Preparation method of ceramic mold side plate and ceramic mold

Abstract

The invention belongs to the technical field of ceramic molds, and discloses a preparation method of a side plate of a ceramic mold and the ceramic mold, the preparation method of the side plate of the ceramic mold comprises the following steps: obtaining a side plate substrate, and forming a to-be-sprayed surface at a preset position of the side plate substrate; the first powder is sprayed to the to-be-sprayed face through cold spraying, and a metal transition layer is formed; and the second powder is sprayed on the metal transition layer to form a wear-resistant coating, and the ceramic mold side plate is obtained. Compared with a traditional process of embedding hard alloy into a side plate mold, the preparation method of the ceramic mold side plate has the advantages that the working procedures of substrate groove milling, hard alloy gluing, hard alloy brazing, coarse grinding after high-temperature deformation, hard alloy coarse grinding and the like are reduced, on the premise that the wear resistance is met, the technological process can be effectively reduced, material and manpower waste is reduced, and the production cost is reduced. The energy-saving and environment-friendly effects are achieved; meanwhile, the wear-resistant coating formed through the method is thinner, and after the wear-resistant coating loses efficacy, the wear-resistant coating can be sprayed again to be repaired.

Description

Technical Field

[0001] This invention belongs to the field of ceramic mold technology, and specifically relates to a method for preparing a ceramic mold side plate and a ceramic mold. Background Technology

[0002] Ceramic molds are key equipment in the ceramic industry chain, characterized by "small batches, multiple types, and easy wear and tear," and are considered special consumables with a high degree of personalization. Ceramic molds are mainly used for ceramic powder molding. Molds are divided into upper molds, lower molds, and concave molds. Some products with holes may require mandrels. Side plates are lining plates inside the mold cavity and come into contact with the powder during pressing, generating friction.

[0003] The wear resistance of the ceramic mold side plates determines the service life of the assembly, while the ease of material discharge determines the overall quality of the assembly. This requires the ceramic mold side plates to possess high hardness and a low coefficient of friction. Due to the high hardness of ceramic particles, the working parts of the mold are prone to wear failure; generally, a wear of about 200μm necessitates replacement. To improve mold life and product consistency, cemented carbide (such as tungsten steel) is typically used for the working parts of ceramic molds. Currently, the main method is to embed cemented carbide blocks, but this approach suffers from problems such as long process flows and significant waste of materials and manpower.

[0004] To improve the wear resistance of ceramic mold side plates, mold manufacturers have carried out a rather complex process for the side plates. The most crucial process is to inlay a carbide strip on the inside of the side plate, and then use a grinding machine to rough grind and finish it to the final size. However, this process is quite complicated. Summary of the Invention

[0005] The present invention aims to improve at least one technical problem in the prior art.

[0006] The first aspect of this invention provides a method for preparing a ceramic mold side plate, comprising the following steps: Obtain a side panel substrate and form a surface to be coated at a predetermined position on the side panel substrate; The first powder is sprayed onto the surface to be coated by cold spraying to form a metal transition layer; The second powder is sprayed onto the metal transition layer to form a wear-resistant coating, thus obtaining the ceramic mold side plate; The first powder includes metal powder; The second powder comprises metal carbides and transition metals in a mass ratio of 1:(0.01-0.1).

[0007] Furthermore, the metal powder includes at least one of aluminum powder, copper powder, nickel powder, aluminum alloy powder, copper alloy powder, nickel alloy powder, and nickel-clad aluminum powder.

[0008] Furthermore, the metal carbide includes at least one of tungsten carbide, titanium carbide, tantalum carbide, niobium carbide, molybdenum carbide, and hafnium carbide; the transition metal includes at least one of iron, cobalt, and nickel.

[0009] Furthermore, the first powder also includes hard particle powder, and the mass ratio of the metal powder to the hard particle powder is 1:(0.1-0.3), wherein the hard particle powder includes at least one of Al2O3, SiC and cemented carbide powder.

[0010] Furthermore, the average particle size of the metal powder is 15μm-45μm, and the average particle size of the hard particle powder is 1μm-20μm.

[0011] Furthermore, the thickness of the transition metal layer is 60μm-120μm, and the thickness of the wear-resistant coating is 100µm-300µm.

