Diamond for wear and corrosion applications

Diamond is an attractive material for use in many applications where wear or corrosion resistance are important because of its unique combination of mechanical properties (e.g. high hardness and Young's modulus) and chemical inertness. However, the size, cost and difficulty of fabrication of diamond stones and compacts have restricted the use of diamond in many applications. With the recent emergence of CVD diamond coating technology a much larger range of applications is now possible. This paper reviews the tribological and chemical properties of diamond and diamond coatings and discusses the developments which will need to take place if successful diamond coatings are to be produced on engineering components. Although preliminary results have shown that diamond coatings can exhibit excellent wear and corrosion properties, the scale of the deposition technology will need to be increased and the adhesion of the coatings improved on a range of technological substrates if the coatings are to find more widespread industrial use.