Tomasz Wojdat

Soldering of aluminium with copper

Soldering of aluminium with copper becomes more significant, because of relatively low process temperature of about 400–450°C. It is applied not only in electrotechnical industry, in joining Al–Cu conductors, but also in cooling and air-conditioning equipment and in solar construction of collectors (Winiowski A. Lutowanie twarde aluminium i jegostopów – nowe trendy technologiczne, Biuletyn Instytutu Spawalnictwa, nr 6/2000, Fontargen GmbH. Löten in der Kälte- und Klimatechnik, Eisenberg. 2001 and Fontargen GmbH. Aluminium-Löten. Eisenberg 2003). In this paper, problems concerning Al–Cu soldering are presented. For soldering, zinc solders with the addition of 2, 4, and 15 wt% Al have been used. Results of wettability and spread factor measurements of zinc solders on aluminium and copper surface, as well as metallography, microhardness, and shearing tests of Al–Cu joints are presented. Effects of copper pipes with aluminium plate soldering with application of flux coating solders are also described.

The aggressive influence of lead-free solders and the protection of soldering devices against damage

The article presents the influence of lead-free solders on SnAg3.8Cu0.7 and SnCu0.7 tin matrices, as well as SnPb37 solder on the solubilization of copper under various conditions during dip soldering. The influence of lead-free solders, higher soldering temperatures and mobile soldering baths on the intensified effects of copper solubilization is demonstrated. Elements of soldering facilities coming into contact with SnCu3 solder-filled soldering bath are subject to solubilization and damage as a result. Protection of these elements and increase of their resistance by covering them with a ceramic layer based on Al2O3–TiO2 oxides was suggested.