Numerical modelling of the laser surface processing of magnesia partially stabilized zirconia by the means of three-dimensional transient finite element analysis

A numerical technique has been employed to use the ABAQUS finite element analysis (FEA) package in order to simulate the CO₂ laser surface processing of a magnesia partially stabilized zirconia (MgO-PSZ) bioinert ceramic. The transient FEA takes into account the heat radiation, heat convection and phase change during the laser processing. The heat source has been modelled as a stepwise moving laser source with small steps in the scanning direction to approximate continuous movement. It further extends and validates numerical methods by comparing experimental data of surface temperature for laser surface processing of the MgO-PSZ to the solution from the FEA model. Experiments involving CO₂ laser surface melting of the MgO-PSZ were also carried out using various laser process parameters, and the measured melt width and depth of laser-treated tracks were used to evaluate the validity of the models. In order to prevent the crack formation in the laser processing, pre- and post-heating were proposed by using the scanning of laser beam with the lower power before and after laser processing with high power to lower the thermal gradient.