Tungsten mesh reinforced high-temperature titanium alloy part with mechanical property capable of being regulated and controlled in partition mode and preparation method thereof

Abstract

The invention discloses a tungsten mesh reinforced high-temperature titanium alloy part with the mechanical property capable of being regulated and controlled in a partitioned mode and a preparation method of the tungsten mesh reinforced high-temperature titanium alloy part, and belongs to the technical field of metal-based composite materials. The method solves the problems that the performance of a traditional part cannot be regulated and controlled in a partitioned mode, the adaptability of an interface modification technology and multiple working conditions is insufficient, and stress field distribution is mismatched. A high-bearing area is determined through topological optimization, a tungsten mesh with a silicon carbide coating is used as a reinforcement body in the area, and a reinforcement layer is formed at an interface of silicon carbide and a matrix; a coating-free tungsten mesh reinforcement is arranged in a plastic deformation area, and stress redistribution is achieved by regulating and controlling the diameter of a tungsten filament and the density of meshes. And a vacuum hot pressing sintering-superplastic forming process is adopted to realize multi-scale interface combination of the titanium alloy matrix and the tungsten mesh. The tensile strength of the tungsten mesh reinforced high-temperature titanium alloy part in a reinforced area is improved, the ductility of a plastic deformation area is improved, the interfacial shear strength is increased, different mechanical properties in different areas are achieved, and the method is suitable for directional performance enhancement of complex components in the aerospace field.

Description

Technical Field

[0001] The present invention belongs to the field of metal matrix composites, and particularly relates to a tungsten mesh reinforced high-temperature titanium alloy part with controllable mechanical properties in different zones and a preparation method thereof. Background Art

[0002] Tungsten mesh reinforced high-temperature titanium alloy composites have important application values in key components such as aero-engine blades and spacecraft load-bearing frames due to their high specific strength, excellent high-temperature properties, and designability. Traditional preparation methods mainly improve the overall performance of high-temperature titanium alloys by uniformly arranging tungsten mesh reinforcements. However, with the development of material components towards lightweight and multi-functional directions, the existing preparation methods of tungsten mesh reinforced high-temperature titanium alloy composites have revealed significant defects: (1) Traditional processes use a single type (such as all-coated or all-naked wires) of tungsten mesh with uniform layering as the reinforcement, resulting in similar mechanical properties in different regions of the composite. However, during the service of actual components, the stress states borne by different parts are significantly different (for example, the blade root requires high strength and fatigue resistance, and the leading edge requires high plasticity and impact resistance). The existing technology cannot achieve the gradient performance matching of "directional strengthening in high-strength zones and local toughening in high-plasticity zones". For example, when using tungsten mesh reinforced with all silicon carbide coatings, the elongation of the composite is generally lower than 7%, which is difficult to meet the engineering requirements of the plastic deformation zone ≥ 15%; while the interfacial shear strength of the all-naked tungsten mesh reinforcement system is only 120 - 150 MPa, which cannot meet the strength requirements of the main load-bearing zone ≥ 200 MPa. (2) The adaptability of the interface modification process to multiple working conditions is insufficient: Existing interface strengthening mostly uses global consistency treatment (such as spraying a silicon carbide coating on the tungsten mesh as a whole and then using it as a reinforcement for strengthening). Although the interface strength can be improved through TiC / Ti5Si3 strengthening phases, the brittle characteristics of the silicon carbide coating will significantly reduce the toughness of all interfaces, resulting in brittle fractures prone to occur in stress concentration regions. Some studies have shown that the crack propagation rate of the tungsten mesh / high-temperature titanium alloy interface with a silicon carbide coating is 2.3 - 3.5 times that of the pure tungsten mesh interface, seriously restricting the reliability of the material under dynamic loads. (3) Mismatch in stress field distribution: The laminated structures in traditional composites mostly use tungsten meshes with equal mesh density (usually 30 - 40 meshes) and equal wire diameter (0.2 mm) for stacking, resulting in a step-by-step attenuation of stress along the thickness direction. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a tungsten mesh reinforced high-temperature titanium alloy part with controllable mechanical properties in different zones and a preparation method thereof.

