Preparation method of surface metallized ceramic particles and ceramic wear-resistant accessory

Abstract

The invention discloses a preparation method of surface metallized ceramic particles and a ceramic wear-resistant accessory, and mainly solves the technical problems of high cost, poor product performance, low yield and the like in the existing ceramic composite material preparation method. The preparation method of the surface metallized ceramic particles comprises the steps that wrapping alloy and ceramic particles with the volume ratio being (0.5-1.5): (8.5-9.5) are prepared, and the wrapping alloy comprises active metal, auxiliary welding metal and melting metal with the mass ratio being (15-40): (60-80): (0-10); the method comprises the following steps: mixing ceramic particles and a coating alloy, filling the mixture into a coating reaction tube, vacuumizing, heating, injecting reducing gas and / or protective gas, vacuumizing again, heating, completely reducing surface oxides of auxiliary welding metal and melting metal, vacuumizing again, heating to 900-1250 DEG C, melting the coating alloy, preserving heat, keeping the temperature at normal temperature, and cooling to room temperature. And surface metallization ceramic particles are obtained. The method is short in time, low in energy consumption and higher in production efficiency.

Description

Technical Field

[0001] The present invention relates to a preparation method of ceramic wear-resistant fittings, specifically to a preparation method of surface-metallized ceramic particles and a preparation method of ceramic wear-resistant fittings based on such ceramic particles. Background Art

[0002] In multiple industries such as mineral mining, cement production, thermal power generation, building sand making, metallurgy, chemical industry, environmental protection, construction, and dredging, a large number of crushing equipment, powder grinding equipment, tunneling equipment, dredging equipment, as well as pumps and pipelines for transporting slurry and mortar are widely used. Their main functions are to crush raw materials, grind them into powder, or transport them through pipelines. The steel working fittings in these devices usually suffer severe wear under high-intensity working conditions, such as high temperature, high pressure, and strong friction environments, resulting in short service life of the devices and high maintenance costs.

[0003] In order to improve the service life of the wear-resistant fittings of the above devices, extend the maintenance cycle of the devices, and reduce the maintenance cost, technicians have tried to combine ceramic materials with metal materials to form ceramic composites in order to obtain wear-resistant fittings with excellent performance. Existing technologies mostly use molybdenum-manganese sintering process, centrifugal self-propagating technology, silicon nitride bonded silicon carbide technology, etc. to synthesize ceramic composites, but these methods still have many limitations in practical applications. For example, although the molybdenum-manganese sintering process can improve the bonding strength between ceramics and metals, its process is complex, costly, and the connection strength of the products is limited; although the centrifugal self-propagating technology improves the wear resistance of the ceramic lining, its density is poor, the ceramics are prone to cracking in low-temperature environments, and it is difficult to manufacture pipelines with complex shapes; although the silicon nitride bonded silicon carbide technology has excellent wear resistance, its impact resistance is poor, and the manufacturing difficulty is high with a low yield.

[0004] In summary, the existing preparation methods of ceramic composites all have certain defects. Therefore, it is urgent to develop a new preparation method of ceramic composites to overcome the above problems. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problems that the existing molybdenum-manganese sintering process is complex, costly, and the connection strength of the products is limited; or the existing centrifugal self-propagating technology has poor density, is prone to cracking, and is difficult to manufacture pipelines with complex shapes; or the existing silicon nitride bonded silicon carbide technology has high manufacturing difficulty and low yield, and to provide a preparation method of surface-metallized ceramic particles and ceramic wear-resistant fittings.

[0006] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0007] A preparation method of surface-metallized ceramic particles is characterized by including the following steps:

[0008] Step 1: Prepare the coating alloy and ceramic particles with a volume ratio of 0.5 - 1.5:8.5 - 9.5. The coating alloy includes an active metal, an auxiliary welding metal, and a fusing metal with a mass ratio of 15 - 40:60 - 80:0 - 10. The active metal is at least one of titanium, titanium alloy, titanium hydride, zirconium, and chromium. The auxiliary welding metal is at least one of copper, copper alloy, nickel, and boron. The fusing metal is an alloy containing copper and titanium and having a melting point lower than 1000°C, preferably a copper-silver-titanium-boron alloy, a copper-silver-titanium alloy, a copper-titanium alloy, or a copper-titanium alloy mainly composed of titanium and copper with 20% - 50% titanium. The ceramic particles are at least one of alumina (Al2O3), zirconia (Al2O3), silicon carbide (SiC), silicon nitride (Si2N4), sialon (Sialon), titanium carbide-reinforced alumina (TiC-Al2O3 composite), titanium carbide-reinforced silicon carbide (TiC-SiC composite), titanium carbide-reinforced silicon nitride (TiC-Si3N4 composite), and silicon carbide-reinforced alumina (SiC-Al2O3 composite), and the particle size of the ceramic particles is 0.3 - 6 mm.

[0009] Step 2: After mixing the ceramic particles and the coating alloy, load them into a coating reaction tube, close the coating reaction tube or place the coating reaction tube in a closed system, and extract the gas inside the coating reaction tube through an exhaust pipe to make its vacuum degree 0.1 Kpa - 10 Kpa. Then heat the coating reaction tube to 200°C - 300°C.

[0010] Step 3: Inject a reducing gas and / or a protective gas into the coating reaction tube through an injection pipe to dilute the residual air and reduce and remove the metal surface oxides, while slowly heating up and extracting the excess gas inside the coating reaction tube, so that the vacuum degree inside the coating reaction tube is always equal to one atmospheric pressure until it is heated to 300°C - 700°C. After the metal surface oxides in the auxiliary welding metal and the fusing metal are reduced, close the injection pipe. At this time, the metal surface oxides in the auxiliary welding metal and the fusing metal are basically completely reduced.

[0011] Step 4: Extract the gas inside the coating reaction tube through an exhaust pipe to keep its internal vacuum degree 0.1 Kpa - 5 Kpa. Then keep the absolute vacuum degree stable, heat it to 900°C - 1250°C according to the heating curve to melt the coating alloy, keep it warm for 15 - 60 minutes and then cool it to room temperature to obtain surface-metallized ceramic particles. Load the surface-metallized ceramic particles into a sealed anti-oxidation bag or mix them with an anti-oxidation protective agent for standby.

[0012] Further, in Step 1, the titanium metal content in the coating alloy is 18% - 30%. Experiments show that when the titanium content in the coating alloy is about 18% - 30%, the connection strength with the ceramic particles is the highest and the energy consumption is the least.

[0013] Further, step 2 specifically includes: mixing ceramic particles with the coating alloy, loading the mixture into a coating reaction tube, sealing the coating reaction tube, placing it in a high-temperature sintering furnace, extracting the gas in the coating reaction tube through an extraction pipe to make its vacuum degree 0.1 Kpa to 10 Kpa, and then heating the coating reaction tube to 200°C to 300°C through the high-temperature sintering furnace.

[0014] Further, step 2 specifically includes: mixing ceramic particles with the coating alloy, loading the mixture into a coating reaction tube, then loading the coating reaction tube into a vacuum sintering furnace, sealing the vacuum sintering furnace, extracting the gas in the vacuum sintering furnace through an extraction pipe to make the vacuum degree in the coating reaction tube 0.1 Kpa to 10 Kpa, and then heating it to 200°C to 300°C through the vacuum sintering furnace.

[0015] Further, step 2 specifically includes: mixing ceramic particles with the coating alloy, loading the mixture into a coating reaction tube, then loading the coating reaction tube into a vacuum reaction tank, sealing the vacuum reaction tank, then placing the vacuum reaction tank in a high-temperature sintering furnace, extracting the gas in the vacuum reaction tank through an extraction pipe to make the vacuum degree in the coating reaction tube 0.1 Kpa to 10 Kpa, and then heating it to 200°C to 300°C through the high-temperature sintering furnace.

[0016] Further, step 2 specifically includes: mixing ceramic particles with the coating alloy, loading the mixture into a coating reaction tube, then sealing the coating reaction tube with a tube plug having breathable micropores, loading it into a rotatable vacuum reaction tank, sealing the vacuum reaction tank, then placing the vacuum reaction tank in a high-temperature sintering furnace, extracting the gas in the vacuum reaction tank through an extraction pipe to make the vacuum degree in the coating reaction tube 0.1 Kpa to 10 Kpa, and then heating it to 200°C to 300°C through the high-temperature sintering furnace.

[0017] In addition, the mixture of ceramic particles and the coating alloy can also be directly loaded into a rotatable vacuum reaction tank, and the vacuum reaction tank is sealed; then the vacuum reaction tank is placed in a high-temperature sintering furnace, and the extraction pipe and the injection pipe are connected to the vacuum reaction tank. When heating up, the rotation system of the vacuum reaction tank is started to make the vacuum reaction tank rotate slowly in a forward and reverse reciprocating manner to ensure that the internal materials are evenly heated and coated.

[0018] Meanwhile, the present invention also provides a preparation method for a surface metallized ceramic wear-resistant fitting, including the following steps:

[0019] Step [1]: According to the shape and size of the wear-resistant fitting, a forming cavity and a pressing mold used in cooperation with the forming cavity are made; the shape of the forming cavity is adapted to the shape of the wear-resistant fitting, and its volume is larger than the volume of the wear-resistant fitting to facilitate the compression and filling of materials during the pressing process; the pressing mold is used to press the cavity from the outside to the inside to make its inner cavity shrink.

[0020] For complex or large-sized fittings, the molding cavity can be decomposed into multiple small cavities, which are fabricated separately and then welded together to form an integral molding cavity. For simple or small-sized fittings: multiple molding cavities can be fabricated integrally and then cut into individual parts after completion. In addition, metal inserts can be installed in the molding cavity, which play three roles during the manufacturing process: first, as a connecting part between the wear-resistant fitting and the main machine; second, for connecting the disassembled fittings fabricated separately; third, as internal connecting ribs to prevent deformation of large-area fittings. The use of metal inserts provides great convenience for the installation, connection, and loading of wear-resistant fittings.

[0021] Step [2]: Prepare the gold-ceramic mixture, load it into the molding cavity, and seal the molding cavity after it is filled.

