Applications of Nickel Matrix Composite Coatings

摘要

Several spare parts of the equipment in textile industry should exhibit some special characteristics due to their continue contact with very sensible materials, such as yarns, filaments, clothes. These parts must be very smooth, hard and possess very good wear resistance. In practice, manufacturers use very often hard chromium coated parts, which become useless in short periods of time due to their heavy duty performance and, consequently, must be substituted frequently. In this work, we have tried to substitute the hard chromium coatings by nickel matrix composite coatings, in order to ameliorate the surface aspect and the tribological properties. We have used nickel matrix coatings containing silicon carbide (SiC) micro-particles, prepared under pulse plating conditions. It has been proved that this technique, under very well defined conditions (pulsed current density, frequency, duty cycle, etc), permits us to obtain hard and smooth coatings, even in the absence of organic additives, which show improved tribological properties. As a result of this work, we have substituted certain chromium coated equipment components of the textile industry by these composite coated ones.