Cu/Al复合带固−液铸轧复合界面演化

摘要

Cu/Al clad strips are prepared using solid?liquid cast-rolling bonding (SLCRB) technique with ad160 mm × 150 mm twin-roll experimental caster. The extent of interfacial reactions, composition of the reaction products, and their micro-morphology evolution in the SLCRB process are investigated with scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and X-ray diffraction (XRD). In the casting pool, initial aluminized coating is first generated on the copper strip surface, with the diffusion layer mainly consisting ofα(Al)+CuAl2 and growing at high temperatures, with the maximum thickness of 10μm. After sequent rolling below the kiss point, the diffusion layer is broken by severe elongation, which leads to an additional crack bond process with a fresh interface of virgin base metal. The average thickness is reduced from 10 to 5 μm. The reaction products, CuAl2, CuAl, and Cu9Al4, are dispersed along the rolling direction. Peeling and bending test results indicate that the fracture occurs in the aluminum substrate, and the morphology is a dimple pattern. No crack or separation is found at the bonding interface after 90°–180° bending. The presented method provides an economical way to fabricate Cu/Al clad strip directly.%利用固?液铸轧复合(简称SLCRB)技术,在d160 mm×150 mm二辊实验铸轧机上制备Cu/Al复合带,并对其界面扩散层的反应程度、反应产物组成及显微组织演变规律进行SEM、EDS和XRD分析.结果表明,铸轧液相熔池内,液态铝液与铜带接触后在其表面形成初始渗铝层,界面成分主要为 α(Al)+CuAl2,且扩散层厚度在高温下逐渐生长变厚,最厚处约为10μm;进入低于kiss点的固相区后,扩散层在剧烈轧制延伸变形作用下破裂,界面两侧原始基材被挤出接触后形成新的复合界面,在铸轧出口处形成沿轧制方向弥散分布的CuAl2、CuAl和Cu9Al4,扩散层平均厚度由10μm减薄至5μm且较为均匀.剥离和折弯性能测试结果表明,所制备的Cu/Al复合带剥离断裂面出现在Al基体侧,断口呈显著韧性断裂,试件经90°~180°折弯后未出现界面撕裂现象.研究成果为高效短流程制备Cu/Al复合带提供了工艺基础.