[0022] The gold-ceramic mixture includes gold-ceramic particles, metal materials, and brazing metals with a volume ratio of 3.5 - 5.5:1.5 - 5:1 - 3. The gold-ceramic particles are surface-metallized ceramic particles, or the gold-ceramic particles include clean ceramic particles and surface-metallized ceramic particles with a volume ratio of 0 - 0.8:9.2 - 10. The surface-metallized ceramic particles are prepared by the above-mentioned preparation method of surface-metallized ceramic particles. The clean ceramic particles are selected from at least one of alumina, silicon carbide, silicon nitride, sialon, and boron carbide, and the particle size of the clean ceramic particles is 0.08 mm - 0.3 mm. The metal materials are metal particles and / or metal powders. Among them, the metal particles are at least one of carbon steel alloy, stainless steel, manganese steel alloy, chromium steel alloy, and nickel steel alloy, and are annealed and softened to ensure appropriate mechanical properties and forming ability during subsequent processing. The metal particles are particles with a particle size of 0.5 mm - 2.5 mm and / or metal wires with a diameter of 0.3 mm - 1 mm and a length of 1.5 mm - 3 mm. The metal powders are metals, metal alloys, or reducible metal oxide powders with a melting point higher than the highest temperature for manufacturing wear-resistant fittings. The brazing metals are at least one of copper, copper alloy, aluminum, aluminum alloy, and boron.

[0023] Step [3]: Adjust the vacuum degree in the molding cavity, place it in a high-temperature furnace and heat it to a preset temperature, and apply pressure to the molding cavity through a pressing die to obtain a semi-finished wear-resistant fitting. The preset temperature is 20 - 200 °C above the material with the highest melting point among the brazing metal or the coating alloy of the gold-ceramic particles described in Step [2].

[0024] Step [4]: Perform heat treatment, cutting, welding, and trimming on the semi-finished wear-resistant fitting in sequence according to the preset process requirements to obtain a surface-metallized ceramic wear-resistant fitting.

[0025] Further, in step [2], when local enhancement of the wear-resistant fitting is required, an enhanced gold-ceramic mixture needs to be separately prepared. The enhanced gold-ceramic mixture includes gold-ceramic particles, metal materials, and brazing metals with a volume ratio of 5.2 - 6.2: 0 - 1.5: 3 - 3.8.

[0026] Further, step [3] is specifically as follows:

[0027] 3.1. Exhaust the gas in the forming cavity through the exhaust pipe until the vacuum degree reaches 0.05 - 0.2 atmospheres, then stop exhausting; fill the forming cavity with reducing gas and / or protective gas until the vacuum degree is equal to 1 atmosphere;

[0028] 3.2. Heat the forming cavity to a preset temperature through a high-temperature furnace and then keep it warm, so that the temperatures inside and outside the forming cavity are the same. During the heating and heat preservation periods, keep the air pressure in the forming cavity equal to 1 atmosphere;

[0029] 3.3. Close the exhaust pipe, place the forming cavity that has reached the preset temperature into a pressing mold for pressure shaping to obtain a semi-finished wear-resistant fitting.

[0030] Further, in step [1], the forming cavity includes a cavity shell and a cavity cover connected to the cavity shell;

[0031] The exhaust pipe is arranged on the cavity shell or the cavity cover for exhausting the gas in the cavity, and a separation net is installed at the interface between the exhaust pipe and the cavity shell or the cavity cover to prevent material loss;

[0032] Alternatively, the exhaust pipe is arranged on the cavity shell or the cavity cover, and an overflow bin is connected to the exhaust pipe. The overflow bin is communicated with the forming cavity through the exhaust pipe for collecting excess materials to ensure uniform distribution of materials in the forming cavity; a separation net is installed at the entrance of the overflow bin;

[0033] In step 3.2, the high-temperature furnace adopts a method of segmented heating and segmented pressurization during the heating process;

[0034] In step 3.3, during the pressure shaping process, the overflow bin is always communicated with the forming cavity and the overflow bin is kept warm; at the same time, the forming cavity is cooled first from the end far away from the overflow bin through a temperature control system, and the cooling rate is controlled to prevent deformation or cracks caused by thermal stress.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] (1) The preparation method of the surface-metallized ceramic particles of the present invention involves coating ceramic particles with an active metal and promoting the reaction between the active metal and the ceramic particles in a vacuum environment at 900°C to 1250°C to form surface-metallized ceramic particles. This method has a lower sintering temperature and a shorter sintering time compared to the traditional molybdenum-manganese sintering process, greatly reducing energy consumption.

[0037] (2) When preparing the surface-metallized ceramic particles of the present invention, a low-melting-point fusing metal is introduced, which accelerates the melting rate of the active metal and the auxiliary soldering metal and reduces their relative melting points. The fusing metal melts at a lower temperature, promoting the faster melting of other metals and their reaction with the ceramic to form an extended droplet zone, further increasing the melting rate of the coating alloy, reducing energy consumption, and improving the equipment utilization efficiency.

[0038] (3) The present invention coats the surface of ceramic particles with an active metal alloy to produce surface-metallized ceramic particles for use in the manufacture of wear-resistant fittings. This method significantly improves the wear resistance of the fittings and can optimize the ratio of the active metal and the auxiliary soldering metal as needed to increase the connection strength and wear resistance while reducing the manufacturing cost. In addition, this process shortens the reaction time, reduces energy consumption, and optimizes production efficiency.

[0039] (4) The present invention calculates the amount of the coating alloy based on the particle size of the ceramic particles to ensure a uniform coating thickness. At the same time, according to the production demand of the ceramic-metal particles, different production methods are used, especially by using a rotatable vacuum reaction tank and a coating reaction tube placed inside the vacuum reaction tank to avoid unevenness during heating and ensure that the mechanical properties of the produced surface-metallized ceramic particles are consistent everywhere.

[0040] (5) By using a reducing gas and / or a protective gas during the coating process, the present invention can effectively remove oxygen and reduce the residual amount of nitrogen, thereby protecting the active metal from being affected by reactions with oxygen and nitrogen and avoiding the influence on the product performance. At the same time, it can also eliminate the oxide layer on the surface of the auxiliary soldering metal, improve the coating strength, and effectively control the production cost.

[0041] (6) The surface-metallized ceramic particles prepared by the present invention have excellent properties. For example, the connection strength between the Cu-Ni-Ti alloy and silicon nitride ceramic can reach 298 MPa, far exceeding the traditional molybdenum-manganese method. However, due to the high content of unreacted titanium elements in the coating alloy, the coating alloy has poor toughness and high brittleness. When preparing wear-resistant fittings, through high-temperature pressing and brazing metal fusion, the distribution and content of titanium elements in the brazing alloy can be effectively changed, greatly improving the flexibility and impact resistance of the material, which cannot be achieved by the existing technology.

[0042] (7) The present invention ensures the uniform distribution of materials at high temperatures by compacting the gold-ceramic mixture at high temperatures, eliminating voids and sand holes in the forming cavity, thereby improving the quality and brazing effect of wear-resistant fittings and ensuring higher wear resistance and stability of the fittings during use.

[0043] (8) When preparing wear-resistant fittings, the present invention adopts a method of staged pressurization and heating during the period when the forming cavity is heated to the set maximum temperature, so that the metal particles in the forming cavity are gradually deformed under extrusion, enabling them to closely adhere to the surrounding gold-ceramic particles, gradually increasing the density of the material, and ensuring the uniformity and density of the final product.

[0044] (9) The present invention can use metal powder to replace part or all of the metal particles, which can improve the fluidity of the gold-ceramic mixture, greatly reduce the pressurization intensity and manufacturing difficulty. This process is particularly suitable for manufacturing large-sized and complex-shaped wear-resistant fittings, ensuring uniform internal structure and higher quality.

[0045] (10) During the pressurization manufacturing process of the present invention, the overflow bin can collect excessive gold-ceramic mixture, preventing defects caused by volume shrinkage during the cooling of the fittings. During cooling, the gold-ceramic mixture in the overflow bin can be supplemented into the fittings to ensure a perfect shape of the finished product. Description of the Drawings

[0046] Figure 1 It is a schematic structural diagram of the tooling for firing surface-metallized ceramic particles using a long-shaped sintering furnace in Embodiment 1 of the present invention;

[0047] Figure 2 It is a schematic structural diagram of the forming cavity and the pressing die for preparing a wear-resistant flat guard plate in Embodiment 1 of the present invention;

[0048] Figure 3 It is a schematic cross-sectional comparison diagram of the forming cavity before and after compacting in Embodiment 1 of the present invention;

[0049] Figure 4 It is a schematic structural diagram of the tooling for firing surface-metallized ceramic particles using a vacuum sintering furnace in Embodiment 2 of the present invention;

[0050] Figure 5 It is a schematic cross-sectional structure diagram of the forming cavity compacting in Embodiment 2 of the present invention;

[0051] Figure 6 It is a schematic structural diagram of the tooling for firing surface-metallized ceramic particles using a circular sintering furnace and a vacuum reaction tank in Embodiment 3 of the present invention;

[0052] Figure 7 It is a schematic structural diagram of the forming cavity and the pressing die in Embodiment 3 of the present invention;

[0053] Figure 8 It is a schematic structural diagram of the forming cavity of the wear-resistant gold-ceramic ball before closing in the fourth embodiment of the present invention;

[0054] Figure 9 It is a schematic structural diagram of the forming cavity of the wear-resistant gold-ceramic ball during pressing and forming in the fourth embodiment of the present invention;

[0055] Figure 10 It is a longitudinal tooling structure sectional view of firing surface-metallized ceramic particles using a horizontal sintering furnace in the fifth embodiment of the present invention;

[0056] Figure 11 It is a transverse tooling structure sectional view of firing surface-metallized ceramic particles using a horizontal sintering furnace in the fifth embodiment of the present invention;

[0057] Figure 12 It is a schematic structural diagram of the forming cavity and the pressing die in the fifth embodiment of the present invention;

[0058] Figure 13 It is a schematic sectional structure diagram of the forming cavity in the sixth embodiment of the present invention;

[0059] Figure 14 It is a schematic structural diagram of the forming cavity before welding in the sixth embodiment of the present invention;

[0060] Figure 15 It is a schematic sectional view of the forming cavity in the sixth embodiment of the present invention;

[0061] Figure 16 It is a transverse sectional view of the rotary pressing forming cavity in the seventh embodiment of the present invention;

[0062] Figure 17 It is a longitudinal sectional view of the rotary pressing forming cavity in the seventh embodiment of the present invention;

[0063] Figure 18 It is a transverse sectional view of the forming cavity pressed by the composite die set in the eighth embodiment of the present invention;

[0064] Figure 19 It is a schematic structural diagram of the forming cavity in the eighth embodiment of the present invention;

[0065] Figure 20 It is a schematic structural diagram of several corrugated steel bars used in the eighth embodiment of the present invention.

