激光冲击中的“应变屏蔽”和“约束击穿”  

"Strain-screening" and "Constraint-breakdown" in Laser Shock Processing

作　　者：罗新民[1] 马辉[1] 张静文[1] 张永康[2] 

机构地区：[1]江苏大学材料科学与工程学院,镇江212013 [2]江苏大学机械工程学院,镇江212013

出　　处：《材料导报》2010年第5期11-15,共5页Materials Reports

基　　金：国家自然科学重点基金(50735001)

摘　　要：讨论了约束状态和激光冲击的高压、高能、超快及超高应变率对材料响应之间的2个共性问题。激光冲击时,当被冲击材料本身与表面自由约束层能完全约束受冲击区域表面的宏观形变而不影响强化效应时,称为应变屏蔽,此时被冲击件可视为厚件,材料内部将保留大量的应变微结构;反之,当被冲击材料不能约束冲击能量而产生宏观形变时,称为约束击穿,此时被冲击件可视为薄件,冲击效果以塑性变形为主。最后扼要介绍了这2种现象在材料表面强化和微成形制造领域中的应用。Two general common questions between the constraint conditions and the materials responses induced by the features of high pressure, high energy, ultra quick and super-high strain rate in laser shock process are discussed. When laser shocks, the material itself and the superficial confinement stratum can be able to completely restrain the macroscopic deformation on the shocked surface region, meanwhile remaining microscopically strain, which is called strain-screening,the shocked work can be regarded as thick-piece, and the material interior induces massive microstructures so as to be strengthened. Otherwise, when the shocked material can not be able to restrain the laser shock energy, but produce measurable deformation, which is called constraint breakdown, the shocked work can be regarded as thin-piece, and the material obtains visible plastic deformation. Finally, the practical application of ＂strain-screening＂ and ＂constraint-breakdown＂ in the material surface strengthening and in the micro-deformation manufacturing domain is succinctly introduced.

关 键 词：激光冲击 超高应变率 应变屏蔽 约束击穿 微结构 塑性变形 

分 类 号：TN249[电子电信—物理电子学]