约束条件对薄板激光冲击表面完整性的影响  

Effect of constraint conditions on surface integrity of laser shocked thin plate

作　　者：杨恒基 杨文杰 张兴权 张国涛[1,2] 方进秀 裴善报 YANG Heng-ji;YANG Wen-jie;ZHANG Xing-quan;ZHANG Guo-tao;FANG Jin-xiu;PEI Shan-bao(Anhui Province Key Laboratory of Special Heavy Load Robot,Maanshan 243032,China;School of Mechanical Engineering,Anhui University of Technology,Maanshan 243032,China)

机构地区：[1]特种重载机器人安徽省重点实验室,安徽马鞍山243032 [2]安徽工业大学机械工程学院,安徽马鞍山243032

出　　处：《激光与红外》2022年第1期40-46,共7页Laser & Infrared

基　　金：国家自然科学基金项目(No.51675002);安徽省重点研究与开发计划项目(No.201904a05020065);安徽省高校自然科学研究项目(No.KJ2019A0084);省级大学生创新创业训练计划项目(No.S202010360253)资助。

摘　　要：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,远小于两端夹持试样。两种约束条件下试样深度方向显微硬度的区别并不明显,试样表面附近均产生了细小的孪晶,高密度的形变孪晶使材料的显微硬度得到提升。当板材厚度小于2 mm时,底部全约束条件下的残余应力场效果明显较好。两种约束条件下应力波的反射情况明显不同,反射的应力波影响了薄板表面的残余应力场。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.

关 键 词：激光冲击强化 约束条件 表面完整性 304不锈钢 薄板 

分 类 号：TN249[电子电信—物理电子学]