[0012] Furthermore, the working gas for cold spraying is nitrogen or helium, the working gas pressure is 2.5 MPa-3.0 MPa, the working gas temperature is 350℃-650℃, the distance between the cold spraying gun and the surface to be sprayed is 18mm-30mm, and the travel speed of the spray gun is 80mm / s-200mm / s.

[0013] Furthermore, the second powder is applied using plasma spraying or supersonic flame spraying.

[0014] Furthermore, when the second powder is sprayed using the plasma spraying method, the spraying power of the plasma spraying is 20kW-50kW, and the spraying distance of the plasma spraying is 80mm-120mm. When the second powder is sprayed using the supersonic flame spraying method, the propane pressure in the supersonic flame spraying is 0.6 MPa-0.7 MPa, the propane flow rate is 70 L / min-88 L / min, the oxygen pressure in the supersonic flame spraying is 1 MPa-1.5 MPa, the oxygen flow rate is 280 L / min-300 L / min, and the spraying distance of the supersonic flame spraying is 120 mm-160 mm.

[0015] A second aspect of the present invention provides a ceramic mold comprising a ceramic mold side plate prepared by the above-described method for preparing a ceramic mold side plate.

[0016] The beneficial effects of this invention are as follows: Compared with the traditional side plate mold inlay cemented carbide process, the method for preparing the ceramic mold side plate of this invention reduces the steps of substrate milling, cemented carbide bonding, cemented carbide brazing, rough grinding after high temperature deformation, and rough grinding of cemented carbide. Under the premise of meeting wear resistance performance, this invention can effectively reduce the process flow, reduce material and labor waste, and play a role in energy conservation and environmental protection. At the same time, the wear-resistant coating formed by the method of this invention is thinner, and the wear-resistant coating can be re-sprayed for repair after failure. Attached Figure Description

[0017] Figure 1 A schematic diagram of the structure of a ceramic mold side plate prepared by a traditional ceramic mold side plate manufacturing process; Figure 2 This is a schematic diagram of the structure of the ceramic mold side plate prepared in Example 1; Figure 3 This is a schematic diagram of the test surface; Figure 4 The results of wear-scratch tests on WC-10Co cemented carbide wear-resistant coating and WC-10Co cemented carbide sintered alloy at different locations are shown. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0019] The traditional ceramic mold side plate preparation process includes the following steps: (1) Cutting 45# steel plate to the side plate outline size; (2) Milling: rough milling the side plate outline; (3) Milling groove: rough milling the groove; (4) Gluing: glue the carbide strip into the groove; (5) Brazing: braze the glued ends (brazing high temperature can easily cause material deformation); (6) Grinding: rough grinding the bottom reference surface of the side plate; (7) Rough grinding: rough grinding the carbide strip to form a stepped cross-section; (8) Fine grinding: fine grinding the stepped cross-section to the final shape and position size to obtain the ceramic mold side plate.

[0020] A schematic diagram of the structure of the ceramic mold side plate prepared by the traditional ceramic mold side plate manufacturing process is shown below. Figure 1 As shown ( Figure 1 (1-Hard alloy strip).

[0021] It is evident that the traditional process of preparing wear-resistant ceramic mold side plates by embedding cemented carbide strips is complex. Therefore, it is necessary to improve the traditional preparation method.

[0022] This invention provides a method for preparing a ceramic mold side plate, comprising the following steps: Obtain a side panel substrate and form a surface to be coated at a predetermined position on the side panel substrate; The first powder is sprayed onto the surface to be coated by cold spraying to form a metal transition layer; The second powder is sprayed onto the metal transition layer to form a wear-resistant coating, thus obtaining the ceramic mold side plate; The first powder includes metal powder; The second powder comprises metal carbides and transition metals in a mass ratio of 1:(0.01-0.1).

[0023] In the method for preparing the ceramic mold side plate provided in this application, after obtaining the side plate substrate, a surface to be sprayed is formed at a preset position to provide a flat substrate for the formation of subsequent coatings (metal transition layer and wear-resistant coating), ensuring that the subsequent coating can stably adhere to the key wear-resistant area of ​​the mold side plate. Then, cold spraying is used to spray the first powder onto the surface to be sprayed to form a metal transition layer. The core advantage of the cold spraying process is that it can prepare a metal transition layer with low porosity (<1%) and high adhesion (>30MPa), which can effectively connect the side plate substrate and the subsequently formed wear-resistant coating, providing reliable support for the dense formation and firm adhesion of the wear-resistant coating, and solving the potential problem of poor adhesion between the coating and the substrate in traditional processes. In this application, the second powder is composed of metal carbide and transition metal in a mass ratio of 1:(0.01-0.1). The metal carbide has excellent wear resistance and is the core component ensuring the wear resistance effect of the coating, while the transition metal can optimize the fusion effect between powder particles, further improving the density and structural stability of the wear-resistant coating.

