微细波纹板激光热应力成形边界效应的抑制方法  

Edge-effect Suppression Method for Microcorrugated Sheets by Laser Thermal Stress Forming

作　　者：姚喆赫 范伟鑫 陈志敏 张群莉 姚建华[1,2,3] YAO Zhehe;FAN Weixin;CHEN Zhimin;ZHANG Qunli;YAO Jianhua(Institute of Laser Advanced Manufacturing,Zhejiang University of Technology,Hangzhou 310023,China;Key Laboratory of Special Purpose Equipment and Advanced Processing Technology,Ministry of Education and Zhejiang Province,Zhejiang University of Technology,Hangzhou 310023,China;College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023,China)

机构地区：[1]浙江工业大学激光先进制造研究院,杭州310023 [2]浙江工业大学特种装备制造与先进加工技术教育部/浙江省重点实验室,杭州310023 [3]浙江工业大学机械工程学院,杭州310023

出　　处：《中国表面工程》2024年第3期78-88,共11页China Surface Engineering

基　　金：国家自然科学基金(U1809220,52175443);浙江省“领雁”研发攻关计划(2022C01117)。

摘　　要：激光热应力成形为微细薄板结构的无模制造提供了解决方案,然而其边界效应严重影响成形精度。针对金属薄板激光热应力成形过程中的边界效应,采用振镜式激光,结合有限元模拟和成形试验分析激光工艺参数对边界效应的影响规律。研究了变速度、变方向以及两者耦合的边界效应抑制策略,进而用于微细波纹板成形过程。结果表明,扫描路径上的温度与应力分布不均是造成边界效应的主要原因,薄板成形过程中的热累积主要存在于扫描结束端,激光工艺参数是影响弯曲成形件变形的重要因素;采用变向-变速耦合策略比单方向扫描的相对角度变化减小77.8%,实现了深宽比大于0.75的微细波纹板精密成形。变向-变速耦合策略能够有效抑制微细波纹板激光热应力成形中的边界效应,为高质量微细薄板成形提供参考。Laser thermal stress forming,which is a contactless and highly flexible manufacturing technology,can minimize problems such as springback,cracking,and wrinkling caused by mold or tool manufacturing,thus providing a precision manufacturing solution for microcorrugated sheets.However,microcorrugated sheets are prone to edge effects due to the uneven distribution of energy input and constraint differences during the scanning process.Because of the multipass and multicycle scanning involved in the laser thermal stress forming process of microcorrugated sheets,the surface distortion and residual stress caused by the previous scanning affect the thermal deformation in the subsequent scanning.This effect is amplified by the superposition of edge effects during multiple scanning,which exacerbates the instability of microcorrugated sheet forming.Therefore,the suppression of edge effects in the laser thermal stress forming of microcorrugated sheets should be a major focus.In addition,the mechanism of the surface distortion caused by multipass coupling is complex.In this study,the effects of laser process parameters on the edge effect are analyzed by numerical simulations and experimental studies.A varying velocity round-trip coupling scanning strategy is proposed to suppress the edge effect and is also applied to microcorrugated sheet forming,as this provides a reference for the analysis and suppression of edge effects in multiple scanning.The heat accumulation and displacement distribution at the free end after scanning are analyzed through numerical simulations under various scanning strategies.An experimental platform of laser thermal stress forming is constructed.The specimen used in the experiments is 304 stainless steel sheets with dimensions of 30×30×0.4 mm.The study employs a 500-W oscillator continuous fiber laser with a laser power of 150–450 W,velocity range of 10–70 mm/s,and scanning number range of 5–20.Response surface analysis(RSA)is used to analyze the effects of different laser process parameters o

关 键 词：激光材料加工 波纹板 激光热应力成形 边界效应 抑制策略 激光工艺参数 

分 类 号：TN249[电子电信—物理电子学]