CN-118272750-B - Chromium oxide-based coating and preparation method and application thereof

Abstract

The invention discloses a chromium oxide-based coating and a preparation method and application thereof. The preparation method of the chromium oxide-based coating comprises the following steps of 1) dispersing ceramic particles or/and metal particles, chromium oxide particles and a binder in water, wherein the particle size of the ceramic particles and the metal particles is smaller than that of the chromium oxide particles, and then performing spray drying to obtain composite particles, and 2) thermally spraying the composite particles on the surface of a substrate to obtain the chromium oxide-based coating. The chromium oxide-based coating has higher hardness and excellent toughness, shows excellent friction and wear resistance, can be used as a wear-resistant coating on the surface of a metal part, and is suitable for large-scale industrial application.

Inventors

• HUANG JIBO
• SHI KAI
• ZENG DECHANG
• QIU ZHAOGUO

Assignees

• 华南理工大学

Dates

Publication Date

20260505

Application Date

20240401

Claims (7)

1. 1. A method for preparing a chromium oxide-based coating, comprising the steps of: 1) Dispersing ceramic particles or/and metal particles, chromium oxide particles and a binder in water, wherein the particle size of the ceramic particles and the metal particles is smaller than that of the chromium oxide particles, and then performing spray drying to obtain composite particles; 2) Thermally spraying the composite particles on the surface of a matrix to obtain a chromium oxide-based coating; the ceramic particles in the step 1) are at least one of alumina ceramic particles, titanium oxide ceramic particles, zirconia ceramic particles and yttria-stabilized zirconia ceramic particles; The particle size of the ceramic particles in the step 1) is 0.5-5 mu m; Step 1) the metal particles are spherical Ti particles; the particle size of the metal particles in the step 1) is 0.1-10 mu m; the particle size of the chromium oxide particles in the step 1) is 10-30 mu m; And 1) the mass ratio of the ceramic particles or/and the metal particles to the chromium oxide particles is 1:5-25.
2. 2. The method according to claim 1, wherein the composite particles in step 1) have a particle diameter of 30 μm to 120. Mu.m.
3. 3. The method according to claim 1, wherein the thermal spraying in the step 2) is one of atmospheric plasma spraying, supersonic flame spraying and supersonic cold spraying.
4. 4. The method according to claim 1 or 3, wherein the substrate in step 2) is one of carbon steel, stainless steel and titanium alloy.
5. 5. A chromium oxide-based coating, characterized by being produced by the production method according to any one of claims 1 to 4.
6. 6. The chromium oxide-based coating according to claim 5, wherein the thickness of the chromium oxide-based coating is 200 μm to 300. Mu.m.
7. 7. A metal part, characterized in that the surface is covered with a chromium oxide based coating according to claim 5 or 6.

Description

Chromium oxide-based coating and preparation method and application thereof Technical Field The invention relates to the technical field of thermal spraying, in particular to a chromium oxide-based coating, a preparation method and application thereof. Background Frictional wear is one of the main factors that cause the failure of various metal parts in mechanical equipment in the metallurgical, aerospace, mechanical, petrochemical, mining and agricultural industries, and the like, and therefore reducing the frictional wear of metal parts has an important role in the safety, reliability and economic benefits of mechanical equipment. The ceramic material has the characteristics of high hardness, high mechanical strength, good friction and wear resistance, good chemical stability and the like, and the wear resistance of the metal part can be greatly improved by adopting the surface engineering technology to prepare the ceramic coating on the surface of the metal part. The chromium oxide ceramic has the advantages of high hardness, easy processing, low friction coefficient, high temperature resistance, abrasion resistance, corrosion resistance and the like, and is suitable for serving as a surface abrasion-resistant coating of a mechanical part under a special working condition. Hardness is a key reference index for evaluating the wear resistance of a wear-resistant coating, the hardness of the wear-resistant piece being more than or at least 80% of the hardness of the abrasive, otherwise the wear resistance is necessarily insufficient. Currently, the vickers hardness of a chromium oxide coating prepared by plasma spraying is about 1100HV 0.3～1300HV0.3, whereas the vickers hardness of a chromium oxide coating prepared by supersonic flame spraying is 1000HV 0.3～1200HV0.3, and furthermore, the vickers hardness of a chromium oxide-based coating prepared by other methods (e.g., a composite chromium oxide coating with added alumina or titania) is generally lower than 1300HV 0.3. Toughness is a key performance index for evaluating the fracture resistance of the wear-resistant piece, and has positive effect on relieving the micro-fatigue peeling of the pure wear of the material. However, the chromia ceramic coating has the characteristics of high brittleness and high porosity, especially its high brittleness results in its lower fracture toughness, reducing the wear resistance of the chromia coating. Currently, the cracking resistance of chromium oxide-based ceramic coatings is improved to some extent mainly by mixing aluminum oxide or titanium oxide with metal powder (two or more kinds of powder are directly mixed and then sprayed to obtain a biphase or multiphasic material coating, and different kinds of materials are usually present in the coating in a form of independent blocks) but the hardness of the coating is reduced. The microstructure and structure of the coating are important factors affecting its hardness and fracture toughness. The microstructure of the coating is regulated and controlled through the design of the spray powder material, so that the chromium oxide-based ceramic coating with high hardness and excellent toughness is expected to be obtained, and the method has important significance for improving the friction and wear resistance of the wear-resistant piece. Therefore, it is of great importance to develop a chromium oxide-based coating having both higher hardness and excellent toughness and excellent abrasion resistance. Disclosure of Invention The invention aims to provide a chromium oxide-based coating, and a preparation method and application thereof. The technical scheme adopted by the invention is as follows: The preparation method of the chromium oxide-based coating comprises the following steps: 1) Dispersing ceramic particles or/and metal particles, chromium oxide particles and a binder in water, wherein the particle size of the ceramic particles and the metal particles is smaller than that of the chromium oxide particles, and then performing spray drying to obtain composite particles; 2) And thermally spraying the composite particles on the surface of the matrix to obtain the chromium oxide-based coating. Preferably, the mass ratio of the ceramic particles or/and the metal particles to the chromium oxide particles in the step 1) is 1:5-25. Preferably, the amount of the binder in the step 1) is 8% -12% of the total weight of the ceramic particles or/and the metal particles and the chromium oxide particles. Preferably, the water in the step 1) is 1 to 1.5 times of the total weight of the ceramic particles or/and the metal particles and the chromium oxide particles. Preferably, the particle size of the ceramic particles in the step 1) is 0.1-5 μm. Preferably, the ceramic particles in step 1) are at least one of alumina ceramic particles, titania ceramic particles, zirconia ceramic particles, yttria-stabilized zirconia ceramic particles. Preferably, the ceramic particles of step 1) are s