Microstructures and mechanical properties of α-SiC ceramics after high-temperature laser shock peening

A novel high-temperature laser shock peening (HT-LSP) process was applied to polycrystalline α-SiC to improve the mechanical performance. HT-LSP prevents microcrack formation on the surface while induces plastic deformation in the form of dislocation slip on the basal planes, which may be caused by the combination of high shock pressure and a lower critical resolved shear stress at 1000℃. A maximum compressive residual stress of 650 MPa, measured with Raman spectroscopy, was introduced into the surface of α-SiC by HT-LSP, which can increase the nanohardness and in-plane fracture toughness of α-SiC by 8% and 36%, respectively. This work presents a fundamental base for the promising applications of HT-LSP to brittle ceramics to increase their plasticity and mechanical properties.