激光冲击喷丸与激光辐照LY12铝合金材料拉伸力学行为的实验研究

Experimental Study of Tensile Behavior of LY12 Aluminium Alloy Processed by Laser Shot Peening and Laser Irradiation

为了研究激光冲击喷丸与激光辐照处理后LY12铝合金材料的微尺度变形特点和失效机理,对经过不同激光功率密度处理后的LY12铝合金材料,在扫描电镜下进行了原位拉伸力学行为和失效机理研究。在扫描电子显微镜(SEM)下,得到各组试件的拉伸载荷曲线和不同载荷下的微观区域图像,并利用数字图像相关技术进行不同载荷下的微观区域全场变形分析,并对拉伸断口形貌也进行了分析。研究表明:激光处理的功率大小对LY12铝合金拉伸最大载荷有明显的影响,激光处理的交界处有较强的应变集中。

In order to have an insight into the microscale deformation characteristics and failure mechanism Of LY12 aluminium alloy processed by laser shot peening （LSP） and laser irradiation （LI）, in-situ tensile behavior of the alloy sample was studied by loading machine and observed under scanning electron microscope （SEM）using different power densities laser shot peening and laser irradiation. Tensile load curves of all specimens and micro-regional images of SEM were obtained. Using digital image correlation （DIC） technique, micro-regional deformation under different loads was measured through SEM images. The fracture surface of these failure tensile specimens were taken by SEM and analyzed by DIC. Experimental results show that the largest LY12 aluminium alloy tensile load is significantly affected by laser power density and the junction area processed by laser treatment has quite strong strain concentration.