中文摘要：

利用高功率、短脉冲Nd∶YAG激光对6061-T651铝合金进行表面冲击强化处理,并分别在200℃、300℃、400℃和500℃的温度下对其进行性能测试,从残余应力、显微硬度和微观组织等方面分析了激光冲击处理（LSP）对其在高温条件下性能的影响。研究结果表明中高温条件下激光冲击6061-T651铝合金的强化效果明显。200℃和400℃时试件的最大残余压应力出现在次表层,且温度越高残余压应力释放得越快,激光冲击硬化层深度约为0.3mm,500℃时的晶粒平均尺寸要比400℃时的大,晶粒尺寸和强化相是提高硬度的主要原因,不连续且粗大的晶界析出物提高了6061-T651铝合金的抗腐蚀性能。

英文摘要：

The 6061-T651 aluminum alloy samples are treated by laser shock processing（LSP） with high power and short pulse Nd∶YAG laser,and then are kept warm at 200 ℃,300 ℃,400 ℃ and 500 ℃ respectively.The effects of 6061-T651 aluminum alloy on mechanical properties after LSP are analyzed from residual stress,micro-hardness and microstructure during elevated temperature.The results indicate that the strengthening effect of 6061-T651 aluminum alloy by LSP at elevated temperature is obvious.The maximum residual stress of specimens are tested in subsurface at 200 ℃ and 400 ℃.At the same time,the higher the temperature,the faster the residual stress releases.The hardening layer depth of 6061-T651 aluminum alloy is about 0.3 mm.The primary cause of improving micro-hardness is grain size and strengthening phase,and the pitting resistance of 6061-T651 aluminum alloy is improved obviously by the big and discontinuous precipitated phase.