[0004] In order to solve the above technical problems, the present invention is realized through the following technical solutions:

[0005] One of the objectives of the present invention is to provide a preparation method for a tungsten mesh with a coating, and the method includes:

[0006] Step 1: Clean the tungsten mesh with ethanol, then dry it. Prepare an alkaline cleaning solution and perform alkaline cleaning on the dried tungsten mesh. After alkaline cleaning, dry the tungsten mesh for standby.

[0007] Step 2: Take the dried tungsten mesh for standby and perform sandblasting or machining.

[0008] Step 3: Preheat the tungsten mesh processed in Step 2. After preheating, perform plasma spraying on the tungsten mesh with a composite powder to obtain a tungsten mesh with a coating.

[0009] Further defined, in Step 1, the alkaline cleaning solution is a 50wt% NaOH solution, the alkaline cleaning temperature is 80 - 100°C, the alkaline cleaning time is 10 - 14h, and the alkaline cleaning process uses water bath heating.

[0010] Further defined, in Step 1, the tungsten mesh is made by a weaving method, and all nodes have solder joints.

[0011] Further defined, in Step 3, the composite powder is a powder composed of zirconia and silicon carbide in a volume ratio of 3:7.

[0012] Further defined, the plasma spraying parameters in Step 3 are: spraying current 700 - 750A, spraying voltage 65 - 75V, spraying distance 100 - 140mm, the plasma gas is hydrogen, the hydrogen flow rate is 10 - 20L / min, the powder feeding gas is argon, the powder feeding flow rate is 5 - 10L / min, and the coating thickness is 50 - 200μm.

[0013] The second object of the present invention is to provide a tungsten mesh with a coating prepared by the above method.

[0014] The third object of the present invention is to provide a method for preparing a tungsten mesh-reinforced high-temperature titanium alloy part with controllable mechanical properties in different zones by using the above tungsten mesh coating. The method includes:

[0015] Step 1: Determine the size of the forming part to be formed, and determine the large deformation area and non-large deformation area during the forming process through topology optimization software.

[0016] Step 2: Grind the plate to be flat, remove the surface oil stain, remove the impurities on the plate by pickling, and wash and dry it with ethanol for standby.

[0017] Step 3: Take a tungsten mesh with a coating having the same shape as the non-large deformation area, and take an uncoated tungsten mesh, cut it into the same shape as the large deformation area. After cutting, perform a cleaning treatment. After the cleaning treatment, place the uncoated tungsten mesh in the large deformation area, and place the tungsten mesh with a coating in the non-large deformation area. The uncoated tungsten mesh and the tungsten mesh with a coating form a composite tungsten mesh. Subsequently, take two plates prepared in Step 2, spray a release agent on each of the two plates respectively, and then place the plates on the upper side and the lower side of the composite tungsten mesh respectively, and tie and fix them with iron wires to obtain a combined plate.

[0018] Step 4: Spray a release agent on the part of the vacuum hot pressing and sintering die that is in direct contact with the lower surface of the composite plate, and blow it dry after spraying.

[0019] Step 5: Place the composite plate sprayed with the release agent in the vacuum hot pressing and sintering die for vacuum hot pressing and sintering. After sintering, cool down and take out the parts.

[0020] Step 6: Grind the surface of the composite plate obtained by vacuum hot pressing and sintering to obtain a high-temperature titanium alloy composite plate reinforced with a composite tungsten mesh.

[0021] Step 7: Set the furnace temperature of the superplastic forming equipment. After reaching the temperature, place the composite plate obtained in Step 6 into the die.

[0022] Step 8: Close the die, apply pressure, start ventilating. After maintaining the pressure for a period of time, close the ventilation valve, stop heating, cool down and take out the parts.

[0023] Further defined, the plate material in Step 2 is a high-temperature titanium alloy; the liquid used in the pickling process is a mixed liquid composed of hydrofluoric acid, nitric acid and water in a volume ratio of 1:3:6, and the pickling time is 1 - 4 min.

[0024] Even further defined, the concentrations of both hydrofluoric acid and nitric acid are 90%.

[0025] Further defined, the uncoated tungsten mesh in Step 3 is made by a weaving method, and the nodes are all with solder joints.

[0026] Further defined, the cleaning process of the uncoated tungsten mesh in Step 3 is: wash the uncoated tungsten mesh with ethanol and blow it dry, prepare an alkaline cleaning solution and perform alkaline cleaning on the blown-dry uncoated tungsten mesh, and blow it dry after alkaline cleaning.

