Study On Process & Mechanics Of Surface Transpositional Coating Of Copper On Iron Powder

Coating powder is a new type of powder metallurgy materials with multiphase and composite property. Due to its great varieties and special performance, it has been extensively applied in the industries including national defense industry, mechanical manufacture, and chemical industry etc. In the microscopic view, the coating powder features in multiphase, coated integrality and the characteristics of its various components can be shown according to different need; In the macroscopic view, coating powder is character by its homogeneous property, which realizes uniform metallic phase fabric of products, and meanwhile greatly reduces or eliminates the defects of unstable performance and non-homogeneous components of products caused by non-uniform blending. In addition, the coating powder is able to change surface property of powder and accordingly improve the technical property of powder, and prepare powder metallurgy materials and products of better performance.Converter sludge in Panzhihua Iron and Steel Corp is a kind of gas atomizing powder that is difficult to be processed by traditional pressing-sintering powder metallurgy process because most powder is in the shape of smooth approximate ball, so it has limited application. Consequently, based on the above mentioned reality, this paper focuses on surface coating of copper around iron powder by means of chemical replacement plating, not only realizing surface modification to initial iron powder, but preparing cheaper and higher quality composite powder for powder metallurgy application.This paper analyzes coating sectional microscopic structure, surface topography, and elements in coating by adopting advanced testing methods including XRD, SEM, metallographic, and analytical chemical titration etc. In this paper, it has been researched that the effects of addition agents on coating quality and optimizes processing parameter through orthogonal experiment; through contrast test, the passivation effects of different passivant on copper coating were studied; through kinetic test, the effects of temperature, stirring speed, initial Cu concentration and pH of solution on replacement rate have also been discussed, and diffusion coefficient of Cu2+ was calculated based on above test.The studies show that the effects of selected addition agents (sodium acetate, laurel sodium sulfate, ally theorem, polyethylene glycol) on coating quality are: there is a peak...