Study on the plastic removal behavior of SiC ceramic materials in laser-assisted high-temperature turning

Abstract

In this study, we investigate the mechanisms underlying material removal and address the challenges associated with predicting the material removal rate during laser-assisted high-temperature turning of silicon carbide ceramics. A finite element model is developed to simulate micron-scale material removal under thermo-mechanical coupling during turning, thereby elucidating the differences in removal behavior with and without laser assistance. This analysis informs the refinement of conventional models for material removal rates and supports the development of a predictive mathematical framework for hard and brittle materials experiencing high-temperature softening. The model further enables the computation of the actual material removal rate for SiC when it is in a plastic or near-plastic state. By treating the actual removal rate as the response variable, we employ analyses of variance, residual analysis, three-dimensional response surfaces, and contour maps to evaluate the interactive effects of process parameters-specifically cutting depth, feed rate, rotational speed, and laser power-on the removal rate. Our results indicate that, under specific high-temperature conditions, the inherent hardness and brittleness of SiC are mitigated, transitioning the material removal mechanism from brittle fracture to plastic or near-plastic deformation. Notably, cutting depth and feed rate are identified as the most critical factors, with their interaction exerting a pronounced influence on the removal rate. The prediction error between the estimated and actual values of the removal rate under plastic/near-plastic conditions ranges from 2.06% to 6.92%, thereby underscoring the models accuracy and reliability. Optimally, simultaneously achieving high material removal rates and superior surface quality can be realized by employing larger cutting depths, higher feed rates and laser power, along with lower rotational speeds.