Plasma Spraying Nickel-based Coating And The Application Inagricultural Tools

With the rapid development of agricultural technology and continuousimprovement of mechanization and automation, agricultural machinery is more andmore brought to the attention of the countries during the process of realizing theagricultural modernization. So how to solve the problem of agricultural machineryfailure caused by the wear is particularly urgent.TiC nickel-based composite coating was prepared by plasma spraying technology.the repair of the IS195rotary blade. Analyze the influence of different TiC content onthe microstructure and properties of the coating.Further optimize the technologicalparameters of plasma spraying.Obtaine the process specification which can guide thepractical production. Practices prove that the coating is feasible to repaire IS195rotary blade.Adopt orthogonal test analysis to determine the optimum parameters of plasmaspraying: spraying current is650A; spraying distance is110mm; the main air flow is63.7L/min; the auxiliary air flow is27.3L/min；the powder feeding speed is10.5g/min;the gun moving speed is100mm/s.Nickel-based coating has the typical layered wave structure.The coating combineswith substrate mechanically.Some pores exist in the coating.The microhardness nearthe surface is biggest,up to570HV. wear mechanism is abrasive wear and adhesivewear.Electrochemical corrosion test proves that, nickel-based coating has a bettercorrosion resistance than substrate.Add different content of TiC powder（10%，15%，20%）to Ni powder to prepareTiC nickel-based composite coating. The TiC nickel-based composite coatingcombines with substrate mechanically. With the increasing of the content of TiC, TiCparticles distribute more evenly in the coating. When the content of TiC is20%, themicrohardness of coating is highest and the the wear mechanism is abrasive wear.When the content of TiC is15%, the friction coefficient of coating is low to0.35andthe friction performance is best,whose wear mechanism is abrasive wear and adhesivewear. Electrochemical corrosion polarization curve proves that, the corrosionresistance of TiC nickel-based composite coating is better than Nickel-based coating.After argon arc remelting treatment,Ni60+15%TiC composite coating combines with the sunstrate metallurgically, the binding surface elements between coating andsubstrate diffuse and black border disappears. The microstructure is composed of γ-Ni, TiC,Cr23C6and CrB.The average microhardness increases and the frictioncoefficient reduces. The surface is bright and clean,on which there existing slightscratches. The wear mechanism is abrasive wear. Electrochemical corrosion test provesthat, the corrosion potential rises and corrosion resistance increases.Apply Ni60+15%TiC composite coating with a low cost and high quality to therepair of IS195rotary blade. The field simulation test proves that, the wear loss ofrotary blade after surface treatment reduces significantly. The grinding crack is offand on, the grinding width and depth is smaller and shows the excellent abrasionresistance.