[0027] Even further defined, the alkaline cleaning solution is a 50wt% NaOH solution, the alkaline cleaning temperature is 80 - 100 °C, the alkaline cleaning time is 10 - 14 h, and the alkaline cleaning process uses water bath heating.

[0028] Further defined, the vacuum degree of the vacuum hot pressing and sintering in Step 5 is not less than 1×10 -2 Pa, the hot pressing and sintering pressure is 10 - 30 MPa, and the temperature is 860 - 960 °C.

[0029] The fourth object of the present invention is to provide a tungsten mesh-reinforced high-temperature titanium alloy part with mechanically controllable zoning prepared by the above method.

[0030] The beneficial effects of the present invention are:

[0031] Different from traditional composites with uniform enhancement across the board, the present invention can endow composites with different mechanical properties in different parts, while also taking into account high strength and high plasticity. It can not only better meet the complex performance requirements of aerospace components, but also satisfy the high-demand usage environments of complex components.

[0032] Compared with the prior art, the present invention also has the following advantages:

[0033] (1) The present invention enables the mechanical properties of the tungsten mesh-reinforced high-temperature titanium alloy composite to be distributed as needed. That is, according to the actual requirements of different parts, the composite can have corresponding mechanical properties, so that different parts of the entire composite have different mechanical properties. The present invention drives the partition layout of the reinforcement through topology optimization. In high-load areas (such as composites used for blade roots), tungsten mesh reinforcements with SiC coatings are used. In-situ reactions between the coating and the high-temperature titanium alloy matrix generate TiC / Ti5Si3 strengthening phases, increasing the tensile strength and interfacial shear strength in high-load areas. In areas where plastic deformation is required (such as composites used for component bending areas), uncoated tungsten meshes are used for reinforcement. By adjusting the mesh density (20 - 50 meshes) and wire diameter (0.1 - 0.3 mm), the stress distribution is optimized, increasing the elongation rate and achieving a performance match of "controllable strength and toughness, distributed as needed".

[0034] (2) Enhancement of the interfacial properties between the reinforcement and the high-temperature titanium alloy matrix: The reinforcement used in non-large-deformation areas of the present invention is a tungsten mesh with a coating. A 50 - 200 μm silicon carbide layer is formed on the surface of the tungsten mesh by plasma spraying. During high-temperature diffusion, the SiC coating reacts with the high-temperature titanium alloy matrix to form an interfacial layer in a gradient form (the outer layer near the high-temperature titanium alloy region has a composition of TiC, and the inner layer near the reinforcement region has a composition of Ti5Si3). This gradient interfacial structure not only improves the interfacial bonding strength between the tungsten mesh with SiC coating and the titanium alloy matrix, but also alleviates the risk of brittle fracture. At the same time, in large-deformation areas, the interface between the uncoated tungsten mesh and the titanium alloy matrix is flexible, being a flexible interface. This is because the uncoated tungsten mesh directly diffuses and bonds with the high-temperature titanium alloy matrix, avoiding the formation of brittle phases and greatly enhancing the interfacial toughness in this area (plastic deformation area). In addition, the gradient interfacial layer (the outer layer near the high-temperature titanium alloy region has a composition of TiC, and the inner layer near the reinforcement region has a composition of Ti5Si3) formed at the interface between the tungsten mesh with SiC coating and the high-temperature titanium alloy matrix in the present invention can also reduce the compositional abrupt change at the interface, reducing the stress concentration caused by lattice mismatch and resulting in a higher interfacial bonding strength.

[0035] (3) The present invention realizes the stress synergy optimization of the composite material: a tungsten mesh with a low mesh number (20 - 30 meshes) and a thick wire diameter (0.3 mm) is used in the high-stress area to reduce the stress concentration factor; a tungsten mesh with a high mesh number (40 - 50 meshes) and a thin wire diameter (0.1 mm) is used in the low-stress area to reduce the matrix flow resistance and control the porosity. This is because when the mesh density in the high-stress area is lower than 20 meshes, the local stress concentration factor is too high; while using a high-mesh number mesh (>50 meshes) in the low-stress area will cause the flow of the high-temperature titanium alloy matrix to be blocked, resulting in an increase in porosity during vacuum hot pressing forming and a decrease in the density of the composite material. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of the reinforcement placement in Example 1. 1 is the flat plate for placing the reinforcement, 2 is the tungsten mesh without coating, and 3 is the tungsten mesh with a SiC coating;

