Preparation Of Ultrafine Nickel Coated Copper Powders And Research Of Process

The application of ultrafine powder has greatly promoted the newmaterial development, such as the electronic information, aerospace,metallurgy, transportation industry and so on. Along with particles sizedecreases, and granular surface activity increases, it will easily happenreunion and oxidation resistance, and make the particles to reduce losscharacteristics, lose application value. Nickel-coated copper metalpowders have good corrosion resistance and electrical conductivity, itsgrinding performance and carrying capacity can be significantlyimproved; nickel powders with very good electromagnetic shieldingperformance have been widely used in military and civilian industry.But compared with copper, price of pure nickel is high and poorconductivity, so combining copper and nickel can be greatly enhancematerials price and applications. Study the preparation technology ofnickel-coated copper powder has important market value and practicalsignificance.The super fine copper powder was preparated by liquid reduction,then in its surface using electroless plating method coated nickelparticles ,final outcome ultrafine nickel-coated copper compositepowders was formed. Study the preparation technology of nickel-coatedcopper powder, respectively, research particle size, bag wrapped effectand the influence law of dispersion at the initial solution of Cu2+concentration and Ni²⁺concentration, reductive agent, PH , Cu/Niquality ratio, blend modes, ultrasonic power:1. Using two blend modes to raw material: one was the prereductioncopper powder as the matrix, and then on its surface employedelectroless nickel; another making Cu powder and Ni powderrespectively, then mixed two powders in the water. The results showthat Raw material blending modes on nickel-coated copper compositepowder microstructure and coating effects can have an importantimpact, and preparation of nickel-coated copper composite powdersonly have Cu,Ni two-phase;2. In pre-Cu powder for preparation of different sizes coated by nickel was prepared by chemical deposition. the microstructure and component of nickel-coated copper powder was observed by the scanning electronic microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS), Investigated Matrix copper granularity in nickel coated effects. The results show that chemical plating method can prepare the nickel coated copper powder,when Cu powder particle size is smaller , Ni granularity coated effect becomes good , but poor dispersibility;3. In pre-Cu powder for preparation coated by nickel was prepared by chemical deposition , nickel coated copper powder transform rate, coated effect and dispersibility were studied under Cu²⁺ concentration, Ni²⁺ concentration and ultrasonic power, the microstructure and component of nickel-coated copper powder was observed by the scanning electronic microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS)and X-ray diffraction instrument. The results show that chemical plating method can prepare the nickel coated copper powder. In ultrasonic conditions, nickel coated copper compound powder have better dispersivity, Cu,Ni composite powder in content, no significant changes.