Numerical Simulations and Analysis of the Thermal Effects on Silicon Carbide During Ductile Mode Micro-Laser Assisted Machining

Various 2-D numerical simulations were carried out using the commercial software AdvantEdge Versions 5.2 and 5.3 to model ductile mode micro-Laser Assisted Machining (μ-LAM) of Silicon Carbide (4H-SiC). The cutting tool is a single point diamond. The workpiece material (SiC) is heated locally by a laser beam, which passes through the diamond tool tip. The workpiece is heated beyond the thermal softening point in order to study the effect of increased temperature. The cutting and thrust forces are reduced when machining is done above the thermal softening temperature. The simulations were carried out for two cases at different temperatures above and below the thermal softening point to study the effect of μ-LAM on the cutting and thrust forces. In the first case both the tool and workpiece material were heated to study the behavior at elevated temperatures. In the second case, a thermal boundary condition was provided on the top surface of the workpiece to simulate the laser heating effect keeping the tool at room temperature (20° C). In both cases the chip formation was observed and the changes in cutting and thrust forces were evaluated. The simulation results indicate a significant decrease in machining forces if Silicon Carbide is heated beyond the thermal softening temperature thus demonstrating the benefits of μ-LAM process.