[0037] Figure 2 It is the dimensional drawing and schematic diagram of the formed part in Example 1. (a) is the dimensional drawing of the formed part in the front view and top view directions, and (b) is the schematic diagram of the formed part;

[0038] Figure 3 It is the schematic diagram of the vacuum hot pressing sintering die in Step 5 of Example 1;

[0039] Figure 4 It is a photo of the formed part in Example 1;

[0040] Figure 5 It is a comparison diagram of the high-temperature mechanical properties at 600 °C of the specimens intercepted from the large-deformation area and non-large-deformation area of the Ti60 high-temperature titanium alloy plate and the composite plate;

[0041] Figure 6 It is a comparison diagram of the room-temperature mechanical properties of the Ti60 high-temperature titanium alloy plate and the Ti60 high-temperature titanium alloy composite plate reinforced with pure tungsten mesh;

[0042] Figure 7 It is a comparison diagram of the high-temperature mechanical properties of the Ti60 high-temperature titanium alloy plate and the Ti60 high-temperature titanium alloy composite plate reinforced with a tungsten mesh with a SiC coating. Detailed Embodiment

[0043] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following describes the detailed embodiment of the present invention in conjunction with the embodiments of the specification.

[0044] Many specific details are set forth in the following description to fully understand the present invention, but the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0045] Second, as used herein, "an embodiment" or "embodiments" refer to specific features, structures, or characteristics that may be included in at least one implementation of the present invention. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or alternative embodiment that is mutually exclusive with other embodiments.

[0046] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified. The materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in this field, and those skilled in the art can obtain them through commercial channels without special instructions.

[0047] Example 1

[0048] Step 1: Determine the size of the forming part to be formed. The specific dimensions are shown in Figure 2 (a), with the dimension unit being mm. Determine the large deformation region, non-large deformation region, high load-bearing region, low load-bearing region, high stress region, low stress region, plastic deformation region, and non-plastic deformation region during the forming process through topology optimization software;

[0049] Among them, they are divided into a large deformation region and a non-large deformation region according to the degree of deformation; into a high load-bearing region and a low load-bearing region according to the level of load to be borne; into a high stress region and a low stress region according to the magnitude of the stress borne; and into a plastic deformation region and a non-plastic deformation region according to whether plastic deformation is required;

[0050] The large deformation region, low load-bearing region, low stress region, and plastic deformation region are in the same position, and the four are in a corresponding relationship; the non-large deformation region, high load-bearing region, high stress region, and non-plastic deformation region are in the same position, and the four are in a corresponding relationship;

[0051] Step 2: According to the size of the formed part determined in Step 1, grind the Ti60 high-temperature titanium alloy plate with a size of 60 mm × 60 mm and a thickness of 2 mm until it is flat, and remove the surface oil stain. Ensure that the plate is smooth and has no obvious deformation during the grinding stage. After grinding, pickle the plate with a combined liquid of hydrofluoric acid: nitric acid: water (volume ratio) of 1:3:6 for 2 minutes to remove impurities, and then clean it with anhydrous ethanol, dry it, and set it aside for use;

[0052] Step 3: Take a tungsten mesh with a SiC coating (mesh number 30, wire diameter 0.3 mm) whose shape is the same as that of the non-large deformation area. Additionally, take an uncoated tungsten mesh that is woven and has solder joints at the nodes, and cut it into the same shape as the large deformation area (mesh number 50, wire diameter 0.1 mm). Wash the cut uncoated tungsten mesh with absolute ethanol and dry it. Prepare a NaOH solution with a concentration of 50 wt%, and perform alkali washing on the dried uncoated tungsten mesh. The alkali washing is carried out by water bath heating, with an alkali washing temperature of 100 °C and a time of 12 h. After the alkali washing, dry it with absolute ethanol. As Figure 1 shown, place the uncoated tungsten mesh in the large deformation area, and place the tungsten mesh with a SiC coating in the non-large deformation area. The tungsten mesh with a SiC coating and the uncoated tungsten mesh together form a composite tungsten mesh. Subsequently, take two pieces of the prepared Ti60 high-temperature titanium alloy plates from Step 2, cut the two plates into the shape of the composite tungsten mesh, spray the release agent boron nitride on only one side of each of the two Ti60 high-temperature titanium alloy plates, without spraying both sides. After the boron nitride spraying is completed, dry it. Place the Ti60 high-temperature titanium alloy plates on the upper and lower sides of the composite tungsten mesh respectively. Among them, the side of the bottom Ti60 high-temperature titanium alloy plate with boron nitride sprayed faces down, and the side of the top Ti60 high-temperature titanium alloy plate with boron nitride sprayed faces up, that is, the positions where the two plates are sprayed with the release agent are on the other side of the contact surface in contact with the composite tungsten mesh. To keep the positions of the Ti60 high-temperature titanium alloy plates and the composite tungsten mesh fixed during the vacuum hot pressing sintering process, tie the stacked plates and the reinforcement with iron wire with a diameter of 0.1 mm to obtain a combined plate;

