Evaluating the impacts of laser process parameters on microstructure and microhardness of H13-TiC composite using the mathematical modelling

Abstract

To achieve an optimum microstructure and hardness of the H13-TiC composite, we aim to optimize and improve the laser process parameters of the composite. In the beginning, TiC particles due to important properties such as high hardness, high modulus, low density and high thermal stability were successfully deposited on the H13 hot work tool steel using a pulse Nd: YAG laser. In the deposition process, laser scanning speeds of 2, 7 and 12 mm/s, pulse widths of 6, 8 and 10 ms and operational distances of 4, 5 and 6 mm were used. Then, the response surface methodology was used to find the relationships between three independent variables, develop a mathematical model, better understand the simultaneous effects of variables on the properties of composite area and achieve the optimal values of these variables. XRD and EDS were used to identify the phases, and FESEM and SEM were applied to evaluate the microstructure. The obtained results demonstrate that optimal conditions for the desirable microstructure on the composite surface are achieved at the scanning speed, pulse width and operational distance of 12 mm/s, 9.96 ms and 5.94 mm, respectively. Therefore, using this condition, the microhardness of 1606.49 Vickers is obtained.