[0066] The description of the reference numerals is as follows:

[0067] 1 - Coating reaction tube; 2 - Ceramic mixture; 3 - Tube cover; 4 - Exhaust pipe; 5 - Injection pipe; 6 - Metal-ceramic mixture; 7 - Chamber shell; 8 - Chamber cover; 9 - Isolation net; 10 - Exhaust pipe; 11 - Extrusion moving die; 12 - Extrusion fixed die; 13 - Flash bin; 14 - Heating furnace; 15 - First welding seal; 16 - Second welding seal; 17 - Long sintering furnace; 18 - Vacuum sintering furnace; 19 - Circular sintering furnace; 20 - Horizontal sintering furnace; 21 - Chamber pressure moving die; 22 - Chamber pressure forming die set; 23 - Ejector rod; 30 - Vacuum reaction tank; 31 - Rolling forming die set; 32 - Arc surface opposed roller; 41 - Chamber pressure arc surface moving die; 42 - Chamber pressure arc surface forming die set; 43 - Chamber pressure arc surface ejector rod; 50 - Horizontal vacuum reaction tank; 51 - Rotary precession pipe expanding and pressing fixed die; 52 - Pipe expanding and pressing rotary moving die; 53 - Pipe expanding roller; 54 - Reaction tank rotating shaft; 55 - Shaft support seat; 56 - Horizontal sintering furnace door; 61 - Chamber pressure fixed die; 62 - Chamber pressure moving die; 63 - Chamber pressure center pressing die; 64 - Ring; 65 - Shaft connecting piece; 66 - Shape-preserving sand; 71 - Spinning moving die; 72 - Spinning inner support fixed die; 73 - Spinning roller; 81 - Inner pipe expanding die; 82 - Expanding and pressing roller; 83 - Outer pipe shrinking die; 751 - First outer pipe; 752 - First inner pipe; 761 - Rear plate outer shell; 762 - Rear plate inner shell; 763 - Blade shell; 764 - Front plate inner shell; 765 - Front plate outer shell; 771 - Second inner pipe; 772 - Second outer pipe; 781 - Outer sleeve; 782 - Inner sleeve; 783 - Corrugated steel strip. Detailed implementation manners

[0068] To make the objectives, advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0069] Embodiment 1

[0070] This embodiment provides a method for preparing surface-metallized ceramic particles, including the following steps:

[0071] Step 1: Prepare a coating alloy and ceramic particles with a volume ratio of 0.68:9.32. Among them, the ceramic particles are alumina with a particle size of 2.2 - 2.5 mm; the coating alloy is selected as an active metal, an auxiliary welding metal, and a fusing metal with a mass ratio of 25:73:2; the active metal is titanium (powder), the auxiliary welding metal is copper (powder), and the fusing metal is copper-titanium alloy particles containing 20% titanium.

[0072] Step 2: As Figure 1As shown in the figure, the ceramic particles selected in Step 1 are evenly mixed with the cladding alloy to obtain the ceramic mixture 2. When preparing the ceramic mixture, a small amount of binder that can be heated and decomposed, has good volatility, no residue, and does not affect the performance and process of the surface-metallized ceramic particles can be added, which can adhere the powder in the ceramic mixture to the granular material. Then, the ceramic mixture 2 is loaded into the cladding reaction tube 1, and the cladding reaction tube 1 is sealed with the tube cap 3. Then, the cladding reaction tube 1 is respectively connected to the exhaust pipe 4 and the injection pipe 5, and placed in the long sintering furnace 17. Then, the exhaust equipment is respectively connected to the exhaust pipe 4 and the injection pipe 5 to adjust the vacuum degree of the cladding reaction tube 1. The gas in the cladding reaction tube 1 is pumped out through the exhaust pipe 4 to make the vacuum degree in the cladding reaction tube 1 be 0.1 - 10 Kpa. The cladding reaction tube 1 is heated to 250°C through the long sintering furnace 17. The exhaust pipe 4 and the injection pipe 5 can be installed separately to continuously control the gas in the cladding reaction tube 1, or they can be installed in the same tube to alternately and intermittently control the gas in the cladding reaction tube 1.

[0073] Step 3: Slowly inject the reducing gas and / or protective gas into the cladding reaction tube 1 using the injection pipe 5, keep heating continuously, and slowly raise the temperature. At the same time, use the exhaust equipment to pump out the excess gas in the cladding reaction tube 1 to keep the vacuum degree in the cladding reaction tube 1 always equal to one atmospheric pressure. When the temperature rises to 650°C and the metal surface oxides in the auxiliary welding metal and the fusing metal are completely reduced, close the injection pipe 5.

[0074] Step 4: Pump out the gas in the cladding reaction tube 1 through the exhaust pipe 4 to make the vacuum degree in the cladding reaction tube 1 be 0.1 - 5 Kpa. Keep the vacuum degree stable, heat the cladding reaction tube 1 to 1100°C according to the heating curve to melt the cladding alloy. Keep it warm for 15 minutes to make the cladding alloy and the surface of the ceramic particles undergo a composite reaction. Then cool it down to room temperature to obtain the surface-metallized alumina ceramic particles, and load them into an airtight anti-oxidation bag for standby.

[0075] This embodiment has a lower sintering temperature and a shorter sintering time than the traditional molybdenum-manganese method sintering process, greatly reducing the energy consumption. For example, using a copper-titanium alloy containing about 20% titanium metal, which has a low melting point (870°C - 920°C), enables the subsequent process to be completed below 1000°C, thus simplifying the manufacturing process and reducing the equipment requirements.

[0076] Taking the wear-resistant flat guard plate (arc guard plate) based on the above surface-metallized alumina ceramic particles as an example, its preparation method is introduced. The length of the wear-resistant flat guard plate is 800 mm, and its cross-section is a rectangular structure with a width of 400 mm and a thickness of 25 mm. And the alumina ceramic particles in the wear-resistant layer of the wear-resistant flat guard plate account for 35 - 38% of the volume ratio. Its specific preparation method includes the following steps:

[0077] Step [1], fabricate the forming cavity and the pressing mold

[0078] Fabricate the forming cavity: Extrude a long thin-walled circular tube with a wall thickness of 1 mm, a diameter of 270 mm, and a length slightly greater than 4000 mm into a cavity shell 7 with a rectangular-like cross-section thickness of 35 mm for the inner cavity. Then, narrow one end of the cavity shell 7 to form a rectangular pipe opening with a width of 400 mm and a thickness of 25 mm (as shown in Figure 2 and Figure 3 ). Next, fabricate two cavity covers 8 that can be inserted into the corresponding pipe openings according to the shapes and sizes of the pipe openings at both ends of the cavity shell 7. An exhaust pipe 10 is installed on the larger-sized cavity cover 8, and an overflow bin 13 is provided on the exhaust pipe 10. The overflow bin 13 is communicated with the cavity shell 7 through the exhaust pipe 10, and a separator net 9 is installed at the interface between the exhaust pipe 10 and the cavity shell 7. Insert the other smaller-sized cavity cover 8 into the pipe opening at the other end of the cavity shell 7. During use, then use the first welding seal 15 and the second welding seal 16 to weld the two cavity covers 8 to the cavity shell 7 respectively to form a sealed forming cavity.

[0079] For wear-resistant fittings with simple shapes or small volumes, multiple forming cavities can be connected together for integrated fabrication and then cut into independent individuals. This method can simplify the production steps and improve production efficiency, and is suitable for mass production.

[0080] For complex or large-volume wear-resistant fittings, the sealed forming cavity can be decomposed into multiple small cavities, fabricated separately and then welded and combined. This method greatly reduces the fabrication difficulty of large and complex fittings, and realizes the simple production of complex fittings and the miniaturized manufacturing of large fittings.

[0081] Fabricate the pressing mold for pressing the sealed forming cavity: Fabricate a progressive displacement and thickness-fixed extrusion-type moving mold 11 and an extrusion-type fixed mold 12. The final width of the extrusion-type moving mold 11 and the extrusion-type fixed mold 12 is 400 mm, and the thickness is 25 mm, which is consistent with the dimensional requirements of the wear-resistant flat guard plate.

[0082] Step [2], prepare a uniformly mixed gold-ceramic mixture 6 according to the proportional requirements, and then load the gold-ceramic mixture 6 into the forming cavity. After filling, seal the forming cavity.

[0083] The gold-ceramic mixture 6 in this embodiment is a gold-ceramic particle, a metal material, and a brazing metal with a volume ratio of 3.5:4.5:2. Among them, the gold-ceramic particle is the surface-metallized alumina ceramic particle prepared by the aforementioned method; the metal material contains 50% metal particles and 50% metal powder. The metal particles are 45# steel particles with a copper coating on the surface, the particle size is 1.8 - 2 mm, and they need to be annealed and softened. The metal powder is iron powder with a particle size of 320 μm; the brazing metal is copper powder or copper particles.

[0084] Load the above-mentioned gold-ceramic mixture 6 into the cavity shell 7 from the position of the cavity cover 8. During the loading process, vibrate, tamp, or press mechanically while loading, so that the gold-ceramic mixture 6 can be densely filled in the cavity shell 7. After filling, weld the cavity cover 8 and the cavity shell 7 together by secondary welding to form a sealed forming cavity.

[0085] Step [3], Start gas control and heating

[0086] Replace the gas, extract the gas in the forming cavity through the exhaust pipe 10 until the vacuum degree in the forming cavity reaches 0.1 - 0.2 atmospheres, then stop pumping. Fill the forming cavity with reducing gas and protective gas until its vacuum degree reaches 0.8 - 1 atmosphere.

[0087] Place the forming cavity into the heating furnace 14 and heat it up until the set maximum temperature of 1100 °C, then keep it warm to make the temperature inside and outside the forming cavity uniform. During the heating-up period, keep the vacuum degree in the forming cavity always equal to 1 atmosphere.

[0088] Seal the exhaust pipe 10, and place the forming cavity that has reached the preset maximum temperature into the extrusion moving die 11 and the extrusion fixed die 12 for pressure shaping. During the pressure shaping, the overflow bin 13 needs to be always connected to the forming cavity, and at the same time, keep the overflow bin 13 warm to ensure that the excess material can be discharged smoothly during pressurization. In addition, during the shaping process, it is necessary to cool first from the place far away from the opening of the overflow bin 13 (that is, the overflow bin 13 cools last), and control the cooling rate to prevent deformation or cracks caused by thermal stress, and finally make a semi-finished product of the wear-resistant flat plate.

[0089] Step [4], Post-treatment

[0090] According to the preset process requirements, perform heat treatment, cutting, welding, and trimming on the semi-finished product of the wear-resistant flat plate in sequence, so as to obtain the finished product of the wear-resistant flat plate. Among them, heat treatment is used to improve the mechanical properties and internal structure of the material; cutting, welding, and trimming are used to ensure that the finished product meets the design requirements and usage standards.

