Abstract: A method for fusibly bonding a coating material to a metal article includes depositing such coating material in solid form on a surface of the article, substantially simultaneously thermally liquifying the coating material and the surface of the article by focusing a relatively high power continuous wave laser beam thereon, and removing the laser beam therefrom to allow cooling and hardening thereof so as to provide a solidified surface layer with a strong and relatively thin interstitial bond between the layer and the article. An exemplary engine valve with a relatively fine structure of the coating material for increased hardness is disclosed.

Abstract: A method of heat treating a bore in a workpiece to increase its surface hardness is disclosed, including shaping an annular laser beam emanating from a source into an elongated focal pattern to provide a more evenly distributed energy level in cross section, directing the elongated focal pattern generally axially inwardly toward the bore, reflecting the elongated focal pattern from a mirror arrangement substantially transversely upon a surface of the bore to provide an instantaneously more uniformly hot heating zone thereat, and effecting relative motion between the workpiece and the mirror arrangement so that the bore is progressively scannably heat treated to minimize heating of the entire workpiece.