Effects on Al2O3 Ceramics by Laser Shock Processing under Different Power Density

摘要

The ceramic of Al_2O_3 was processed by LSP (laser shock processing) under different power densities. The effects of different peak pressure that were carried out by different power densities had been analyzed, and the fracture microphology, which formed by the strong LSP, was studied with SEM (scanning electron microscopy). It was discovered that different features in the ceramic materials took place under different laser power densities. The brittle fracture comprised of intergranular fracture and cleavage fracture was the main mode at high power density (1.0 × 10~9W/cm~2), the radial fracture occurred in the ceramics when the peak pressure was higher than compressive strength. Although the peak pressure was lower than compressive strength when the laser power density was reduced to an appropriate level (0.6 × 10~9W/cm~2), subulate fracture developed from tensile-stress induced by reflected wave, and plastic deformation occurred. At the even lower power density(0.36 × 10~9W/cm~2), the feature of micro-plastic deformation can be observed.