[0053] Among them, the preparation method of the tungsten mesh with a SiC coating is as follows: Take a woven tungsten mesh with solder joints at the nodes, wash it with absolute ethanol and dry it. Prepare a NaOH solution with a concentration of 50 wt%, and perform alkali washing on the dried tungsten mesh. The alkali washing is carried out by water bath heating, with an alkali washing temperature of 100 °C and a time of 12 h. After the alkali washing, dry it with absolute ethanol. Subsequently, place the tungsten mesh on a flat plate and increase its surface roughness by sandblasting. After treating one side, turn the tungsten mesh over and treat it again to ensure that the surface of the tungsten wire of the tungsten mesh is completely treated and has a certain roughness. Preheat the tungsten mesh (preheating temperature is 200 °C) to reduce thermal stress. Use a composite powder composed of zirconia and silicon carbide in a volume ratio of 3:7 for plasma spraying. The plasma spraying process parameters are: spraying current 700 - 750 A, spraying voltage 65 - 75 V, spraying distance 120 mm, plasma gas is hydrogen, hydrogen flow rate 15 L / min, powder feeding gas is argon, powder feeding flow rate 7 L / min. After spraying, cool it naturally,

[0054] prevent the coating from cracking. After cooling to room temperature, observe whether the surface of the coating is uniform and crack-free to form a SiC coating with a thickness of about 120 μm, and obtain a tungsten mesh with a SiC coating;

[0055] Step 4: Spray the parting agent boron nitride on the part of the vacuum hot pressing and sintering die that is in direct contact with the lower surface of the composite sheet. After spraying, dry it with a hair dryer.

[0056] Step 5: Place the composite sheet sprayed with boron nitride into the vacuum hot pressing and sintering die, and then put the composite sheet together with the die into a vacuum hot pressing furnace for vacuum hot pressing and sintering: evacuate the vacuum hot pressing furnace to 1×10 -2 Pa, heat up to 900 °C, apply a pressure of 20 MPa, maintain for 2 h, then release the pressure, stop heating, start cooling, and take out the workpiece after cooling to room temperature.

[0057] Step 6: Grind the composite sheet after vacuum hot pressing and sintering to remove the surface interference layer to obtain a composite plate.

[0058] Step 7: Set the furnace temperature of the superplastic forming equipment to the forming temperature of the Ti60 high-temperature titanium alloy sheet, which is 900 °C. After reaching the temperature, place the composite plate obtained in Step 6 into the die.

[0059] Step 8: When placing the composite plate into the die in Step 7, since the equipment is opened, the temperature will drop, so it is necessary to heat up again. After reaching the forming temperature, keep it warm for 10 min, close the die (just make the die and the composite plate compacted), apply a pressure of 30 MPa, start ventilation, and apply pressure according to the gas pressure loading curve of the superplastic forming finite element simulation. Keep the pressure for 15 min, close the ventilation valve, stop heating. After the furnace temperature drops to room temperature, open the die and take out the workpiece to obtain a formed part.

[0060] In this embodiment, the placement position of the reinforcement is as Figure 1 shown. Since a large deformation needs to occur in the fillet area during the forming process, in order to improve plasticity, the tungsten mesh 2 without sprayed coating is placed, and the tungsten mesh 3 with SiC coating is placed in the non-large deformation area. 1 is the flat plate used to place the reinforcement, and the function of this flat plate is only to let the reinforcement be placed well on it and does not participate in the forming process.

