What is the technology of plasma spraying?

       Information summary: Plasma spraying is a material surface strengthening and surface modification technology, which can make the substrate surface have the properties of wear resistance, corrosion resistance, high temperature oxidation resistance, electrical insulation, heat insulation, radiation protection, wear reduction and sealing. Plasma spraying technology uses a DC-driven plasma arc as a heat source, heats ceramics, alloys, metals and other materials to a molten or semi-molten state, and sprays them onto the pretreated workpiece surface at high speed to form a solid surface layer. .plasma spray is also used in medical

 Plasma spraying is a material surface strengthening and surface modification technology, which can make the substrate surface have the properties of wear resistance, corrosion resistance, high temperature oxidation resistance, electrical insulation, heat insulation, radiation protection, wear reduction and sealing. Plasma spraying technology uses a DC-driven plasma arc as a heat source, heats ceramics, alloys, metals and other materials to a molten or semi-molten state, and sprays them onto the pretreated workpiece surface at high speed to form a solid surface layer. .Plasma spraying is also used for medical purposes. A layer of tens of microns is sprayed on the surface of artificial bone as a method to strengthen artificial bone and enhance its affinity. The parameters of plasma spraying mainly include the composition and flow of working gas, electrical parameters, powder feeding amount, spraying distance and spraying angle, relative moving speed of spray gun and workpiece, etc.

Post-coating treatment.

 

         1. Hole sealing treatment. In order to prevent the corrosion medium from reaching the substrate through the pores of the coating and causing the substrate to corrode, the coating must be sealed. There are many materials used as sealing agents. How to choose a suitable sealing agent should be considered according to various factors such as the working medium, environment, temperature and cost of the workpiece.

 

         2. For workpieces subjected to high stress loads or impact wear, in order to improve the bonding strength of the coating, the spray coating should be remelted (such as flame remelting, induction remelting, laser remelting and hot isostatic pressing, etc.), A coating that is porous and only mechanically bonded to the substrate becomes a dense coating that is metallurgically bonded to the substrate.

 

         3. If there are dimensional accuracy requirements, the coating should be machined. Since the spray coating has different characteristics from general metal and ceramic materials, reasonable processing methods and corresponding process parameters must be selected to ensure the smooth progress of the spray coating machining and the required dimensional accuracy.