Patent ID: 6701882
Filing Date: 2004-03-09
Classification: C23C

Abstract:
A surface coating of the working surface of a cylinder of a combustion engine, having the combination of the following characteristics:the coating is applied by plasma spraying; the surface of the coating comprises a plurality of open pores; the degree of porosity of the surface of the coating amounts to between 0.5 and 10%; the statistic mean pore size amounts to between 1 and 50 &mgr;m, whereby at least nearly exclusively pores with a size of less than 100 &mgr;m are present; the pores are stochastically distributed in the surface of the coating, both as far as the area and the size is concerned; the coating comprises a content of bound oxygen of between 0.5 and 8% by weight; the coating comprises inclusions of FeO and Fe3O4 crystals, serving as solid lubricants; the roughness of the surface of the coating is adjusted by mechanical finishing to an arithmetic mean roughness Ra of between 0.02 and 0.4 &mgr;m and to a mean peak-to-valley distance Rz of between 0.5 and 5 &mgr;m.