Preparation And Properties Of The Ni Matrix Coatings Synthesized By Electrodeposition

Metal materials play an irreplaceable role in the development of the society as the most widely used engineering materials. Metallic coating is one of the important applications of the metal materials. Lots of parts always work in harsh surroundings in engineering. The parts should have not only outstanding microhardness, strength but also other eminent properties, such as good wear performance, better heat resistance and corrosion behavior. This problem can be solved by covering the parts with a metallic coating with outstanding properties. In this case, working life of the parts can be lengthened. With the development of the technology, it makes increasing requirement for the parts. Therefore, the metallic coating should have corresponding development to meet the requirements. Among the metallic coatings, Ni matrix coatings can adapt to the harsh working atmosphere because of the eminent properties, such as high microhardness, strength and better wear resistance. Therefore, Ni matrix coatings are the most studied coatings. There are lots of methods to synthesize metallic coatings. Such as spray, chemical vapor deposition, sputtering, electrodeposition, etc. However, electrodeposition is the admitted most economic method which is suitable for the industrial production.In this paper, Ni and Ni matrix coatings were synthesized by electrodeposition and the properties of the coatings were studied. (1)Ni-Co alloy coatings were prepared on Cu substrates by electrodeposition and the influence of the electrolyte composition and pH on the magnetic properties was studied. Simultaneously, the electrocrystallization behaviors of the coatings were discussed. (2)Ni-Co films were synthesized by direct current electrodeposition on the ITO glasses, and the influence of the electrolyte composition on the morphology, structure and composition of coatings was studied. Simultaneously, sintering experiment was performed and the influence of the heat treatment temperature on the structure and magnetic properties of the coatings was studied. (3)Ni-Y2O3 composite coatings were synthesized on Cu substrates by electrodeposition. Effects of the incorporated Y2O3 on the structure, morphology, microhardness and tribological properties were discussed. It is found that the incorporated Y2O3 particles apparently changed the morphology and structure of the composite coatings. The composite coatings possess higher microhardness and better tribological property. (4) Ni-Y2O3 composite coatings were prepared by pulse electroplating and the mechanical property of the coatings was studied. It is demonstrated that better mechanical property can be obtained by the application of pulse electroplating. The coatings prepared by pulse electroplating possess better properties than the coatings prepared by direct electroplating.