铜/铝复层板成形极限视觉测量方法及成形性能

Forming Limit Vision Measurement and Formability of Cu/Al Clad Metals

基于数字图像相关法(DIC)与双目视觉技术,提出并实现了一种用于爆炸焊接制备的铜/铝复层板成形极限应变的视觉测量方法,利用有限元模拟结果对该方法进行验证。根据DIC方法获得的板料成形极限应变,分析热处理工艺及接触状态对铜/铝复层板成形极限的影响,使用扫描电子显微镜对界面与断口形貌进行观察分析。结果表明:DIC方法测得的铜/铝复层板失稳破裂时的最大主应变与有限元模拟结果的相对误差为0.1%,且应变值分布与有限元模拟吻合也较好;铝在内层时复层板成形极限大于铜在内层时的成形极限;经过退火处理的铜/铝复层板成形性能优于未退火时的性能;铜/铝复层板发生失稳断裂时,界面产生脱离。

To measure the forming limit strain of Cu/Al clad metal made by explosive welding technique,a new optical measurement method based on the digital image correlation （DIC）method and binocular stereovision was proposed and implemented.The FEM results were used to verify the strain measurement accuracy of the DIC method.Based on the limit strain of Cu/Al clad metals by DIC method,the influences of heat treatment and contact status on forming limit were analyzed.Al-so,the interfacial and fracture structures were analyzed with SEM.The results demonstrate that the relative error of major strain between DIC method and FEM mothod is 0.1% when Cu/Al clad metals are broken,and the strain distributions agree finite element simulation results well.The forming limit of the clad with Al in the inner layer is higher than the clad with Cu in the inner layer.The formabili-ty of the annealed clad is superior to the not annealed one.The clad is broken at both sides with inter-face fracture.