强激光冲击强化对7075铝合金的硬度影响  

The Influence of Intensive Laser Shock Peening on Microhardness of 7075 Aluminum Alloy

作　　者：王江涛[1] 陈菊芳[1] 

机构地区：[1]江苏理工学院材料工程学院,江苏常州213001

出　　处：《常熟理工学院学报》2016年第4期34-37,共4页Journal of Changshu Institute of Technology

基　　金：国家"863"计划子项目"典型产品运行安全寿命预测技术研究"(2012AA040104);国家自然科学基金项目"结构系统疲劳失效相关性的宏细观分析与可靠性建模"(51275221);"基于激光加热的施压成形机理和方法研究"(51105182);江苏省青蓝工程人才项目;常州市应用基础研究计划项目"基于高功率光纤激光熔覆成形的组织与性能研究"(CJ20159051)

摘　　要：采用GAIAR型Nd:YAG纳秒高功率激光器对7075铝合金进行激光冲击强化表面处理,借助高分辨透射电镜(TEM)对冲击后的表层进行微观组织观察,对冲击前后的试样进行了拉伸性能和微观硬度的对比测试.研究结果表明:激光冲击后7075铝合金表层微观硬度提高较大,尤其是4次冲击后硬度与未冲击相比提高29.6%,且较为均匀,硬化层的厚度接近1次冲击的4倍.激光冲击强化在铝合金表层诱导的高密度位错和晶粒细化是硬度提高的主要原因.7075 aluminum alloy was processed by laser shock induced by GAIAR Nd： YAG nanosecond highpower laser. Microstructures of them after laser shock peening （LSP） were observed by transmission electron microscopy （TEM）. Tensile properties and microhardness of 7075 aluminum alloy with LSP and without LSP werecarried out and compared. The results showed that the effect of LSP on microhardness of 7075 aluminum alloywas fairly useful and obvious. Especially with four times LSP, the microhardness was improved by 29.6% in contrast to the specimens without LSP, and the distribution of them was more uniform and the thickness of the hardened layer was about 4 times as much as it without LSP. High density dislocation and grain refinement in 7075aluminum alloy induced by laser shock processing are the main reasons for the increase of microhardness.

关 键 词：激光冲击 微观硬度 位错密度 晶粒细化 

分 类 号：TG174.1[金属学及工艺—金属表面处理]