Finite element analysis and experimental validation of microcrack formation in silicon carbide for laser-assisted grinding applications

Silicon carbide (SiC) is widely used in applications that demand high thermal and mechanical resistance. However, its hardness and brittleness pose significant challenges for machining. To mitigate these challenges, laser treatment can induce controlled cracks in the material, facilitating the machining process by making material removal more efficient. This study aims to analyze the nucleation of cracks in laser-treated SiC using finite element simulations (FEM) and the Mohr-Coulomb failure criterion. The simulations indicated that reducing the laser scan speed increases thermal stresses, generating radial and longitudinal cracks. These cracks nucleate in tensile regions ahead of the laser spot and propagate by shear within the spot. According to the failure criterion, cracks with depths of up to 0.200 mm were predicted. The experimental results corroborated these predictions, showing cracks with depths of up to 0.194 mm, along with increased crack density and width at lower scan speeds. The good agreement between simulated and experimental data validates the theoretical model, demonstrating its ability to accurately predict material behavior under laser processing conditions. This work provides a solid foundation for optimizing laser thermal treatments in hard materials like SiC, improving both crack control and machining efficiency.