[0024] Compared to the traditional process of embedding cemented carbide in side plate molds, this application eliminates the cumbersome steps of substrate milling, cemented carbide bonding, cemented carbide brazing, rough grinding after high-temperature deformation, and rough grinding of cemented carbide, significantly reducing machining time and saving labor costs. It also avoids the waste of raw materials caused by milling and rough grinding in traditional processes, thus contributing to energy conservation and environmental protection. In traditional processes, the cemented carbide blocks are thick and require scrapping after only a small amount of wear, and are prone to cracking due to impact and compression. This application, however, only requires spraying a thin wear-resistant coating to meet the requirements, and the coating can be repaired by re-spraying after failure, significantly reducing usage and maintenance costs. Furthermore, traditional processes only embed cemented carbide wear-resistant blocks (cemented carbide strips) locally on the side of the side plate, leaving the end faces and other areas untreated for wear resistance. This method, however, can flexibly form a wear-resistant coating on multiple key areas such as the side and end faces of the side plate, expanding the wear-resistant coverage and effectively extending the overall service life of the ceramic mold side plate.

[0025] Specifically, in this embodiment, obtaining the side plate substrate and forming a surface to be coated at a preset position on the side plate substrate includes: first, cutting 45# steel plate to the side plate outline size according to the mold side plate drawing; then, rough milling the side plate outline to obtain the side plate substrate; and then rough grinding the side plate substrate to form a stepped cross-section, which is the surface to be coated.

[0026] In some embodiments, the metal powder includes at least one of aluminum powder, copper powder, nickel powder, aluminum alloy powder, copper alloy powder, nickel alloy powder, and nickel-clad aluminum powder.

[0027] In some embodiments, the metal carbide includes at least one of tungsten carbide, titanium carbide, tantalum carbide, niobium carbide, molybdenum carbide, and hafnium carbide; the transition metal includes at least one of iron, cobalt, and nickel.

[0028] In some embodiments, the first powder further includes hard particle powder, wherein the mass ratio of the metal powder to the hard particle powder is 1:(0.1-0.3), and the hard particle powder includes at least one of Al2O3, SiC, and cemented carbide powder.

[0029] This application achieves higher adhesion of the wear-resistant coating by further adding a specific proportion of hard particle powder to the first powder, which in turn strengthens the soft metal powder and facilitates the formation of a high-density wear-resistant coating.

[0030] In some embodiments, the average particle size of the metal powder is 15μm-45μm, and the average particle size of the hard particle powder is 1μm-20μm.

[0031] In some embodiments, the thickness of the transition metal layer is 60μm-120μm, and the thickness of the wear-resistant coating is 100µm-300µm.

[0032] The traditional process of inserting cemented carbide into side plate molds uses cemented carbide blocks with a thickness of 4mm. These blocks are scrapped and replaced when they wear down to about 200μm. Furthermore, the cemented carbide blocks are prone to cracking due to collisions and compression. In contrast, this application only requires spraying a wear-resistant coating with a thickness of 100µm-300µm to meet the usage requirements.

[0033] In some embodiments, the working gas for cold spraying is nitrogen or helium, the working gas pressure is 2.5 MPa-3.0 MPa, the working gas temperature is 350℃-650℃, the distance between the cold spraying gun and the surface to be sprayed is 18mm-30mm, and the travel speed of the spray gun is 80mm / s-200mm / s.

[0034] In some embodiments, the second powder is applied using plasma spraying or supersonic flame spraying.

[0035] In some embodiments, when the second powder is sprayed using plasma spraying, the spraying power of the plasma spraying is 20kW-50kW, and the spraying distance of the plasma spraying is 80mm-120mm. When the second powder is sprayed using the supersonic flame spraying method, the propane pressure in the supersonic flame spraying is 0.6 MPa-0.7 MPa, the propane flow rate is 70 L / min-88 L / min, the oxygen pressure in the supersonic flame spraying is 1.0 MPa-1.5 MPa, the oxygen flow rate is 280 L / min-300 L / min, and the spraying distance of the supersonic flame spraying is 120 mm-160 mm.