[0091] The above preparation method is also applicable to wear-resistant arc-shaped plates and connected wear-resistant ball (rod) mill liners.

[0092] Example Two

[0093] This example provides a preparation method for surface-metallized ceramic particles, including the following steps:

[0094] Step 1: Prepare a cladding alloy and ceramic particles with a volume ratio of 0.63:9.37. Among them, the ceramic particles are alumina with a particle size of 2.5 - 2.8 mm; the cladding alloy is composed of reactive metal, auxiliary welding metal, and fusing metal with a mass ratio of 21:77:2. The reactive metal is titanium powder, the auxiliary welding metal is copper powder, and the fusing metal is a copper-titanium alloy containing 20% titanium.

[0095] Step 2: As Figure 4 shown, mix the ceramic particles selected in Step 1 with the cladding alloy evenly to obtain a ceramic mixture 2, and load the ceramic mixture 2 into the cladding reaction tube 1; then place the cladding reaction tube 1 evenly in the vacuum sintering furnace 18; then connect the air extraction pipe 4 and the gas injection pipe 5 on the vacuum sintering furnace 18 to the corresponding equipment; seal the vacuum sintering furnace 18; extract the gas in the vacuum sintering furnace 18 and the cladding reaction tube 1 through the air extraction pipe 4 to make the vacuum degree in the cladding reaction tube 1 0.1 - 10 Kpa; heat the cladding reaction tube 1 to 280 °C through the vacuum sintering furnace 18.

[0096] Step 3: Slowly inject reducing gas and / or protective gas into the vacuum sintering furnace 18 and the cladding reaction tube 1 using the gas injection pipe 5, keep heating continuously, and slowly raise the temperature; at the same time, use the air extraction vacuum equipment to extract the excess gas in the vacuum sintering furnace 18 and the cladding reaction tube 1, and synchronously keep the vacuum degree in the furnace always equal to 1 atmospheric pressure; when the temperature rises to 600 °C, after the metal surface oxides in the auxiliary welding metal and the fusing metal are completely reduced, close the gas injection pipe 5.

[0097] Step 4: Extract the gas in the cladding reaction tube 1 through the air extraction equipment 4 to make the vacuum degree in the cladding reaction tube 1 0.1 - 5 Kpa; keep the vacuum degree stable, heat the cladding reaction tube 1 to 1100 °C according to the heating curve to melt the cladding alloy; keep warm for 25 minutes to make the composite reaction occur on the surface of the cladding alloy and the ceramic particles; then cool down to room temperature to obtain surface metallized alumina ceramic particles, and load them into an airtight anti-oxidation bag or coat them with an anti-oxidation isolation agent for standby.

[0098] Taking the wear-resistant ball mill lining plate based on the above surface metallized alumina ceramic particles as an example, this embodiment introduces its preparation method. The wear-resistant ball mill lining plate is a cuboid structure with a length of 600 mm, and its cross-section is a rectangular structure with a width of 350 mm and an average thickness of 65 mm. And in the wear-resistant layer of the wear-resistant ball mill lining plate, the alumina ceramic particles account for 35 - 38% of the volume ratio. Its specific preparation method includes the following steps:

[0099] Step [1]: Make the forming cavity and the pressing die

[0100] Make the forming cavity: As Figure 5, a long circular tube with a wall thickness of 1.5 mm, a diameter of 265 mm, and a length of 600 mm is made into a cuboid-shaped cavity shell 7 with an inner cavity thickness greater than 65 mm. At the same time, both ends of the cavity shell 7 are made into rectangular pipe orifices with a cross-section of 350 mm wide and 65 mm thick. A head is made for each of the two pipe orifices, and one end of the pipe orifice is sealed with the head. An exhaust pipe 10 is installed in the middle of the cavity shell 7, and a separation net 9 is provided at the interface between the exhaust pipe 10 and the cavity shell 7; the head at the other end of the pipe orifice serves as a cavity cover. During use, the cavity cover 8 is hermetically connected to the cavity shell 7 to form a sealed forming cavity.

[0101] Manufacture a pressing mold: The pressing mold is a cavity-pressure forming mold set 22 with an ejector rod 23 and a cavity-pressure moving mold 21, and its final sizing is 600 mm × 350 mm × 65 mm.

[0102] Step [2], prepare a uniformly mixed gold-ceramic mixture 6 according to the proportional requirements, and then load the gold-ceramic mixture 6 into the forming cavity. After filling, seal the forming cavity.

[0103] The gold-ceramic mixture 6 in this embodiment is gold-ceramic particles, a metal material, and a brazing metal with a volume ratio of 4:3:3. Among them, the gold-ceramic particles are clean ceramic particles and surface-metallized alumina ceramic particles prepared by the aforementioned method with a volume ratio of 0.8:9.2; the metal material selected is chromium 12 steel particles with a particle size of 1.5 - 1.8 mm, and they need to be annealed and softened; the brazing metal is copper (powder).

[0104] First, install the fixing metal parts of the wear-resistant ball mill liner at the corresponding positions in the forming cavity, and then load the above gold-ceramic mixture 6 into the cavity shell 7 from the position of the cavity cover 8. During the loading process, vibrate, tamp, or press with a machine while loading, so that the gold-ceramic mixture 6 can be densely filled in the cavity shell 7; after filling, weld the cavity cover 8 and the cavity shell 7 together by secondary welding to form a sealed forming cavity.

[0105] Step [3], start gas control and heating

[0106] Replace the gas, extract the gas in the forming cavity through the exhaust pipe 10 until the vacuum degree in the forming cavity reaches 0.1 - 0.2 atmospheres, then stop pumping; fill the forming cavity with a reducing gas and a protective gas until it reaches 0.5 - 0.8 atmospheres.

[0107] Place the forming cavity in a heating furnace 14 and heat it up to the set maximum temperature of 1100 °C and then keep it warm to make the temperature inside and outside the forming cavity uniform. During the heating period, keep the vacuum degree in the forming cavity always equal to 1 atmosphere.

[0108] Extract the gas in the forming cavity, then seal the exhaust pipe 10, and place the forming cavity that has reached the preset maximum temperature into the cavity pressure forming die set 22 for pressure setting to obtain a semi-finished wear-resistant ball mill liner.

[0109] Step [4] Post-treatment

[0110] According to the preset process requirements and the post-treatment method of Example 1, obtain the wear-resistant ball mill liner.

[0111] The above preparation method is also applicable to wear-resistant arc-shaped protective plates and connected wear-resistant ball (rod) mill liners.

[0112] Example 3

[0113] This example provides a preparation method for surface-metallized ceramic particles, including the following steps:

[0114] Step 1: Prepare three combinations of coated alloy and ceramic particles, namely: the volume ratio of coated alloy to 5.8 - 6 mm ceramic particles is 0.5:9.5; the volume ratio of coated alloy to 1.8 - 2 mm ceramic particles is 0.75:9.25; the volume ratio of coated alloy to 0.8 - 1 mm ceramic particles is 1.05:8.95. Among them, the coated alloy is titanium copper nickel alloy powder, which includes active metal and auxiliary welding metal with a mass ratio of 39:61. The active metal is selected as titanium, and the auxiliary welding metal is selected as copper and nickel with a mass ratio of 34:27; the ceramic particles are silicon nitride and / or silicon carbide particles.

[0115] Step 2: As Figure 6 shown, mix the three combinations selected in Step 1 evenly respectively to obtain three groups of ceramic mixtures 2, and load them into the corresponding coated reaction tubes 1 respectively; then load all the coated reaction tubes 1 into the vacuum reaction tank 30 in an orderly manner and seal the vacuum reaction tank 30; then place the vacuum reaction tank 30 into the circular sintering furnace 19; then connect the exhaust pipe 4 and the injection pipe 5 on the vacuum reaction tank 30 to the corresponding equipment; extract the gas in the vacuum reaction tank 30 and the coated reaction tube 1 through the exhaust pipe 4 to make the vacuum degree in the coated reaction tube 1 be 0.1 - 10 Kpa; heat the coated reaction tube 1 to 200 °C through the circular sintering furnace 19.

[0116] Step 3: Slowly inject reducing gas and / or protective gas into the vacuum reaction tank 30 and the coated reaction tube 1 using the injection pipe 5, keep heating continuously and slowly raise the temperature; at the same time, extract the excess gas in the vacuum reaction tank 30 and the coated reaction tube 1 through the exhaust pipe 4 to keep the vacuum degree in the vacuum reaction tank 30 always equal to 1 atmospheric pressure; when the temperature rises to 700 °C, after the metal surface oxides of the auxiliary welding metal are completely reduced, close the injection pipe 5.

[0117] Step 4: Use the extraction pipe 4 to extract the gas in the vacuum reaction tank 30 and the coating reaction tube 1, so that the vacuum degree in the coating reaction tube 1 is 0.1 - 5 Kpa; keep the vacuum degree stable, heat the coating reaction tube 1 to 1250 °C according to the heating curve to melt the coating alloy; keep it warm for 20 - 25 minutes to cause a composite reaction between the coating alloy and the surface of the ceramic particles; then cool it down to room temperature to obtain three groups of surface metallized ceramic particles, and pack them into airtight anti-oxidation bags or coat them with anti-oxidation isolation agents for later use.

[0118] In this embodiment, taking the gold-ceramic nail (replacing the tungsten nail with a metal composite ceramic nail) based on the above-mentioned surface metallized ceramic particles as an example, the gold-ceramic nail is a gold-ceramic nail made of copper alloy composite silicon nitride or silicon carbide ceramic with a diameter of and a length of 35 mm - 50 mm, which is mainly used for inlaying on wear-resistant crushing equipment, pressure rollers, grinding rollers, and tunneling teeth, and can replace tungsten nails. The preparation method of the gold-ceramic nail is as follows:

[0119] Step [1]: Make a forming cavity and a pressing mold (as Figure 7 shown)

[0120] Make a sealed forming cavity: Use a steel straight pipe with a diameter greater than and a wall thickness of 2 mm to make a connected sealed forming cavity. One end of the forming cavity is welded and sealed with a cavity cover 8, and an exhaust pipe 10 is installed on the other end cavity cover 8. An overflow bin 13 (the same as Figure 2 ) is installed on the exhaust pipe 10, and the inside of the forming cavity is subjected to cleaning or anti-rust treatment.

[0121] Make a pressing mold: Make an extension forming mold set 31 of arc-shaped opposing rollers 32 with upper and lower arc surfaces, and its final set diameter is

[0122] Step [2]: Prepare a uniformly mixed gold-ceramic mixture 6 according to the proportional requirements, and then load the gold-ceramic mixture 6 into the forming cavity.

