中国激光, 2010, 37 (10): 2662, 网络出版: 2010-09-25
激光单次冲击LY2铝合金微观强化机制研究
Micro-Structural Enhancement Mechanism of LY2 Aluminum Alloy by Means of a Single Laser Shock Processing
激光技术 激光冲击强化 塑性变形 晶粒细化 超高应变率 laser technique laser shock processing plastic deformation grain refinement ultra-high strain rate
摘要
采用激光冲击强化技术对LY2铝合金表面进行处理, 利用扫描电镜和透射电镜对塑性变形层深度方向的不同区域进行结构表征,测量了元素成分的变化,并对激光冲击强化铝合金的微观机理进行深入的研究。结果表明,激光冲击能够在LY2铝合金表面产生亚微米级的亚晶结构, 深度方向的位错结构从随机分布位错到位错线,再到位错缠结,最后到亚晶进行逐步演变,最终形成细化的晶粒。激光冲击的超高应变率对于粗晶的细化和最小平均晶粒尺寸的大小具有至关重要的作用。
Abstract
The effects of laser shock processing (LSP) on grain size, element content and microstructure are investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM) observations in the top surface, the sever plastic deformation layer, the minor plastic deformation layer and the substrate after a single laser shock processing. The influences of LSP on micro-structure and grain size of LY2 aluminum alloy are discussed, and the enhancement mechanism of a single LSP on LY2 aluminum alloy is also addressed. After a single LSP impact, the change of dislocation structure can be also clearly seen at different layers, i.e., it varies from dislocation lines (DLs) to dislocation tangles (DTs) and dense dislocation walls (DDWs), to subgrains or refined grains as functions of the distance from the top surface. It is found that the microstructure is obviously refined due to the ultra-high plastic strain induced by multiple LSP impacts.
鲁金忠, 罗开玉, 冯爱新, 钟俊伟, 孙桂芳, 张磊, 钱晓明. 激光单次冲击LY2铝合金微观强化机制研究[J]. 中国激光, 2010, 37(10): 2662. Lu Jinzhong, Luo Kaiyu, Feng Aixin, Zhong Junwei, Sun Guifang, Zhang Lei, Qian Xiaoming. Micro-Structural Enhancement Mechanism of LY2 Aluminum Alloy by Means of a Single Laser Shock Processing[J]. Chinese Journal of Lasers, 2010, 37(10): 2662.