约束条件对薄板激光冲击表面完整性的影响

为了研究约束条件对薄板激光冲击表面完整性的影响,对厚度为1 mm的304不锈钢薄板进行了激光冲击强化处理,分析了两端夹持和底部全约束条件下,板材表面形貌、显微硬度和微观组织的差异,并通过数值模拟和实验研究了不同厚度板材的表面残余应力分布和约束条件的影响机理.结果表明,底部全约束试样表面凹坑深度约14μm,远小于两端夹持...

Effect of constraint conditions on surfaceintegrity of laser shocked thin plate

In order to study the effect of constraint conditions on the surface integrity of laser shocked thin plate,304 stainless steel sheets with thickness of 1 mm was treated by laser shock processing.The differences in surface morphology,microhardness and microstructure of the sheet under the conditions of both ends clamped(BEC)and bottom fully constrained(BFC)were analyzed.The surface residual stress distribution of different thickness plates and the influence mechanism of constraint conditions were studied by numerical simulation and experiment.The results show that the crater depth on the surface of BFC sample is about 14μm,which is far less than that of BEC sample.The difference of the microhardness in the depth direction of the specimen under the two constraint conditions is not obvious.Fine twins are generated near the surface of the two samples,and the high density of deformation twins improves the microhardness of the material.When the thickness of the plate is less than 2 mm,the residual stress field under the bottom full constraint condition is significantly better.The reflection of the stress wave is obviously different under the two constraints,and the reflected stress wave affects the residual stress field of the thin plate surface.