[0123] The gold-ceramic mixture 6 in this embodiment is a gold-ceramic mixture, metal material, and brazing metal with a volume ratio of 4.5:3.8:1.7; among them, the gold-ceramic particles are the surface metallized ceramic particles prepared by the aforementioned method, those with a particle size of 5.8 - 6 mm account for 8 - 10% of the volume ratio, those with a particle size of 0.8 - 1 mm account for 30 - 32% of the volume ratio, and those with a particle size of 1.8 - 2 mm account for 5 - 6% of the volume ratio; the metal material is selected as chromium 12 steel particles that have been annealed and softened, with a particle size of 1 - 1.2 mm; the brazing metal is a copper-nickel alloy powder with a mass ratio of 90:10.

[0124] The above-mentioned gold-ceramic mixture 6 is filled into the forming cavity from the position of the cavity cover 8. During the filling process, while filling, it is vibrated, tamped, or mechanically pressed to make the gold-ceramic mixture 6 densely fill the forming cavity shell. After being filled, the cavity cover 8 and the cavity shell 7 are welded together by secondary welding to form a sealed forming cavity.

[0125] Step [3], evacuate and heat

[0126] Replace the gas, extract the gas in the forming cavity through the exhaust pipe 10 until the vacuum degree in the forming cavity reaches 0.1 - 0.2 atmospheres, then stop pumping; fill the forming cavity with reducing gas and protective gas until its vacuum degree reaches 0.6 - 0.9 atmospheres.

[0127] Place the forming cavity into the heating furnace 14 and heat it up to the set maximum temperature of 1200 °C and then keep it warm to make the temperature inside and outside the forming cavity uniform. During the heating period, keep the vacuum degree in the forming cavity always equal to 1 atmosphere. Seal the exhaust pipe 10, place the forming cavity that has reached the preset maximum temperature into the rolling forming die set 31 for pressure setting to obtain a semi-finished wear-resistant gold-ceramic nail.

[0128] Step [4], post-treatment

[0129] According to the preset process requirements and the post-treatment method of Example 1, obtain the finished wear-resistant gold-ceramic nails. Embed the wear-resistant gold-ceramic nails into the gold-ceramic nail installation holes on the pressing roller, grinding roller, crushing equipment, and tunneling teeth, and then wear-resistant pressing roller sleeves, grinding roller sleeves, crushing workpieces, tunneling teeth and other equipment can be made.

[0130] Example 4

[0131] This example provides a preparation method of surface metallized ceramic particles, including the following steps:

[0132] Step 1, prepare two combinations of coating alloy and ceramic particles, which are respectively: the volume ratio of coating alloy to 5.8 - 6 mm ceramic particles is 0.5:9.5; the volume ratio of coating alloy to 0.5 - 0.8 mm ceramic particles is 1.25:8.75; the ceramic particles are selected as alumina particles; the coating alloy is an active metal, an auxiliary welding metal, and a fusing metal with a mass ratio of 25:74:1; the active metal is titanium powder; the auxiliary welding metal is copper powder; the fusing metal is a copper-titanium alloy containing 20% titanium.

[0133] Step 2, mix the two combinations selected in Step 1 evenly respectively to obtain two groups of ceramic mixtures 2, and fill them into the corresponding coating reaction tubes 1 respectively; then place all the coating reaction tubes 1 evenly in the vacuum sintering furnace 18 ( Figure 4as shown); then connect the air extraction pipe 4 and the gas injection pipe 5 on the vacuum sintering furnace 18 to the corresponding equipment; seal the vacuum sintering furnace 18; extract the gas in the vacuum sintering furnace 18 and the coating reaction tube 1 through the air extraction pipe 4 to make the vacuum degree in the coating reaction tube 1 be 0.1 - 10 Kpa; heat the coating reaction tube 1 to 300 °C through the vacuum sintering furnace 18.

[0134] Steps 3 and 4 are the same as Steps 3 and 4 in Example 2, obtaining two groups of surface metallized alumina ceramic particles, and respectively packing them into airtight anti-oxidation bags or coating them with anti-oxidation isolation agents for standby.

[0135] Taking the wear-resistant ceramic-metal balls based on the above-mentioned surface metallized alumina ceramic particles as an example in this embodiment, the wear-resistant ceramic-metal balls can replace the steel balls used in ball mills, and their specifications are diameters of metal composite alumina ceramic balls, and the following introduces their preparation method:

[0136] Step 【1】, fabricate the forming cavity and the pressing die

[0137] Fabricate the forming cavity: As Figure 8 and Figure 9 shown, use a long strip-shaped circular tube with a wall thickness of 2 mm, a diameter of 160 mm (less than the diameter of the to-be-made ceramic-metal ball), and an appropriate length to fabricate the forming cavity. First, heat-shrink the two ends of the long strip-shaped circular tube to make an approximately elliptical can-shaped cavity shell 7 with holes at both ends, and then fabricate two end caps as cavity covers 8 according to the hole diameter. One of the cavity covers 8 is welded to the bottom of the cavity shell 7 by secondary welding, and the other cavity cover 8 is drilled and welded to the other end of the cavity shell 7, and an exhaust pipe 10 is connected to this section. During use, seal the cavity cover 8 and the cavity shell 7 to form a sealed forming cavity.

[0138] Fabricate the pressing die: Fabricate a cavity pressure arc-shaped forming die set 42 with a cavity pressure arc-shaped ejector rod 43 and a cavity pressure arc-shaped moving die 41, and its final sizing dimension is the diameter consistent with the size of the ceramic-metal ball.

[0139] Step 【2】, prepare a uniformly mixed ceramic-metal mixture 6 according to the proportional requirements, and then load the ceramic-metal mixture 6 into the forming cavity. After filling, seal the forming cavity.

[0140] In this embodiment, the ceramic-metal mixture 6 is a ceramic-metal particle, a metal material, and a brazing metal with a volume ratio of 5.5:1.5:3; among them, the ceramic-metal particles are the surface metallized alumina ceramic particles prepared by the aforementioned method; the metal material is a 45# steel powder with a particle size of 120 microns; the brazing metal is copper powder or copper particles.

[0141] Load the above-mentioned gold-ceramic mixture 6 into the molding cavity from the position of the cavity cover 8. During the loading process, vibrate, tamp, or mechanically press while loading, so that the gold-ceramic mixture 6 can be densely filled in the molding cavity; after filling, weld the cavity cover 8 and the cavity shell 7 together by secondary welding to form a sealed molding cavity.

[0142] Step [3], Start gas control and heating

[0143] Replace the gas, extract the gas in the molding cavity through the exhaust pipe 10 until the vacuum degree in the molding cavity reaches 0.1 - 0.2 atmospheres, then stop pumping; fill the molding cavity with reducing gas and protective gas until it reaches 0.8 - 1 atmosphere.

[0144] Place the molding cavity into the heating furnace 14 and heat it up to the set maximum temperature of 1100 °C and then keep it warm to make the temperature inside and outside the molding cavity uniform. During the heating period, keep the vacuum degree in the molding cavity always equal to 1 atmosphere. Extract the gas in the molding cavity, seal the exhaust pipe 10, and place the molding cavity that has reached the preset maximum temperature into the cavity pressure type arc surface molding die set 42 for pressure shaping to finally obtain a semi-finished wear-resistant gold-ceramic ball.

[0145] Step [4] Post-treatment

[0146] According to the preset process requirements and the post-treatment method of Example 1, obtain the finished wear-resistant gold-ceramic balls.

[0147] Example 5

[0148] This example provides a preparation method for surface-metallized ceramic particles, including the following steps:

[0149] Step 1, Prepare four combinations of coated alloy and ceramic particles, namely: the volume ratio of coated alloy to 5.8 - 6 mm ceramic particles is 0.5:9.5; the volume ratio of coated alloy to 1.8 - 2 mm ceramic particles is 0.75:9.25; the volume ratio of coated alloy to 0.8 - 1 mm ceramic particles is 1.05:8.95; the volume ratio of coated alloy to 0.3 - 0.5 mm ceramic particles is 1.5:8.5; among them, the ceramic particles are alumina particles; the coated alloy is an active metal, a secondary welding metal, and a fusing metal with a mass ratio of 22:75:3. The active metal is titanium powder, the secondary welding metal is copper particles, and the fusing metal is a copper-titanium alloy containing 20% titanium.

[0150] Step 2: Mix the four combinations selected in Step 1 evenly respectively to obtain four groups of ceramic mixtures 2, and then load them into the corresponding coating reaction tubes 1 respectively, and block the inlet of the coating reaction tube 1 with a breathable tube plug; then load all the coating reaction tubes 1 into a rotatable horizontal vacuum reaction tank 50 in sequence, close the horizontal vacuum reaction tank 50, and then place it into a horizontal sintering furnace 20. The reaction tank rotating shaft 54 on the horizontal vacuum reaction tank 50 is installed on the rotating shaft support seat 55, and close the furnace door 56 of the horizontal sintering furnace; connect the exhaust pipe 4 and the injection pipe 5 on the horizontal vacuum reaction tank 50 to the corresponding equipment; extract the gas in the horizontal vacuum reaction tank 50 and the coating reaction tube 1 through the exhaust pipe 4 to make the vacuum degree in the coating reaction tube 1 be 0.1 - 10 Kpa; heat the coating reaction tube 1 to 200 °C through the horizontal high-temperature sintering furnace 20, as Figure 10 and Figure 11 shown

[0151] Step 3: Slowly inject reducing gas and / or protective gas into the horizontal vacuum reaction tank 50 and the coating reaction tube 1 using the injection pipe 5, keep heating continuously, and slowly increase the temperature; at the same time, extract the excess gas in the horizontal vacuum reaction tank 50 and the coating reaction tube 1 through the exhaust pipe 4, and synchronously keep the vacuum degree in the horizontal vacuum reaction tank 50 always equal to 1 atmospheric pressure; when the temperature rises to 550 °C and the metal surface oxide of the auxiliary welding metal is completely reduced, close the injection pipe 5.

[0152] Step 4: Extract the gas in the horizontal vacuum reaction tank 50 and the coating reaction tube 1 through the exhaust pipe 4 to make the vacuum degree in the coating reaction tube 1 be 0.1 - 5 Kpa; keep the vacuum degree stable, heat the coating reaction tube 1 to 1100 °C according to the heating curve to melt the coating alloy. When heating up, synchronously rotate the horizontal drive vacuum reaction tank 50 in a reciprocating manner in the clockwise and counterclockwise directions; keep warm for 25 - 30 minutes to make the coating alloy and the surface of the ceramic particles undergo a composite reaction; after the reaction is completed, cool down to room temperature to obtain four groups of surface-metallized alumina ceramic particles, and load them into airtight anti-oxidation bags or coat them with anti-oxidation isolation agents for standby respectively.