[0061] The cross-sectional photo of the box-shaped part formed in this embodiment is as Figure 4 shown. The longer sheet-like extension parts on both sides of the box-shaped part are the process section parts. The shape of the complete box-shaped part after cutting off the process section parts is as Figure 2 (b) shown.

[0062] Figure 5It is a comparison chart of the high-temperature mechanical properties at 600 °C of specimens intercepted from the large-deformation area and non-large-deformation area of Ti60 high-temperature titanium alloy plates and composite plates. It can be seen that the use of tungsten mesh without coating significantly reduces the flow stress in the large-deformation area and enhances the plasticity in the large-deformation area. The use of tungsten mesh sprayed with silicon carbide significantly improves the strength in the non-large-deformation area, indicating that the present embodiment successfully realizes the directional control of the strength and plasticity of the composite plate, breaking through the limitation of uniform enhancement in all directions of traditional composite plates.

[0063] Comparative Example 1

[0064] Step 1: Cut the Ti60 high-temperature titanium alloy plate into 50 mm × 50 mm and polish it flat to remove the surface oil stain. During the polishing stage of the plate, it is necessary to ensure that the Ti60 high-temperature titanium alloy is smooth and has no obvious deformation. After polishing, pickle the alloy plate with a liquid with a composition of hydrofluoric acid: nitric acid: water (volume ratio) of 1:3:6 for 2 min to remove impurities. After that, clean it with anhydrous ethanol, dry it, and set it aside for later use.

[0065] Step 2: Cut the tungsten mesh (100 mesh) into 50 mm × 50 mm in size, and clean the surface oil stain and other impurities with alcohol. The tungsten mesh used is woven, and the nodes are with solder joints. The tungsten mesh material is pure tungsten. Prepare a NaOH solution with a concentration of 50 wt%. Use the water bath method to heat the prepared NaOH solution to 100 °C, put the tungsten mesh in, ensure that the tungsten mesh is suspended in the NaOH solution, and all its planes are in contact with the NaOH solution. The cleaning time is 12 h. After cleaning, clean the tungsten mesh with alcohol, dry it, and set it aside for later use.

[0066] Step 3: Take two pieces of Ti60 high-temperature titanium alloy plates prepared in Step 1 and one piece of tungsten mesh prepared in Step 2, and stack them in order from bottom to top as Ti60 high-temperature titanium alloy plate, tungsten mesh, and Ti60 high-temperature titanium alloy plate. To prevent the positions of the plate and the tungsten mesh from changing during the vacuum hot pressing process, tie the stacked plate and tungsten mesh with iron wire with a diameter of 0.1 mm to obtain a composite plate with a combination form of Ti60 high-temperature titanium alloy / tungsten mesh / Ti60 high-temperature titanium alloy.

[0067] Step 4: Spray the release agent boron nitride on the upper surface of the composite plate and the lower surface in direct contact with the vacuum hot pressing mold. After spraying, dry it for later use, and spray the release agent boron nitride on the part of the vacuum hot pressing mold in direct contact with the lower surface of the composite plate.

[0068] Step 5: Place the vacuum hot pressing mold in the vacuum hot pressing equipment, and place the composite plate sprayed in Step 4 in the vacuum hot pressing sintering mold. Vacuumize the vacuum hot pressing equipment to 1×10 -2Set the heating temperature to 900 °C, the holding time to 120 min, the pressure to 7500 Kg (30 MPa), and the heat preservation and pressure holding time to 1 h. After setting the parameters, perform vacuum hot pressing and sintering. After sintering, cool down to room temperature and take out the parts.

[0069] Step 6: Grind the combined plate after hot pressing and sintering to remove the surface interference layer, and obtain a tungsten mesh reinforced Ti60 high-temperature titanium alloy composite plate.

[0070] Comparative Example 2

[0071] The difference between this comparative example and Comparative Example 1 is that the mesh number of the tungsten mesh is 10 meshes, and the other process steps and parameter settings are the same as those in Example 1.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Comparative Example 1 is that the mesh number of the tungsten mesh is 50 meshes, and the other process steps and parameter settings are the same as those in Example 1.

[0074] Comparative Example 4

[0075] The difference between this comparative example and Comparative Example 1 is that the mesh number of the tungsten mesh is 200 meshes, and the other process steps and parameter settings are the same as those in Example 1.

