SURFACE AND INTERFACE ANALYSIS, vol.44, no.7, pp.831-836, 2012 (SCI-Expanded)
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 (c) 2012 John Wiley & Sons, Ltd.