[0153] In the above preparation method, if the horizontal vacuum reaction tank 50 is relatively small, the gold-ceramic mixture 2 can be directly loaded into the horizontal vacuum reaction tank 50 to prepare surface-metallized ceramic particles.

[0154] Taking the wear-resistant round tube based on the above surface-metallized ceramic particles as an example, this embodiment introduces its preparation process. The outer diameter of the wear-resistant round tube is 3 meters in length, and the thickness of the wear-resistant layer is 25 mm. The thickness of the steel outer tube is 5 mm, the thickness of the inner tube is 2 mm, and the alumina ceramic in the wear-resistant layer accounts for 52% of the volume ratio. Its preparation process is as follows:

[0155] Step [1]: Make a forming cavity and a pressing mold (such asFigure 12 as shown

[0156] Fabricating the forming cavity: The forming cavity includes a first outer tube 751 and a first inner tube 752. The first outer tube 751 is a steel straight tube with a wall thickness of 5 mm and an outer diameter of and a length of 3 meters. The first inner tube 752 is a steel straight tube with a wall thickness of 2 mm and an outer diameter less than and a length of 3 meters. The first inner tube 752 and the first outer tube 751 are sleeved together, and the tube openings at the same end of the two are flanged and welded for sealing. After loading the gold-ceramic mixture 6 at the other end, it is flanged and welded to form a sealed cavity shell 7. Then, holes are drilled at the flanged welding position, and an exhaust pipe 10 with an overflow bin 13 is welded and installed to form a sealed forming cavity. At the same time, an isolation net is installed at the interface between the exhaust pipe 10 and the cavity shell 7. In addition, the inner side of the first outer tube 751 and the outer side of the first inner tube 752 of the forming cavity need to be cleaned.

[0157] Fabricating the pressing die: Fabricating a rotary precessional tube expanding and pressing die set, which includes a rotary precessional tube expanding and pressing fixed die 51, a tube expanding and pressing rotary moving die 52, and a tube expanding press wheel 53.

[0158] Step [2], preparing a uniformly mixed gold-ceramic mixture 6 according to the proportional requirements, and then loading the gold-ceramic mixture 6 into the forming cavity.

[0159] The gold-ceramic mixture 6 in this embodiment is composed of gold-ceramic particles, metal materials, and brazing metals with a volume ratio of 5:3:2. Among them, the gold-ceramic particles are surface-metallized ceramic particles prepared by the aforementioned method. Those with a particle size of 5.8 - 6 mm account for 10% of the volume ratio, those with a particle size of 1.8 - 2 mm account for 45% of the volume ratio, those with a particle size of 0.8 - 1 mm account for 40% of the volume ratio, and those with a particle size of 0.3 - 0.5 mm account for 5% of the volume ratio. The metal material uses Q235 steel particles that have been annealed and softened, with a particle size of 1.5 - 2 mm. The brazing metal is a copper alloy (powder).

[0160] The above gold-ceramic mixture 6 is loaded into the forming cavity from the opening position of the forming cavity. During the loading process, it is vibrated, tamped, or mechanically pressed while loading to make the gold-ceramic mixture 6 densely fill the forming cavity. Then, the tube openings at one end of the first inner tube 752 and the first outer tube 751 are flanged and welded together using secondary welding to completely seal the forming cavity. At the other end, holes are drilled and an exhaust pipe 10 with an overflow bin 13 is welded and installed to form a sealed forming cavity.

[0161] Step [3], starting gas control and heating

[0162] Replace the gas, extract the gas in the forming cavity through the exhaust pipe 10 until the vacuum degree in the forming cavity reaches 0.2 to 0.1 atmospheric pressure, and then stop pumping; fill the forming cavity with reducing gas and protective gas until it reaches 0.8 to 1 atmospheric pressure.

[0163] Place the forming cavity into the heating furnace 14 and heat it up by means of segmented heating and segmented pressurization until the set maximum temperature of 1100 °C is reached and then keep it warm to make the temperature inside and outside the forming cavity uniform. During the heating-up period, keep the vacuum degree in the forming cavity always equal to 1 atmospheric pressure. Seal the exhaust pipe 10, and then place the forming cavity that has reached the preset maximum temperature into the rotary precession pipe expanding and sizing fixed die 51, the pipe expanding and sizing rotary moving die 52, and the pipe expanding pressure wheel 53 for pressure sizing to obtain a semi-finished wear-resistant round pipe.

[0164] During pressure sizing, the overflow bin 13 should always be in communication with the inside of the forming cavity, and keep the overflow bin 13 warm to ensure the smooth discharge of excess materials. During the sizing process, cool it first from the place far away from the opening of the overflow bin 13 to control the cooling rate and prevent deformation or cracks caused by thermal stress.

[0165] Step [4], post-treatment

[0166] According to the preset process requirements and the post-treatment method of Example 1, finally obtain a copper-titanium composite alumina ceramic wear-resistant round pipe.

[0167] The above method is also applicable to the preparation of wear-resistant bushings, equipment lining pipes, etc.

[0168] Example 6

[0169] This example provides a method for preparing surface-metallized ceramic particles, including the following steps:

[0170] Step 1, prepare four combinations of coated alloy and ceramic particles, namely: the volume ratio of the coated alloy to 3.5 - 4 mm ceramic particles is 0.6:9.4; the volume ratio of the coated alloy to 1.8 - 2.2 mm ceramic particles is 0.75:9.25; the volume ratio of the coated alloy to 1 - 1.2 mm ceramic particles is 1.05:8.95; the volume ratio of the coated alloy to 0.3 - 0.5 mm ceramic particles is 1.5:8.5; wherein, the ceramic particles are alumina particles; the coated alloy is an active metal, a secondary welding metal, and a fusing metal with a mass ratio of 25:72:3; the active metal is titanium (powder), the secondary welding metal is copper particles, and the fusing metal is a copper-titanium alloy containing 20% titanium.

[0171] Mix the above four combinations evenly, and according to the methods of steps 2, 3, and 4 in Example 5, prepare four groups of surface-metallized alumina ceramic particles, and respectively put them into airtight anti-oxidation bags or coat them with anti-oxidation isolating agents for use.

[0172] In this embodiment, taking the wear-resistant impeller based on the above-mentioned surface-metallized alumina ceramic particles as an example, its preparation method is introduced. The impeller is a metal composite alumina ceramic wear-resistant impeller for a slurry pump, with a diameter of The thickness of the wheel plate is 300 mm, the thickness of the front and rear impeller plates is 30 mm each, and the wall thickness of the steel sealing forming cavity is 1 mm. In the wear-resistant layer of the wear-resistant impeller, alumina ceramic accounts for 45% of the volume ratio. The blades are made of reinforced materials, and alumina accounts for 50% - 62% of the volume ratio. The specific preparation process of the wear-resistant impeller is as follows:

[0173] Step [1], fabricate the forming cavity and the pressing mold (as shown in Figure 13 , Figure 14 , Figure 15 )

[0174] Fabricate the forming cavity: The forming cavity includes a front plate outer shell 765, a rear plate outer shell 761, a front plate inner shell 764, a rear plate inner shell 762 and five blade shells 763, and is welded together using 1-mm-thick steel sheets, as shown in Figure 14 , to form a circular member with a diameter of . The thickness of the wheel plate is greater than 300 mm, and the thickness of the front and rear impeller plates is greater than 30 mm.

[0175] Weld the rotating shaft connecting piece 65 to the rear plate outer shell 761. Each blade shell 763 is secondarily welded to the front plate inner shell 764 and the rear plate inner shell 762 respectively. Finally, weld the front plate outer shell 765 to the front plate inner shell 764, and the rear plate outer shell 761 and the rear plate inner shell 762 together correspondingly to form the cavity shell 7. Then, weld the exhaust pipe 10 with the overflow bin 13 on the front plate outer shell 765 to form the cavity cover 8 (as shown in Figure 13 ), install the isolation net 9 at the interface of the exhaust pipe 10, and the inner side of the forming cavity needs to be cleaned or copper-plated.

[0176] Fabricate the pressing mold: Fabricate the cavity pressure type movable mold 62 and the cavity pressure type fixed mold 61 with the cavity pressure type center press mold 63 to obtain the finally shaped forming mold.

[0177] Step [2], prepare the uniformly mixed gold-ceramic mixture 6 according to the proportion requirements, and then load the gold-ceramic mixture 6 into the forming cavity.

[0178] The gold-ceramic mixture 6 in this embodiment includes two types, ingredient A and ingredient B. Ingredient A is a gold-ceramic particle, a metal material, and a brazing metal with a volume ratio of 4.5:3.3:2.2; among them, the gold-ceramic particle is the surface-metallized alumina ceramic particle prepared by the aforementioned method, and the particle size is 1 - 1.2 mm; the metal material is selected as Q235 steel particles with surface copper plating after annealing and softening treatment, and the particle size is 1 - 1.3 mm; the brazing metal is copper (particles and powder).

[0179] The ingredient B (enhanced type) is a gold-ceramic particle, a metal material, and a brazing metal with a volume ratio of 6.2:0.8:3; among them, the gold-ceramic particle is a surface-metallized alumina ceramic particle with a size of 3.5 - 4 mm, 1.8 - 2.2 mm, and 0.3 - 0.5 mm prepared by the aforementioned method, and the volume ratio of the three is 65%:27%:8%; the metal material is Q235 steel particles with a surface copper plating and annealed and softened, and the particle size is 1 - 1.3 mm; the brazing metal is copper (particles and powder).

[0180] Load ingredient A into the cavities formed by the rear plate outer shell 761 and the rear plate inner shell 762 of the molding cavity, and the cavities formed by the front plate inner shell 764 and the front plate outer shell 765 respectively; at the same time, load ingredient B into the cavity of each vane shell 763. During the loading process, vibrate, tamp, or machine-press while loading, so that the gold-ceramic mixture 6 can be densely loaded into the corresponding cavities. After filling, seal the cavity shell 7 and the cavity cover 8 to form the molding cavity. In addition, it is also necessary to fill the holes surrounded by the ring 64 between the vanes of the impeller with the shape-preserving sand 66; the compression ratio of the shape-preserving sand 66 is similar to that of the gold-ceramic mixture 6 in ingredient B to ensure that the manufactured wear-resistant impeller does not deform.

