Laser Surface Modification

Abstract

Laser surface modification is used to change the surface composition, microstructure, or geometry of a material to give it certain desired properties. There are six major forms of laser surface modification. These are: laser surface heat treatment; laser surface melting; laser direct metal deposition; laser physical vapor deposition; laser shock peening; and laser surface texturing. In laser surface heat treatment, no melting takes place, while in laser surface melting, a thin surface layer of the workpiece is melted, and as a result of the rapid quenching, may form new structures which are harder. In laser deposition, a second material is applied to the surface and melted by the laser beam either to alloy with a thin surface layer of the base material or to bond to the surface. Laser shock peening, however, generates shock waves which induce compressive residual stresses on the surface of the material.