High Temperature Nanocomposite Coatings by Plasma Spraying for Friction and Wear Applications

In conventional high temperature solid lubricants, during thermal cycling, a reduction of lubrication performance results in fluctuating friction coefficient and formation of abrasive wear debris. Moreover, the demand for high temperature solid lubrication in the range 300-1000 °C has led to development of self-lubricating wear resistant coatings of desired characteristics at high temperatures. This chapter introduces typical nanostructured ceramic matrix coatings produced by plasma spraying for self-lubricating wear resistance purposes in a wide temperature range. Production and properties of spray dried agglomerated nanocomposite granules are described and, then, structural, mechanical and tribological properties of Cr2O3-Ag nanocomposite coatings are presented. The lubrication mechanisms at moderate and high temperatures, by means of creation of a silver tribofilm on top surface, is discussed. </jats:p