University of Nebraska–Lincoln,
Keywords: laser shock peening, ceramics, surface strengthening
Summary:Laser shock peening (LSP) has been widely applied to metals to improve the fatigue and stress corrosion cracking resistance. However, the application of LSP to ceramic materials has been limited and the associated mechanisms are poorly understood. The research of our group in the last 7 years has developed a novel process of high-temperature LSP for ceramic materials, and investigated the microstructural changes and mechanical properties in ceramic materials (such as Al2O3 and SiC) by the LSP process. Transmission electron microscopy characterizations revealed significant dislocation activities near the surface and grain boundaries, suggesting that the localized plastic deformation can be generated in the brittle ceramic materials by LSP at room and elevated temperatures. X-ray diffraction analysis showed that the compressive residual stress in Al2O3 and SiC surfaces can extend from the surface to a depth of about 1 mm. The LSP-induced localized plasticity can improve the mechanical properties of ceramic materials, such as hardness, fracture toughness and bending strength. Related Publications: 1. F Wang, X Chen, D DeLellis, A Krause, Y Lu, B Cui. Microstructures and mechanical properties of α-SiC ceramics after high-temperature laser shock peening. Journal of the American Ceramic Society, 105 (4), 2411-2420 (2022). 2. F Wang, X Yan, L Liu, M Nastasi, Y Lu, B Cui. Surface strengthening of single-crystal alumina by high-temperature laser shock peening. Materials Research Letters, 9 (3), 155-161 (2021). 3. F Wang, X. Yan, C. Zhang, L. Deng, Y. Lu, M. Nastasi, B. Cui. Localized plasticity in silicon carbide ceramics induced by laser shock processing. Materialia, 6, 100265 (2019). 4. F. Wang, C. Zhang, X. Yan, L. Deng, Y. Lu, M. Nastasi, B. Cui. Microstructure-property relation in alumina ceramics during post-annealing process after laser shock processing. Journal of the American Ceramic Society, 101 (11), 4933-4941 (2018). 5. F. Wang, C. Zhang, Y. Lu, M. Nastasi, and B. Cui. Laser shock processing of polycrystalline alumina. Journal of the American Ceramic Society, 100 (3), 911-919 (2017).