Prodn. of hard material layer on substrate

摘要

Prodn. of a hard material layer on a substrate having an electrolytically applied Ni-Cr coating is claimed, in which the hard material layer is deposited in a plasma-promoted physical vacuum deposition process. The novelty is that a Ni layer of thickness of 13-20 mu m and a Cr layer of thickness of 0.2-0.3 mu m and deposited as the Ni-Cr coating on the substrate and heated in a 1st tempering step after rinsing and drying in vacuum until the substrate and components, including the wall of the coating chamber, have a temp. of 75-150 deg C. Water condensates are vaporised from the surfaces. The substrate is heated in a 2nd tempering step to a max. temp. for the base material of the substrate until hydrogen is driven off the surface zone of the electrolytically applied Cr layer. The temp. of the substrate decreases and is maintained below the max. temp of the 2nd tempering step. The substrate is then subjected to ion purification until impurities are removed. A 0.05-1 mu m metal layer is then slowly deposited by plasma-promoted physical vacuum deposition and then a 0.5-2 mu m corrosion-resistant hard material layer is deposited. The temp. of the substrate is raised compared with the temp. on ion purification but below the temp. of the 2nd tempering step. The hard material coating on the substrate is also claimed.