[0036] Plasma spraying utilizes the flame of a plasma arc to heat and spray a second powder, bringing it to a molten or highly plastic state. Under the traction of the high-speed flame, the powder impacts and deposits onto the surface of the metal transition layer, forming a wear-resistant coating.

[0037] Supersonic flame spraying utilizes propane as fuel, which, when combined with high-pressure oxygen in a combustion chamber, generates a high-temperature, high-speed combustion flame. This flame axially feeds the powder particles into the flame, heating them to a molten or semi-molten state and accelerating them to speeds of 300-500 m / s or even higher, thereby obtaining a wear-resistant coating with high bonding strength and high density.

[0038] In some embodiments, the surface to be coated is pretreated before the metal transition layer is formed on the surface to be coated. The pretreatment includes the following steps: cleaning the surface to be coated with acid or sandblasting the surface to be coated.

[0039] Using acid solutions (such as HCl solution or H2SO4 solution) to clean or sandblast the surface to be sprayed removes oxide film, oil, and other contaminants, and roughens the surface, thereby improving the adhesion between the metal transition layer and the surface to be sprayed.

[0040] This invention also provides a ceramic mold, which includes a ceramic mold side plate prepared by the above-described method for preparing ceramic mold side plates.

[0041] The ceramic mold of this application includes not only ceramic mold side plates, but also upper mold, lower mold, and concave mold, etc. The upper mold, lower mold, and concave mold are the same as those in the prior art. The difference between the ceramic mold of this application and the existing ceramic mold is that the side plates are made by the above-mentioned method for preparing ceramic mold side plates.

[0042] The technical solution of the present invention will be described below with reference to specific embodiments.

[0043] Example 1 A method for preparing a side plate of a ceramic mold includes the following steps: Obtain the side panel substrate, grind one side of the side panel substrate flat, and roughly grind the corresponding other side to create a stepped cross-section, which is the surface to be sprayed. Sandblast the surface to be sprayed. Aluminum-coated nickel powder (Ni5Al) is sprayed onto the surface to be coated by cold spraying (the average particle size of the aluminum-coated nickel powder is 25μm, the working gas for cold spraying is nitrogen, the nitrogen pressure is 3.0MPa, the nitrogen temperature is 650℃, the distance between the cold spraying gun and the surface to be coated is 20mm, and the travel speed of the spray gun is 100mm / s), forming a metal transition layer with a thickness of 80μm. WC-10Co cemented carbide powder (with a WC to Co mass ratio of 1:0.1) was sprayed onto a metal transition layer using supersonic flame spraying (the average particle size of the WC-10Co cemented carbide powder was 15μm, the propane pressure in the supersonic flame spraying was 0.65MPa, the propane flow rate was 80L / min, the oxygen pressure in the supersonic flame spraying was 1.2MPa, the oxygen flow rate was 290L / min, and the spraying distance in the supersonic flame spraying was 140mm), forming a wear-resistant coating with a thickness of 200μm (the end face and side face of the side plate substrate were both formed during the spraying process), thus obtaining the ceramic mold side plate.

[0044] A schematic diagram of the structure of the ceramic mold side plate prepared in Example 1 is shown below. Figure 2 As shown ( Figure 2 In the middle: 2-side plate substrate; 21-wear-resistant coating), wear-resistant coating is formed on both the end face and the side face of the side plate substrate.

[0045] Performance testing Ceramic mold side plates were prepared using three different sizes of side plate substrates according to the method in Example 1, and were respectively denoted as ceramic mold side plate 1, ceramic mold side plate 2 and ceramic mold side plate 3.

