The Effect of Pulsed Laser Parameters on Surface Compositing of H13-TiC

In this study, the laser surface processing of H13 hot-work tool steel was successfully carried out by TiC powder deposited through laser surface engineering process using a pulse Nd:YAG laser. The deposition process has been done at laser scanning speed of 2, 7 and 12 mm/s and pulse width of 6, 8 and 10 ms and operational distance of 4, 5 and 6 mm. Characterization of the composited area was done using field emission scanning electron microscope (FESEM), scanning electron microscope (SEM), X-ray diffraction (XRD) analysis and energy dispersive X-ray spectroscopy (EDX). Hardness of the composited surfaces was measured with a microhardness tester. Through taking advantage of response surface methodology (RSM), the experimental results were fed into Design Expert software which then mutual relationships between three independent variables were established. Prediction of model at the experimental range using systematic data enables us to provide a better understanding of the simultaneous effect of variables on the properties of composed area. Moreover the optimum value of variables was predicted. In order to applying composite surface with optimized microstructure, the optimal condition for scanning speed, pulse width and operational distance is 12 mm/s, 9.96 ms and 5.94 mm respectively and at this term, microhardness is 1606.49 Vickers. Characterization results of optimized samples showed a composited zone without any crack and porosity, with appropriate incorporation and uniform distribution of TiC particles in the matrix.