[0181] Step [3], Start gas control and heating

[0182] Replace the gas, extract the gas in the molding cavity through the exhaust pipe 10 until the vacuum degree in the molding cavity reaches 0.1 - 0.2 atmospheres, then stop pumping; fill the molding cavity with reducing gas and protective gas until it reaches 0.8 - 1 atmosphere.

[0183] Place the molding cavity into the heating furnace 14 to heat up. During the heating-up period, keep the air pressure in the molding cavity equal to 1 atmosphere; continue to heat to the set maximum temperature of 1100 °C; control the heating to keep the temperature at 1100 °C so that the internal and external temperatures of the molding cavity 7 are uniform. Seal the exhaust pipe 10, and then place the molding cavity that has reached the preset maximum temperature into the cavity pressure fixed mold 61, the cavity pressure movable mold 62, and the cavity pressure center pressure mold 63 for pressure shaping to obtain a semi-finished wear-resistant impeller.

[0184] Step [4], Post-treatment

[0185] According to the preset process requirements and the post-treatment method of Example 1, obtain the finished wear-resistant impeller.

[0186] The above preparation method is also applicable to the preparation of wear-resistant slurry pump volute linings, wear-resistant axial flow pump impellers, and wear-resistant axial flow pump shell linings.

[0187] Example Seven

[0188] This example provides a preparation method for surface-metallized ceramic particles, including the following steps:

[0189] Step 1: Prepare the cladding alloy and ceramic particles with a volume ratio of 0.85:9.15; among them, the ceramic particles are alumina particles with a particle size of 1.2 - 1.5 mm; the cladding alloy includes an active metal, a secondary welding metal, and a fusing metal with a mass ratio of 25:70:5; the active metal is titanium (powder), the secondary welding metal is copper (powder), and the fusing metal is a copper-titanium alloy containing 20% titanium.

[0190] Steps 2, 3, and 4 are the same as the corresponding steps in Example 2, and in this way, the surface-metallized alumina ceramic particles are obtained and are put into an airtight anti-oxidation bag or coated with an anti-oxidation isolation agent for later use.

[0191] Taking the wear-resistant lining based on the above-mentioned surface-metallized alumina ceramic particles as an example, its preparation method is introduced. This wear-resistant lining is a circular copper-titanium-aluminum composite alumina ceramic wear-resistant lining for industrial equipment, with an outer diameter of a length of 1 meter, a composite wear-resistant layer thickness of 20 mm, a steel outer pipe thickness of 5 mm, an inner pipe thickness of 2 mm, and the alumina ceramic in the wear-resistant layer accounting for 48% by volume. The specific preparation method includes the following steps:

[0192] Step 【1】: Manufacture the forming cavity and the pressing mold

[0193] Manufacture the forming cavity: The forming cavity is composed of a second outer pipe 772 and a second inner pipe 771. Among them, the second outer pipe 772 is made of a Q235 steel straight pipe with a wall thickness of 5 mm and an outer diameter greater than a length of 1 meter; the second inner pipe 771 is made of a Q235 steel straight pipe with a wall thickness of 2 mm and an outer diameter of ; the specific manufacturing process is the same as that in Example 5 and will not be elaborated here.

[0194] Manufacture the pressing mold: Manufacture a spinning dynamic mold 71 with a spinning roller 73 and a spinning inner support fixed mold 72, as shown in Figure 16 and Figure 17 shown.

[0195] Step 【2】: Prepare a uniformly mixed gold-ceramic mixture 6 according to the proportional requirements, and then put the gold-ceramic mixture 6 into the forming cavity.

[0196] The gold-ceramic mixture 6 in this example is a gold-ceramic particle, a metal material, and a brazing metal with a volume ratio of 4.5:3:2.5. Among them, the gold-ceramic particles are the surface-metallized alumina ceramic particles prepared by the aforementioned method; the metal material is selected as Q235 steel particles that have been annealed and softened and have a copper plating on the surface, with a particle size of 1 - 1.2 mm; the brazing metal is aluminum alloy (particles).

[0197] Load the above-mentioned gold-ceramic mixture 6 into the forming cavity from the position of the opening of the forming cavity. During the loading process, vibrate, tamp, or mechanically press while loading, so that the gold-ceramic mixture 6 can be densely filled in the forming cavity. After filling, seal the forming cavity in the same manner as in step [2] of Embodiment 5.

[0198] Step [3], Start gas control and heating

[0199] Replace the gas, extract the gas in the forming cavity through the exhaust pipe 10 until the vacuum degree in the forming cavity reaches 0.1 to 0.2 atmospheres, then stop pumping; fill the forming cavity with a protective gas until it reaches 0.8 to 1 atmosphere.

[0200] Place the forming cavity into the heating furnace 14 to heat up. During the heating-up period, keep the air pressure in the forming cavity equal to 1 atmosphere; continue heating to the set maximum temperature of 900 °C; adjust the heating to keep the temperature at 900 °C so that the temperature inside and outside the forming cavity is uniform. During the heating-up to the set maximum temperature, a segmented heating and segmented pressurization method is adopted.

[0201] Seal the exhaust pipe 10, and then place the forming cavity that has reached the preset maximum temperature into the pressing die formed by the spinning moving die 71, the spinning inner support fixed die 72, and the spinning roller 73 for pressing and shaping to obtain a semi-finished product of the wear-resistant lining.

[0202] Step [4], Post-treatment

[0203] According to the preset process requirements, obtain the finished product of the wear-resistant lining according to the post-treatment method of Embodiment 1. This wear-resistant lining is applicable to grinding barrels, mixer casings, sand washing machine casings, and pneumatic dryers.

[0204] Embodiment 8

[0205] This embodiment provides a method for preparing surface-metallized ceramic particles, including the following steps:

[0206] Step 1, Prepare a coating alloy and ceramic particles with a volume ratio of 0.65:9.35; among them, the ceramic particles are alumina ceramic particles with a particle size of 3.5 to 4 mm; the coating alloy is an active metal and a secondary welding metal with a mass ratio of 25:75; the active metal is titanium (powder); the secondary welding metal is copper (powder).

[0207] Steps 2, 3, and 4 are the same as the corresponding steps in Embodiment 2, so as to obtain surface-metallized alumina ceramic particles, and pack them into a sealed anti-oxidation bag or coat them with an anti-oxidation isolation agent for later use.

[0208] Taking the wear-resistant counter-roller sleeve based on the above-mentioned surface-metallized alumina ceramic particles as an example, this embodiment introduces its preparation method. The counter-roller sleeve is an anti-slip counter-roller sleeve in which a steel material and a gold-ceramic mixture are mutually inlaid. The copper-titanium composite alumina ceramic wear-resistant counter-roller sleeve prepared in this embodiment is for industrial grinding rollers, and its outer diameter is 1.5 meters in length, and the thickness of the composite wear-resistant layer is 60 mm. The thicknesses of the inner and outer sleeves of the steel forming cavity are both 5 mm, and the alumina ceramic in the wear-resistant layer accounts for 45% of the volume ratio. The specific preparation method includes the following steps:

[0209] Step [1], making the forming cavity and the pressing die

[0210] Making the forming cavity: The forming cavity is a sealed forming cavity made of Q235 steel, including an outer sleeve 781, an inner sleeve 782, and multiple layers of inlaid corrugated steel bars 783. The corrugated steel bars 783 are used to enhance the strength and wear resistance of the wear-resistant counter-roller sleeve, as Figure 18 , Figure 19 , Figure 20 shown.

[0211] In this embodiment, the outer sleeve 781 is a Q235 steel straight pipe with an outer diameter greater than 5 mm in thickness and 1.5 meters in length; the inner sleeve 782 is a Q235 steel straight pipe with an inner diameter less than 5 mm in thickness and 1.5 meters in length. The corrugated steel bars (as Figure 20 shown) are steel bars with a rectangular cross-section or with rounded or chamfered corners, and the surface is copper-plated, and are made into shapes such as sine wave shape, triangular wave shape, trapezoidal wave shape, etc., for enhancing the structural strength of the wear-resistant counter-roller sleeve.

[0212] During assembly, the first layer of corrugated steel bars 783 is installed on the inner sleeve 782 by multi-point welding, and a designed distance is evenly left between adjacent two corrugated steel bars 783. The second layer of corrugated steel bars 783 is spot-welded on the first layer of corrugated steel bars, and is staggered from the first layer of corrugated steel bars by half a wavelength. According to this method, the remaining layers are installed in turn, and at least two layers of corrugated steel bars 783 are installed.

[0213] Sealing the forming cavity shell: After the corrugated steel bars 783 are installed on the inner sleeve 782, the outer sleeve 781 is sleeved on it, and the same process as in Step [1] of Embodiment 5 is used to heat and flangeweld the pipe orifices at the same end of the inner sleeve 782 and the outer sleeve 781 to make a cavity shell. And at the other end, after loading the gold-ceramic mixture 6, it is flangewelded and sealed to form a cavity shell 7, and then holes are drilled at the flangewelded place, and an exhaust pipe 10 with an overflow bin 13 is welded and installed to make a sealed forming cavity. Similarly, the inner side of the outer sleeve 781 and the outer side of the inner sleeve 782 need to be cleaned or electroplated.

[0214] Manufacturing the pressing die: Manufacture a composite die set. The composite die set uses a forming die set formed by an outer shrinkage pipe pressing die 83 and an inner expansion pipe pressing die 81. The outer shrinkage pipe pressing die 83 positions and presses inward on the forming cavity; the expansion rollers 82 on the inner expansion pipe pressing die 81 rotate and press from the inside outwards. Figure 18 as shown.

[0215] Step [2]: Prepare a uniformly mixed gold-ceramic mixture 6 according to the proportional requirements, and then load the gold-ceramic mixture 6 into the forming cavity.

[0216] The gold-ceramic mixture 6 in this embodiment is a gold-ceramic particle, a metal material, and a brazing metal with a volume ratio of 4.5:3.5:2; among them, the gold-ceramic particle is the surface-metallized ceramic particle prepared by the aforementioned method; the metal material is selected as chromium 12 steel particles with a mass ratio of 60% and a particle size of 2 - 2.2 mm and copper-plated on the surface, and Q235 steel particles with a mass ratio of 40% and a particle size of 1.2 - 1.5 mm and copper-plated on the surface. The metal particles need to be annealed and softened. The brazing metal is a copper alloy (powder or particle).

[0217] Load the above gold-ceramic mixture 6 into the forming cavity from the opening position of the forming cavity. During the loading process, vibrate, tamp, or machine-press while loading, so that the gold-ceramic mixture 6 can be densely filled in the forming cavity. After filling, turn and weld the flanges of the inner sleeve 782 and the outer sleeve 781 together by secondary welding to completely seal the forming cavity, and drill and weld an exhaust pipe 10 with an overflow bin 13 at one end.

