%0 journal article
%@ 0921-5093
%A Springer, H., Kostka, A., dos Santos, J.F., Raabe, D.

%D 2011
%J Materials Science and Engineering  A
%N 13-14
%P 4630-4642 
%R doi:10.1016/j.msea.2011.02.057
%T Influence of intermetallic phases and Kirkendall-porosity on the mechanical properties of joints between steel and aluminium alloys
%U https://doi.org/10.1016/j.msea.2011.02.057
13-14 
%X The formation of intermetallic reaction layers and their influence on mechanical properties was investigated in friction stir welded joints between a low C steel and both pure Al (99.5 wt.%) and Al–5 wt.% Si. Characterisation of the steel/Al interface, tensile tests and fractography analysis were performed on samples in the as-welded state and after annealing in the range of 200–600 °C for 9–64 min. Annealing was performed to obtain reaction layers of distinct thickness and composition. For both Al alloys, the reaction layers grew with parabolic kinetics with the η phase (Al5Fe2) as the dominant component after annealing at 450 °C and above. In joints with pure Al, the tensile strength is governed by the formation of Kirkendall-porosity at the reaction layer/Al interface. The tensile strength of joints with Al–5 wt.% Si is controlled by the thickness of the η phase (Al5Fe2) layer. The pre-deformation of the base materials, induced by the friction stir welding procedure, was found to have a pronounced effect on the composition and growth kinetics of the reaction layers.