Deformation and Residual Stress Measurement of Alumina Ceramics after Dynamic Impacts

Alumina ceramics sintered at 1350°C ~ 1550 °C with various mechanical properties were tested using a minitype compressed air gun with mini WC material bullets impacting at a fixed bullet speed of 100 m/s. The resistance behaviour and deformation were recorded by visual examination. Cr3+ fluorescence was used to measure the induced residual stress and plastic deformation. The results show that the alumina with finest grains size and highest hardness is more effective in the bulletproof, the alumina sintered at 1450 °C experienced both the greatest extents of compressive residual stress (3.25 GPa) and plasticity (24 cm-1 shift).