Laser Heating of a Steel-based Metal Matrix Composite: Influence of Laser Pulse Parameters and Particle Number Density on Meltpool Size
S.Z. Shuja, B.S. Yilbas and H. Ali
Laser melting of steel based metal matrix composite composes of steel St 316 and St 4130 with 15% WC carbide particles is considered and the meltpool size, due to variation of laser pulse parameter and the number density of WC particles, is simulated. Laser pulse parameter is introduced to modify the laser pulse intensity distribution at the irradiated surface; in which case, increasing laser pulse parameter results in the laser peak intensity shift from the irradiated spot centre towards the irradiated spot edge. An experiment was carried out to validate the predictions of particle distribution in the irradiated region. It is found that predictions of the particle distribution in the resolidified meltpool agree well with the experimental data. Increasing laser pulse parameter lowers the maximum temperature significantly in the meltpool and modifies the meltpool geometry and reduces the meltpool size. Increasing the number density of WC particles lowers slightly the maximum temperature and the depth of the meltpool, which is attributed to the high melting temperature of WC particles as they remain in the solid phase in the meltpool.
Keywords: CO2 laser, tungsten carbide (WC), steel, particles, laser heating, laser pulse parameters, mathematical model, finite element method (FEM), melting, particle distribution