Study On Process Of Ni Coating On Ceramic Surface By Chemical Vapour Deposition

Ceramics-metallisation composite is the material integrating of ceramic and metal as awhole, possesses not only plasticity and tenacity of metal but also excellent physical andchemical properties (such as high-wearing feature, high temperature resistance, etc.) ofceramic, balances the properties of metal and ceramic, overcomes or complements theweakness, and becomes the advanced composite applied in situations with high temperature,abrasion, corrosion, and oxidation; however, the wettability between metal and ceramic ispoorer, which restrains its properties and preparation significantly. The purpose of the study isto prepare a layer of Ni coating on the surface of ceramic and carry out the modificationtreatment on the surface of ceramic to improve the wettability between metal and ceramic.Metallization process on the surface of Al2O3ceramic was carried out by chemical vapordeposition technique. The reaction precursor NiCl26H2O could be converted into metal nickelwith the experience of being dried and H2reduction treatment, and a metal nickel coating onthe surface of Al2O3ceramic was obtained. And investigates the influences of technologicalparameters (hydrogen flow, argon flow, deposition temperature, heat preservation period, etc.)on Ni coating; the study is to prepare Al2O3foamed ceramic/steel matrix composites withpressure-less infiltration method and investigate the incorporation on its interface.The study results show that when deposition temperature is1200℃, hydrogen flow is150ml/min, argon flow is200ml/min, and heat preservation period is60min, the depositionrate on Al2O3ceramic sample is the maximum, the main component of coating is Ni, and thebinding power between coating and substrate is sound, and could reach the thickness of40μm; Ni coating can improve the wettability between metal and ceramic to a great extent anddecrease the wetting angle between Al2O3ceramic and copper from138°to30.15°; moltensteel not only closely integrates with macro pore wall of foamed ceramic, but also infiltratesinto and fills triangle micropore in the center of foamed ceramic framework reinforced hole,forming bicontinuous structures between steel substrate and foamed ceramic framework, and external wall and internal wall of reinforced hole; the bicontinuous structures improves thebinding power on the composite surface.