[0046] The wear-resistant coatings on the inner side of ceramic mold side plate 1, the outer side of ceramic mold side plate 2, and the end face of ceramic mold side plate 3, as well as the surface of commercially available WC-10Co hard sintered alloy (purchased from Zhuzhou Cemented Carbide Group Co., Ltd.), were subjected to friction and wear performance tests and hardness tests. A schematic diagram of the test surfaces is shown below. Figure 3 As shown ( Figure 3 In the table: 2-side plate substrate; 21-wear-resistant coating; 211-inner wear-resistant coating; 212-outer wear-resistant coating; 213-end face wear-resistant coating); In the friction and wear performance test, the material of the mating ball is ZrO2, and the contact surface pressure is greater than 20MPa, consistent with the pressure conditions experienced during ceramic tile pressing. The test results and hardness after 20 minutes of wear are shown in Table 1. Figure 4 As shown ( Figure 4 The 1 in the figure refers to the ceramic mold side plate 1; Figure 4 2 in the figure refers to the ceramic mold side plate 2; Figure 4 The number 3 in the figure refers to the ceramic mold side plate 3; Figure 4 4 in the text is commercially available WC-10Co hard sintered alloy.

[0047] Table 1 Wear test results from Figure 4 As shown in Table 1, the wear track width and depth of the WC-10Co cemented carbide wear-resistant coating and the WC-10Co cemented carbide sintered alloy at different locations are similar, making them difficult to test with macroscopic instruments. The hardness value of the WC-10Co cemented carbide wear-resistant coating at different locations is slightly lower than that of the WC-10Co cemented carbide sintered alloy, but their wear resistance is similar or even better. Hardness value is only one indicator of wear resistance; to improve the wear resistance of the coating, a coating material with a higher hardness value can be selected.

[0048] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a side plate of a ceramic mold, characterized in that, Includes the following steps: Obtain a side panel substrate and form a surface to be coated at a predetermined position on the side panel substrate; The first powder is sprayed onto the surface to be coated by cold spraying to form a metal transition layer; The second powder is sprayed onto the metal transition layer to form a wear-resistant coating, thus obtaining the ceramic mold side plate; The first powder includes metal powder; The second powder comprises metal carbides and transition metals in a mass ratio of 1:(0.01-0.1).

2. The method for preparing the ceramic mold side plate according to claim 1, characterized in that, The metal powder includes at least one of aluminum powder, copper powder, nickel powder, aluminum alloy powder, copper alloy powder, nickel alloy powder, and nickel-clad aluminum powder.

3. The method for preparing the ceramic mold side plate according to claim 1, characterized in that, The metal carbide includes at least one of tungsten carbide, titanium carbide, tantalum carbide, niobium carbide, molybdenum carbide, and hafnium carbide; the transition metal includes at least one of iron, cobalt, and nickel.

4. The method for preparing the ceramic mold side plate according to claim 1, characterized in that, The first powder also includes hard particle powder, and the mass ratio of the metal powder to the hard particle powder is 1:(0.1-0.3). The hard particle powder includes at least one of Al2O3, SiC and cemented carbide powder.

5. The method for preparing the ceramic mold side plate according to claim 4, characterized in that, The average particle size of the metal powder is 15μm-45μm, and the average particle size of the hard particle powder is 1μm-20μm.

6. The method for preparing the ceramic mold side plate according to claim 1, characterized in that, The thickness of the transition metal layer is 60μm-120μm, and the thickness of the wear-resistant coating is 100µm-300µm.

7. The method for preparing the ceramic mold side plate according to claim 1, characterized in that, The working gas for cold spraying is nitrogen or helium, the working gas pressure is 2.5 MPa-3.0 MPa, the working gas temperature is 350℃-650℃, the distance between the cold spraying gun and the surface to be sprayed is 18mm-30mm, and the travel speed of the spray gun is 80mm / s-200mm / s.

8. The method for preparing the ceramic mold side plate according to claim 1, characterized in that, The second powder is applied by plasma spraying or supersonic flame spraying.

9. The method for preparing the ceramic mold side plate according to claim 8, characterized in that, When the second powder is sprayed using plasma spraying, the spraying power of plasma spraying is 20kW-50kW, and the spraying distance of plasma spraying is 80mm-120mm. When the second powder is sprayed using the supersonic flame spraying method, the propane pressure in the supersonic flame spraying is 0.6 MPa-0.7 MPa, the propane flow rate is 70 L / min-88 L / min, the oxygen pressure in the supersonic flame spraying is 1 MPa-1.5 MPa, the oxygen flow rate is 280 L / min-300 L / min, and the spraying distance of the supersonic flame spraying is 120 mm-160 mm.

10. A ceramic mold, characterized in that, This includes ceramic mold side plates prepared by the method described in any one of claims 1-9.

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