Al-Si-Cu合金粉末扩散钎焊Al/Cu接头组织及性能

采用Al-Si-Cu合金粉末扩散钎焊铝铜异种金属,采用SEM,EDS和XRD分析接头微观组织结构,结合三元相图分析了接头形成机理,最后检测了接头力学性能.结果表明,在连接温度530℃,保温时间60 min,压力为1MPa时可形成均匀致密的接头,接头中存在大量条状和鱼骨状的Al-Si-Cu共晶组织,中间层与两母材结合界面处的组织结构不同,在靠近铜侧界面存在三种层状金属间化合物,其成分依次为Cu₃Al₂,CuAl和CuAl₂,在靠近铝侧界面存在一个扩散区,没有形成层状金属间化合物.接头的抗剪强度随保温时间的变化而变化,在保温60 min时达到35 MPa.

Microstructure and properties of diffusion brazed aluminum/copper joint with Al-Si-Cu alloy powder

Al-Si-Cu alloy powders were used as insert layers for diffusion brazing of aluminum/copper dissimilar metals. The microstructure of resulted Al/Cu joints was observed by SEM,EDS and XRD. The mechanism of joint formation was analyzed with ternary phase diagrams. The mechanical properties of the joints were tested. The results show that uniform and compact joints were obtained at 530℃ for 60 min under the applied pressure of 1 MPa. A large number of eutectic phases existed in the joint. The interfaces on both sides were different. Cu₃Al₂,CuAl and CuAl₂ formed near the interface on copper substrate side, but a diffusion area without IMC existed near the interface on aluminum substrate side. The shear strength of the joints changed with the holding time. The maximum shear strength of the joint brazed at 530℃ for 60 min reached 35 MPa.