[0218] Step [3]: Start gas control and heating

[0219] Replace the gas, extract the gas in the forming cavity through the exhaust pipe 10 until the vacuum degree in the forming cavity reaches 0.1 - 0.2 atmospheres, then stop pumping; fill the forming cavity with a reducing gas and a protective gas until it reaches 0.8 - 1 atmosphere.

[0220] Place the forming cavity in a heating furnace 14 and heat it up. During the heating-up period, keep the air pressure in the forming cavity equal to 1 atmosphere; continue heating to the set maximum temperature of 1100 °C; regulate the heating to keep the temperature at 1100 °C so that the temperature inside and outside the forming cavity is uniformly consistent. During the heating-up to the set maximum temperature, a segmented heating and segmented pressurization method is adopted.

[0221] Seal the exhaust pipe 10, and then place the forming cavity that has reached the preset maximum temperature in a two-way pressurization die set formed by the inner expansion pipe pressing die 81 and the outer shrinkage pipe pressing die 83, and perform outer shrinkage pipe pressurization and inner rotation expansion pipe pressurization to finally press and shape to obtain a semi-finished wear-resistant pair roller sleeve.

[0222] Step [4]: Post-treatment

[0223] According to the preset process requirements and the post-treatment method of the first embodiment, an anti-slip counter-roller sleeve product in which a steel material and a gold-ceramic mixture are mutually inlaid is obtained. This counter-roller sleeve is applicable to wear-resistant counter-roller sleeves and grinding roller sleeves of various vertical mills, Raymond mills, various counter-roller machines, and pressure roller machines.

[0224] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A method for preparing surface-metallized ceramic particles, characterized in that, It includes the following steps: Step 1: Prepare a cladding alloy and ceramic particles with a volume ratio of 0.5 - 1.5:8.5 - 9.5; the cladding alloy includes an active metal, a co-soldering metal, and a fusing metal with a mass ratio of 15 - 40:60 - 80:0 - 10; the active metal is at least one of titanium, titanium alloy, titanium hydride, zirconium, and chromium; the co-soldering metal is at least one of copper, copper alloy, nickel, and boron; the fusing metal is an alloy containing copper and titanium with a melting point lower than 1000°C; the ceramic particles are at least one of alumina, zirconia, silicon carbide, silicon nitride, sialon, titanium carbide-reinforced alumina, titanium carbide-reinforced silicon carbide, titanium carbide-reinforced silicon nitride, and silicon carbide-reinforced alumina, and the particle size of the ceramic particles is 0.3 - 6 mm; Step 2: After mixing the ceramic particles and the cladding alloy, load them into a cladding reaction tube, close the cladding reaction tube or place the cladding reaction tube in a closed system, and extract the gas inside the cladding reaction tube through an extraction pipe to make its vacuum degree 0.1 Kpa - 10 Kpa, and then heat the cladding reaction tube to 200°C - 300°C; Step 3: Inject a reducing gas and / or a protective gas into the cladding reaction tube through an injection pipe, while slowly heating up and extracting the excess gas inside the cladding reaction tube, so that the vacuum degree inside the cladding reaction tube is always equal to one atmospheric pressure until it is heated up to 300°C - 700°C. After the metal surface oxides in the co-soldering metal and the fusing metal are reduced, close the injection pipe; Step 4: Extract the gas inside the cladding reaction tube through an extraction pipe, keep its internal vacuum degree at 0.1 Kpa - 5 Kpa, and then heat it to 900°C - 1250°C, keep it warm for 15 - 60 minutes and then cool it down to room temperature to obtain surface-metallized ceramic particles.

2. The preparation method of the surface-metallized ceramic particles according to claim 1, characterized in that: In step 1, the content of titanium metal in the cladding alloy is 18% - 30%.

3. The preparation method of the surface-metallized ceramic particles according to claim 1, characterized in that: Step 2 is specifically that after mixing the ceramic particles and the cladding alloy, load them into a cladding reaction tube, close the cladding reaction tube, and place it in a high-temperature sintering furnace. Extract the gas inside the cladding reaction tube through an extraction pipe to make its vacuum degree 0.1 Kpa - 10 Kpa, and then heat the cladding reaction tube to 200°C - 300°C through the high-temperature sintering furnace.

4. The preparation method of the surface-metallized ceramic particles according to claim 1, characterized in that: Step 2 is specifically that after mixing the ceramic particles and the cladding alloy, load them into a cladding reaction tube, then place the cladding reaction tube in a vacuum sintering furnace, close the vacuum sintering furnace, extract the gas inside the vacuum sintering furnace through an extraction pipe to make the vacuum degree inside the cladding reaction tube 0.1 Kpa - 10 Kpa, and then heat it to 200°C - 300°C through the vacuum sintering furnace.

5. The preparation method of the surface-metallized ceramic particles according to claim 1, characterized in that: Step 2 specifically includes: mixing ceramic particles with the coating alloy, loading them into a coating reaction tube, then placing the coating reaction tube into a vacuum reaction tank, sealing the vacuum reaction tank, and then placing the vacuum reaction tank into a high-temperature sintering furnace. The gas in the vacuum reaction tank is pumped out through a suction pipe to make the vacuum degree in the coating reaction tube be 0.1 Kpa to 10 Kpa, and then it is heated to 200°C to 300°C by the high-temperature sintering furnace.

6. The method for preparing surface metallized ceramic particles according to claim 1, wherein: Step 2 specifically includes: mixing ceramic particles with the coating alloy, loading them into a coating reaction tube, sealing the coating reaction tube with a tube plug having breathable micropores, and placing it into a vacuum reaction tank with a rotating function, sealing the vacuum reaction tank, and then placing the vacuum reaction tank into a high-temperature sintering furnace. The gas in the vacuum reaction tank is pumped out through a suction pipe to make the vacuum degree in the coating reaction tube be 0.1 Kpa to 10 Kpa, and then it is heated to 200°C to 300°C by the high-temperature sintering furnace.

7. A preparation method of a surface-metallized ceramic wear-resistant fitting, characterized in that, It includes the following steps: Step [1]: According to the shape and size of the wear-resistant fitting, a forming cavity and a pressing mold used in cooperation with the forming cavity are made; the shape of the forming cavity is adapted to the shape of the wear-resistant fitting, and the volume is larger than the volume of the wear-resistant fitting; the pressing mold is used to press the forming cavity from the outside to the inside to make its inner cavity shrink. Step [2]: Prepare a gold-ceramic mixture, load it into the forming cavity, and seal the forming cavity after it is full. The gold-ceramic mixture includes gold-ceramic particles, a metal material, and a brazing metal with a volume ratio of 3.5 - 5.5: 1.5 - 5: 1 - 3; the gold-ceramic particles are surface metallized ceramic particles, or the gold-ceramic particles include clean ceramic particles and surface metallized ceramic particles with a volume ratio of 0 - 0.8: 9.2 - 10; the surface metallized ceramic particles are prepared by the method for preparing surface metallized ceramic particles according to any one of claims 1 to 6; the clean ceramic particles are selected from at least one of alumina, silicon carbide, silicon nitride, sialon, and boron carbide, and the particle size of the clean ceramic particles is 0.08 mm to 0.3 mm; the metal material is metal particles and / or metal powder, wherein the metal particles are at least one of carbon steel alloy, stainless steel, manganese steel alloy, chromium steel alloy, and nickel steel alloy, and have been annealed and softened, and the metal particles are particles with a particle size of 0.5 mm to 2.5 mm and / or metal wires with a diameter of 0.3 mm to 1 mm and a length of 1.5 mm to 3 mm; the metal powder is a metal, metal alloy, or reducible metal oxide powder with a melting point higher than the highest temperature for making the wear-resistant fitting; the brazing metal is at least one of copper, copper alloy, aluminum, aluminum alloy, and boron. Step [3]: Adjust the vacuum degree in the forming cavity, place it in a high-temperature furnace and heat it to a preset temperature, and press and shape the forming cavity through the pressing mold to obtain a semi-finished wear-resistant fitting; the preset temperature is 20 - 200°C above the material with the highest melting point among the brazing metal or the coating alloy of the gold-ceramic particles in Step [2]. Step 【4】: Heat-treat, cut, weld, and trim the semi-finished wear-resistant fittings in sequence according to the preset process requirements to obtain the surface-metallized ceramic wear-resistant fittings.

8. The preparation method of the surface-metallized ceramic wear-resistant fittings according to claim 7, characterized in that: In step 【2】, when local enhancement of the wear-resistant fittings is required, a reinforced gold-ceramic mixture needs to be separately prepared. The reinforced gold-ceramic mixture includes gold-ceramic particles, metal materials, and brazing metals with a volume ratio of 5.2 - 6.2: 0 - 1.5: 3 - 3.

8.

9. The preparation method of the surface metallized ceramic wear-resistant fitting according to claim 7 or 8, characterized in that Step 【3】 is specifically as follows: 3.

1. Extract the gas in the forming cavity through the exhaust pipe until the vacuum degree reaches 0.05 - 0.2 atmospheres, then stop pumping; fill the forming cavity with reducing gas and / or protective gas until the vacuum degree is equal to 1 atmosphere. 3.

2. Heat the forming cavity to the preset temperature by a high-temperature furnace and then keep it warm so that the temperatures inside and outside the forming cavity are the same. During the heating and heat preservation periods, keep the air pressure in the forming cavity equal to 1 atmosphere. 3.

3. Seal the exhaust pipe, place the forming cavity that has reached the preset temperature into a pressing mold for pressure shaping to obtain the semi-finished wear-resistant fittings.

10. The preparation method of the surface-metallized ceramic wear-resistant fittings according to claim 9, characterized in that In step 【1】, the forming cavity includes a cavity shell and a cavity cover connected to the cavity shell; The exhaust pipe is arranged on the cavity shell or the cavity cover, and a separation net is installed at the interface between the exhaust pipe and the cavity shell or the cavity cover; Alternatively, the exhaust pipe is arranged on the cavity shell or the cavity cover, and an overflow bin is connected to the exhaust pipe. The overflow bin communicates with the forming cavity through the exhaust pipe and is used to collect excess materials; a separation net is installed at the entrance of the overflow bin; In step 3.2, the high-temperature furnace adopts a method of segmented heating and segmented pressurization during the heating process; In step 3.3, during the pressure shaping process, the overflow bin is always in communication with the forming cavity and the overflow bin is kept warm; at the same time, the forming cavity is cooled first from the end far away from the overflow bin through a temperature control system, and the cooling rate is controlled to prevent deformation or cracks caused by thermal stress.

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