[0076] Comparative Example 5

[0077] Step 1: Grind a Ti60 high-temperature titanium alloy plate with dimensions of 50 mm × 50 mm and a thickness of 2 mm to make it flat and remove the surface oil stain. Ensure that the plate is smooth and has no obvious deformation during the grinding stage. After grinding, pickle the plate with a combined liquid of hydrofluoric acid: nitric acid: water (volume ratio) of 1:3:6 for 2 min to remove impurities. After that, clean it with anhydrous ethanol, dry it, and set it aside for use.

[0078] Step 2: Take a pure tungsten mesh (50 mm × 50 mm) woven and with solder joints at the nodes, wash it with anhydrous ethanol, dry it, prepare a NaOH solution with a concentration of 50 wt%, perform alkali washing on the dried tungsten mesh, use water bath heating for alkali washing, the alkali washing temperature is 100 °C, and the time is 12 h. After alkali washing, dry it with anhydrous ethanol and set it aside for use.

[0079] Step 3: Place the tungsten mesh on a flat plate, increase its surface roughness by sandblasting or machining. After processing one side, turn over the tungsten mesh and process it again to ensure that the tungsten wire surface of the tungsten mesh is completely processed and has a certain roughness.

[0080] Step 4: Preheat the tungsten mesh (preheating temperature is 200 °C) to reduce thermal stress, and perform plasma spraying using a composite powder composed of zirconia and silicon carbide in a volume ratio of 3:7. The plasma spraying process parameters are: spraying current 700 - 750 A, spraying voltage 65 - 75 V, spraying distance 120 mm, plasma gas is hydrogen, hydrogen flow rate 15 L / min, powder feeding gas is argon, powder feeding flow rate 7 L / min. After spraying, cool naturally to prevent the coating from cracking. After cooling to room temperature, observe whether the surface of the coating is uniform and crack-free, and form a SiC coating on the surface of the tungsten mesh;

[0081] Step 5: Take two pieces of Ti60 high-temperature titanium alloy plates prepared in Step 1 and one piece of tungsten mesh sprayed with SiC coating in Step 4, and stack them in order from bottom to top as Ti60 high-temperature titanium alloy plate, tungsten mesh with SiC coating, and Ti60 high-temperature titanium alloy plate. To prevent the position of the plate and the tungsten mesh from shifting during vacuum hot pressing, tie the stacked plates and the tungsten mesh with SiC coating together with a wire with a diameter of 0.1 mm to obtain a three-layer composite plate with the combination form of Ti60 high-temperature titanium alloy / tungsten mesh with SiC coating / Ti60 high-temperature titanium alloy;

[0082] Step 6: Spray the release agent boron nitride on the upper surface of the composite plate and the lower surface in direct contact with the vacuum hot pressing mold, and spray the release agent boron nitride on the part of the vacuum hot pressing mold in direct contact with the lower surface of the composite plate, and dry it with a hair dryer for standby;

[0083] Step 7: Fix the composite plate sprayed with boron nitride with a wire and place it in the vacuum hot pressing mold, then put it into the vacuum hot pressing furnace. Vacuum the vacuum hot pressing equipment to 1×10 -2 Pa, set the heating temperature to 900 °C, heating time to 120 min, pressure to 7500 Kg, and holding and pressing time to 2 h. After setting the parameters, perform vacuum hot pressing sintering. After sintering, cool down to room temperature and take out the parts;

[0084] Step 8: Grind the composite plate after vacuum hot pressing sintering to remove the surface interference layer, and obtain a tungsten mesh-reinforced Ti60 high-temperature titanium alloy composite plate with a SiC coating.

[0085] The room temperature mechanical properties of the Ti60 high-temperature titanium alloy plate and the composite plates of Comparative Examples 1 - 4 are as Figure 6 shown. It can be seen that its room temperature plasticity has been improved, the deformation resistance has decreased, which is beneficial to large plastic deformation; The high-temperature mechanical properties of the Ti60 high-temperature titanium alloy plate and the composite plate of Comparative Example 5 are as Figure 7 shown. To ensure the accuracy of the data, the composite plate was tested three times. It can be seen that the mechanical properties of the composite plate of Comparative Example 5 have been greatly improved.

[0086] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention should cover within the protection scope of the present invention by making equivalent substitutions or changes according to the technical solution and inventive concept of the present invention.

