(1.华中理工大学激光技术国家重点实验室,武汉 430074;
2. 广州建筑职工大学,广州 510655)
摘 要: 采用快-快正电子湮没仪分别测定了LY12CZ和纯铝经激光冲击处理后的正电子谱,激光冲击使LY12CZ和纯铝的平均寿命降低而捕获率提高,表明激光冲击使材料内部的缺陷浓度增加且缺陷浓度与激光功率密度呈指数关系。激光冲击硬化是由于激光冲击后在材料内部形成大量位错等缺陷,这些位错相互缠结在一起,相互钉扎,形成稳定的胞状组织,从而提高材料的力学性能。
关键字: 激光冲击(LSP) 正电子谱 缺陷浓度 冲击硬化
(National Key Lab of Laser Technology, Huazhong University of Technology, Wuhan 430074)
Abstract:Positron lifetime spectra of LY12CZ and pure Al with laser shock processing(LSP) by positron annihilation instrument were measured, that the average lifet ime decreased with increasing traping rates showed that the defect densities in the materials with LSP were improved. Besides, the relation between the laser power density and the defect densities was analysed, the effect of laser shock hardenin g was also investigated and explored.
Key words: laser shock processing positron lifetime spectra defect densities
laser shock hardening
Key words: laser shock processing positron lifetime spectra defect densities
laser shock hardening