No abstract

Transient liquid phase bonding (TLP) on AA 6082 samples were performed under ambient non‐vacuum conditions, which was possible by a suitable pre‐treatment. This treatment involves a zincate treatment followed by copper plating, which is a common industrial process and can be performed in large batches. This treatment allows to remove the natural aluminium oxide layer and to protect the aluminium surface from excessive oxidation. Different bonding conditions were investigated and showed the feasibility of the transient liquid phase bonding process for AA 6082. Energy dispersive X‐ray spectroscopy (EDX) investigations showed that the isothermal solidification is already terminated after 5 min. The microstructure of the bonding zone showed no metallurgical discontinuity such as eutectic microstructure or intermetallic Al–Cu phases. However the microstructure shows numerous voids with a size of approximately 30 µm in the bonding zone. It is assumed that these voids were formed during the bonding process due to solidification shrinkage and the presence of interfacial oxide layers. The transient liquid phase bonded samples that were mechanically tested under tensile load showed an average strength of approximately 270 MPa, the minimum yield strength required for the base material according to EN 754‐2 is 255 MPa. Due to the notch effect of the voids, the tensile sample failed under forced fracture and showed no plastic deformation.