CN-121975374-A - Anti-sticking coating for sintering, preparation method and sintering tray

Abstract

The invention discloses an anti-sticking coating for sintering, a preparation method and a burning-resistant disc, wherein the anti-sticking coating for sintering uses TiN or TiC as an anti-sticking material, mgO is used as a shell forming agent, a TiO 2 oxide film formed on the surface of the MgO and the TiN or TiC forms a magnesium titanate (MgTiO 3 ) ceramic phase through solid-solid diffusion reaction, and the magnesium titanate ceramic phase is connected with coarse TiN or TiC particles after high-temperature sintering to form a relatively hard TiN or TiC shell, so that the anti-friction performance, the scratch resistance performance and the service life of the coating are improved. The sintering disc coated with the anti-sticking paint for sintering has no defects of peeling, cracking and the like on the surface of the coating after sintering, the coating is kept complete, has good and stable blocking effect, and solves the problems that impurities are easy to introduce into the existing anti-sticking paint for sintering, the anti-sticking paint reacts with sintered alloy at high temperature, the performance of a sintered product is deteriorated and the like.

Inventors

• LI SHENG
• CHEN XINXIN
• CHEN XINZHE
• LIU GANG
• LI PENG
• SU ZHENHUA
• Cao Hangfu
• LI HAO
• LIU JIAWEI
• WU LE

Assignees

• 株洲欧科亿切削工具有限公司

Dates

Publication Date

20260505

Application Date

20260209

Claims (10)

1. 1. The anti-sticking coating for sintering is characterized in that raw materials comprise TiN and/or TiC, mgO, a film forming agent, a defoaming agent, a dispersing agent and a solvent, wherein the particle size of the TiN or TiC is 100-325 meshes, the content of the TiN or TiC is 100-200 g in each liter of solvent, the particle size of the MgO is 0.1-1.0 mu m, and the content of the MgO is 0.5-2.5% of the mass of the TiN and/or TiC.
2. 2. The anti-sticking coating for sintering according to claim 1, wherein the film forming agent comprises one or more of hydroxyethyl cellulose, acacia, guar gum and polyethylene glycol, and the content of the film forming agent is 3-15 g/L solvent.
3. 3. The anti-sticking coating for sintering according to claim 1, wherein the antifoaming agent is one or more of n-butanol, n-octanol, methanol and ethanol, and the content of the antifoaming agent is 0-5 g/L of solvent.
4. 4. The anti-sticking coating for sintering according to claim 1, wherein the dispersing agent is tween 80 or polyethylene glycol, and the content of the dispersing agent is 15-25 g per liter of solvent.
5. 5. The anti-sticking coating for sintering according to claim 1, wherein the preparation method comprises the steps of adding a film forming agent, a defoaming agent and a dispersing agent into water, uniformly mixing, adding TiN and/or TiC and MgO, uniformly dispersing to obtain slurry, and grinding and mixing the slurry to obtain the anti-sticking coating for sintering.
6. 6. The anti-sticking coating for sintering according to claim 5, wherein YG6 hard alloy grinding balls with the diameter of 10mm are adopted for grinding, the ball-to-material ratio is 2-8:1, and the grinding time is 0.5-2h.
7. 7. A setter plate characterized by comprising a material tray and the anti-sticking coating for sintering according to any one of claims 1-6 coated on the surface of the material tray.
8. 8. The setter plate as claimed in claim 7, wherein the preparing step includes spraying the anti-sticking coating for sintering onto the tray, then placing the tray in an oven at 150-250 ℃ for drying for 3 hours, and evaporating the moisture-curable coating to obtain the setter plate.
9. 9. The setter plate of claim 7, wherein the coating thickness is 0.05-0.2 mm.
10. 10. The setter plate of claim 7, wherein the setter plate is used in sintering cemented carbide or cermet at a sintering temperature of less than or equal to 1550 ℃.

Description

Anti-sticking coating for sintering, preparation method and sintering tray Technical Field The invention relates to the technical field of sintering coating, in particular to an anti-sticking coating for sintering, a preparation method and a sintering tray. Background Cemented carbide is a metallic material with high hardness, high strength, wear resistance and corrosion resistance. The ceramic metal is characterized by high-temperature resistance, corrosion resistance, high strength at high temperature, small density, easy processing, corrosion resistance, good thermal conductivity and the like, and is widely used for cutting tools and wear-resistant parts. The hard alloy and the metal ceramic are mainly produced by adopting a powder metallurgy method, sintering is one of the key steps, and the sintering process determines the final performance of the hard alloy and directly influences the application effect of the hard alloy. Sintering temperatures typically exceed 1400 ℃, so the setter plates typically use high temperature resistant and low cost graphite. However, the hard alloy and the metal ceramic material have strong affinity with carbon element, and a layer of barrier material is generally required to be coated between the product and the setter plate, so that the direct contact between the sintered product and graphite is avoided, and the barrier material has the main functions that: (1) Preventing chemical reaction, namely preventing metal components (such as tungsten W, titanium Ti, cobalt Co and the like) in the alloy from chemically reacting with the graphite setter plate at high temperature, and causing the alloy components to change or the graphite disc to be damaged. (2) Physical adhesion is avoided, namely, in the sintering process, particularly, the high-binding phase alloy can be softened due to high temperature, and the high-binding phase alloy is physically adhered to a graphite burning-bearing plate, so that the surface quality of a finished product is damaged, and the burning-bearing plate is damaged. (3) The method improves the yield, prevents the alloy from directly contacting with the sintering tray, obviously reduces the defects of bending, deformation, carburization removal and the like of the product, ensures that the sintered alloy has uniform tissue structure and physical property, avoids the possible uneven local components or structural defects caused by contact and reaction with the sintering tray, obviously improves the yield and reduces the economic loss in the production process. (4) The service life of the burning bearing plate is prolonged, the paint not only protects the hard alloy, but also protects the burning bearing plate, the service life of the burning bearing plate can be prolonged, and the replacement frequency and the cost are reduced. Thus, providing a coating that can have good stability at high temperatures is an important factor in improving the sintering quality. The existing commonly used carbon coating is burnt out in the sintering process of the product, loses adhesion with the surface of a graphite material disc, is quite easy to fall off, and therefore cannot be reused generally, and the coating needs to be recoated after being used once, so that labor intensity and cost are increased. And the polluted sintering furnace is easy to adhere to the product when the product is unloaded. Sulfur impurities introduced into carbon black used in carbon coatings can react with the product to form sulfides, deteriorating the product performance and appearance. In addition, in the presence of carbon, the stability of the oxides of the anti-sticking component in the coating is poor, for example, al 2O3 can be reduced by graphite, and Al element diffuses into the alloy, deteriorating the surface quality and the intrinsic performance of the alloy. In order to improve the stability of a coating and the coating isolation effect formed by the coating, a hard alloy sintering anti-sticking coating, a preparation method and application thereof are disclosed in CN118206887A, wherein raw materials comprise graphite materials, carbon black, silicate minerals, a dispersion medium and a solvent, the silicate minerals contain more than 50wt% of one-dimensional structure silicate, the one-dimensional structure silicate is adopted as an inorganic additive, the filament structure of the one-dimensional structure silicate can not only endow the one-dimensional structure silicate with thickening performance, the stability of the coating is improved on the premise of reducing or avoiding the use of an organic thickener, but also the film forming performance of the coating is improved, and meanwhile, the silicon carbide whiskers can also generate submicron silicon carbide whiskers and aluminum oxide and silicon dioxide particles in situ in the high-temperature sintering process, wherein the silicon carbide whiskers can play the roles of supporting and film binders, the direct reactio