Claims

1. A preparation method of a tungsten mesh with a coating, characterized in that, Including: Step 1: Clean the tungsten mesh with ethanol, then blow it dry. Prepare an alkaline cleaning solution and perform alkaline cleaning on the dried tungsten mesh. After alkaline cleaning, blow the tungsten mesh dry and set it aside for later use. Step 2: Take the tungsten mesh set aside and dried, and perform sandblasting or machining on it. Step 3: Preheat the tungsten mesh processed in Step 2. After preheating, perform plasma spraying on the tungsten mesh with a composite powder to obtain a tungsten mesh with a coating.

2. The preparation method according to claim 1, wherein In Step 3, the composite powder is a powder composed of zirconia and silicon carbide in a volume ratio of 3:

7.

3. The preparation method according to claim 1, wherein, The plasma spraying parameters in Step 3 are as follows: spraying current 700 - 750 A, spraying voltage 65 - 75 V, spraying distance 100 - 140 mm, the plasma gas is hydrogen, hydrogen flow rate 10 - 20 L / min, the powder feeding gas is argon, powder feeding flow rate 5 - 10 L / min, and the coating thickness is 50 - 200 μm.

4. A tungsten mesh with a coating, characterized in that, Prepared by the method according to any one of claims 1 - 3.

5. A method for preparing a tungsten mesh-reinforced high-temperature titanium alloy part with controllable mechanical properties in different zones by using the coated tungsten mesh according to claim 4, characterized in that, This method includes: Step 1: Determine the size of the forming part to be formed, and determine the large deformation area and non-large deformation area during the forming process through topology optimization software. Step 2: Grind the sheet to be flat, remove the surface oil stain, remove impurities on the sheet by pickling, wash it with ethanol, and blow it dry for later use. Step 3: Take a coated tungsten mesh with the same shape as the non-large deformation area, and take an uncoated tungsten mesh, cut it into the same shape as the large deformation area. After cutting, perform a cleaning treatment. After the cleaning treatment, place the uncoated tungsten mesh in the large deformation area, and place the coated tungsten mesh in the non-large deformation area. The uncoated tungsten mesh and the coated tungsten mesh form a composite tungsten mesh. Subsequently, take two sheets set aside in Step 2, spray a release agent on each of the two sheets respectively, then place the sheets on the upper and lower sides of the composite tungsten mesh respectively, and tie and fix them with iron wires to obtain a combined sheet. Step 4: Spray a release agent on the part of the vacuum hot pressing and sintering mold that is in direct contact with the lower surface of the combined sheet, and blow it dry after spraying. Step 5: Place the combined sheet sprayed with the release agent in the vacuum hot pressing and sintering mold for vacuum hot pressing and sintering. After sintering is completed, cool down and take out the part. Step 6: Perform surface grinding on the combined sheet obtained by vacuum hot pressing and sintering to obtain a high-temperature titanium alloy composite sheet reinforced with a composite tungsten mesh. Step 7: Set the furnace temperature of the superplastic forming equipment. After reaching the temperature, place the composite sheet obtained in Step 6 into the mold. Step 8: Close the mold, apply pressure, start ventilating. After maintaining the pressure for a period of time, close the ventilation valve, stop heating, cool down, and take out the part.

6. The preparation method according to claim 5, characterized in that, In Step 2, the material of the sheet is a high-temperature titanium alloy; the liquid used in the pickling process is a mixed liquid composed of hydrofluoric acid, nitric acid, and water in a volume ratio of 1:3:6, and the pickling time is 1 - 4 min.

7. The preparation method according to claim 5, wherein In Step 3, the uncoated tungsten mesh is made by weaving, and all the nodes have solder joints.

8. The preparation method according to claim 1, characterized in that The cleaning treatment process of the uncoated tungsten mesh in Step 3 is as follows: Wash the uncoated tungsten mesh with ethanol and blow it dry. Prepare an alkaline cleaning solution and perform alkaline cleaning on the dried uncoated tungsten mesh, and then blow it dry after alkaline cleaning.

9. The preparation method according to claim 1, characterized in that, In Step 5, the degree of vacuum in vacuum hot pressing sintering is not less than 1×10 -2 Pa, the hot pressing sintering pressure is 10 - 30 MPa, and the temperature is 860 - 960 °C.

10. A tungsten mesh-reinforced high-temperature titanium alloy part with zonally controllable mechanical properties, characterized in that, Prepared by the method according to any one of claims 5 - 9.

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