METHOD FOR ALTERING THE COMPOSITION AND STRUCTURE OF ALUMINUM BEARING OVERLAY ALLOY COATINGS DURING DEPOSITION FROM METALLIC VAPOR

摘要

ABSTRACT OF THE DISCLOSUREThe composition and structure of aluminum bearingoverlay alloy coatings, such as MCrAlY type overlaycoatings, are altered during deposition from a metallicvapor by biasing the substrate at a small negative poten-tial relative to ground while the vapor is at leastpartially ionized. The coating layer deposited undersuch conditions is characterized by substantial freedomfrom leader defects and by a reduced aluminum contentand resultant improved ductility. Such coating condi-tions can be incorporated in a preselected manner intoconventional deposition techniques, such as vacuum vapordeposition and sputtering, to produce a variety of coatingcompositional and structural variations from a singlecoating alloy ingot source.