退火温度对铜/铝异步冷轧复合带组织与拉伸性能的影响

Effect of annealing temperature on microstructure and tensile properties of Cu/Al composite belt produced by asymmetrical cold rolling process

采用异步冷轧复合工艺制备铜/铝复合带,研究轧后退火温度和拉伸应变速率对复合界面组织和力学性能的影响.利用扫描电镜观察界面显微组织和拉伸断口形貌,并通过线扫描分析界面元素分布,进行不同应变速率的拉伸实验研究复合带的力学性能.结果表明,较高的退火温度可促进界面扩散层的生长,在350℃时形成三层结构;退火温度的提高使复合带抗拉强度减小而延伸率增大,应变速率的提高使抗拉强度和延伸率均增大,但在退火温度超过350℃后增幅减小;退火温度和应变速率越大,复合带拉伸断口的开裂程度越大,复合界面的过渡作用越弱.

The asymmetrical cold-rolling bonding process was used to fabricate Cu/Al composite.Interfacial microstructure and mechanical properties were investigated.The interfacial microstructure and tensile fracture morphology were observed by scanning electron microscopy.The tensile tests with different straining rates were carried out to study the mechanical properties.The distribution of interfacial elements was analyzed by the line scanning.The results indicated that higher annealing temperature can promote growth of the interfacial diffusion layer,which forms a three-layer structure at350℃.Enhancing the annealing temperature can decrease the tensile strength and increase the elongation ratio.Increasing the strain rate can increase both the tensile strength and elongation ratio when the annealing temperature exceeds350℃.A higher annealing temperature and strain rate can increase the crack angle of tensile fracture and weaken the interfacial transition.