Method for preparing wear-resistant coating on valve metal surface through micro-arc oxidation/hydrothermal treatment

Abstract

A method for preparing a wear-resistant coating on a valve metal surface through micro-arc oxidation / hydrothermal treatment comprises the steps that sodium molybdate and sodium aluminate are added into water to obtain a mixed solution; or sodium molybdate and sodium hydroxide are added into water to obtain a mixed solution; the mixed solution serves as electrolyte, a valve metal sample serves as an anode, and a stainless steel tank serves as a cathode; the valve metal sample is placed in the electrolyte for micro-arc oxidation so as to obtain a molybdenum-containing micro-arc oxidation sample; and the molybdenum-containing micro-arc oxidation sample is added to a hydrothermal reaction kettle for hydrothermal treatment so as to prepare the wear-resistant coating on the surface of the valve metal sample. According to the method for preparing the wear-resistant coating on the valve metal surface through micro-arc oxidation / hydrothermal treatment, by adopting the electrolyte containing sodium molybdate, the micro-arc oxidation coating with a micro-porous structure is formed through micro-arc oxidation, and then the molybdenum disulfide nano-structure layer is formed after hydrothermal treatment, and the coating possesses extremely excellent wear resistance due to adhesion of molybdenum disulfide.

Description

technical field [0001] The invention relates to the technical field of metal surface modification, in particular to a method for preparing a wear-resistant coating by micro-arc oxidation / hydrothermal treatment on the surface of valve metal. Background technique [0002] Aluminum-magnesium-titanium and its alloys have important application value and broad application prospects in the fields of automobiles, electronic communications, aerospace, national defense, and medical equipment due to their low density, high specific strength, and high specific stiffness. Some of its own shortcomings, such as low surface hardness, poor wear resistance, poor corrosion resistance, poor high temperature oxidation resistance, etc., limit its application range in the field of tribology. Friction and wear usually occur on the surface layer. Through reasonable surface strengthening Technology, can effectively improve the anti-friction and wear resistance of the interface surface. Currently com...

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Problems solved by technology

[0002] Aluminum-magnesium-titanium and its alloys have important application value and broad application prospects in the fields of automobiles, electronic communications, aerospace, national defense, and medical equipment due to their low density, high specific strength, and high specific stiffness. Some of its own shortcomings, such as low surface hardness, poor wear resistance, poor corrosion resistance, poor high temperature oxidation resistance, etc., limit its application range in the field of tribology. Friction and wear usually occur on the surface layer. Through reasonable surface strengthening Technology, can effectively improve the anti-friction and wear resistance of the interface surface

Currently commonly used metal surface treatment technologies are generally divided into two categories: (1) Surface alloying methods (ion implantation, carburizing, nitriding or carbonitriding, etc.) and heat treatment (flame quenching, induction hardening, etc.) to improve the chemical properties of metal surfaces Composition and structure, but this kind of technology is mostly applied to ferrous metals such as steel; (2) surface coating method (thermal spraying, physical vapor deposition, chemical vapor deposition, laser cladding, etc.) to prepare anti-friction and wear-resistant coatings on the metal surface , but most of them require a high-temperature atmosphere environment and the operation is complicated. At the same time, there are generally problems such as low bonding force between the coating and the metal, and limited bearing capacity of the substrate, which easily leads to the phenomenon that the coating falls off and fails under non-uniform load.

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