Laser embedding of TiC particles into the surface of phosphor bronze‐bearing material

A carbon film containing 5% TiC particles is formed on a pre‐prepared bronze surface prior to laser treatment. The carbon film provides increased absorption of the incident laser beam and hosts TiC particles with a uniform distribution at the workpiece surface. Optical and scanning electron microscopy are used to examine the metallurgical and morphological changes in the laser treated layer. Micro‐hardness of the laser‐treated surface is measured, and the residual stress formed in the surface vicinity is measured using the X‐ray diffraction technique. It was found that a dense layer with fine grains was formed in the laser‐treated layer. The micro‐hardness of the laser‐treated surface increases almost three times compared with the base material hardness. The presence of a dense layer and the formation of Cu₃N in the surface region contribute to the hardness enhancement at the surface. Copyright © 2012 John Wiley & Sons, Ltd.