Diffusionslöten von Aluminium mittels PVD applizierter Lotzusatzwerkstoffe

Diffusion brazing of aluminium by PVD applied filler metals Diffusion brazing of aluminium and aluminium alloys precoated with filler metal components enables fluxless wetting and obtains braze joints of high strength at moderate brazing temperatures. Previously deposited components of filler metals on the base materials as thin film, using Arc‐PVD‐process lead during a subsequently diffusion brazing process to the formation of a local liquid phase (transient liquid phase). The liquid phase is formed from the deposited thin film material and the base material and is solidified isotherm due to diffusion procedures. In doing so braze joints of higher melting point than brazing temperature can be realised. In this work, vacuum brazing of the two systems, Al‐Cu and Al‐Cu‐Si have been investigated. Cu and Al‐Cu‐Si were deposited on the base material using Arc‐PVD‐process. The base materials were pure aluminum and EN‐AW6060. Metallographic and scanning electron microscope analyses proved that the braze seam area after the completed diffusion brazing process shows similar structure and composition as the base material.