Eigenschaften und Anwendungen von Chemisch Nickel‐Dispersionsschichten

Properties and applications of electroless nickel composite coatings This paper discusses the variety of composite electroless coatings used in different industrial applications. The inclusion of particulate matter within electroless nickel deposits can add entirely new properties to the plated layer. Composites with hard particles like diamond, silicon carbide and boron carbide provide greater wear resistance and the possibility for adjustable friction properties. Composite electroless nickel with diamond or ceramics has found wide applications in the textile, automotive and mechanical engineering industry. Friction joints in automotive engines constitute an important field of application for diamond coatings. Modern internal combustion engine designs require that the crankshaft and camshaft be fitted at a specific relative angle. In order to establish the correct angle during assembly and maintain it over the life of the engine, axial press‐fit joints in combination with centrally located retention bolts are employed. Failure of either the joints or the bolts can result in serious damage to the engine. The torque transfer ability of these engine components can be significantly increased by incorporating a friction foil that is diamond‐coated on both sides. Composite coatings with coarser diamond particles can be used for the coating of precision tools in the semiconductor industry. Enhanced lubricity can be achieved by incorporating solid lubricants in electroless nickel deposits. Composite coatings with PTFE or PFA offers non‐stick surfaces with antiadhesive properties and good resistance against adhesive wear. Because of the temperature and softness limitations these coatings are best suited for lower temperature and light loading applications. Electroless nickel boron nitride coatings can withstand temperatures up to 600 °C. This coating reduces coefficient of friction and wear in dynamic applications. A further application is the coating of molds for rubber and plastic components.