, characterized in that, The nano-scale TiB phase inside the matrix particles is diffusely distributed, and the micro-scale TiB phase at the boundaries of the matrix particles is distributed in a network pattern.

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