Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Microelectrochemical investigation on aluminium-steel friction welds

: Schneider, M.-E.; Langklotz, U.; Michaelis, A.; Arnold, B.


Surface and Interface Analysis 42 (2010), No.4, pp.281-286
ISSN: 0142-2421
Journal Article
Fraunhofer IKTS ()
aluminium alloy; corrosion; crystal microstructure; friction welding; magnesium alloy; scanning electron microscopy; silicon alloy; steel; surface structure; weld; X-ray chemical analysis

Aluminium-steel friction welds (AlMgSi0.5/C35 and AlMgSi0.5/X5CrNi18-10) were electrochemically investigated in a NaAc/HAc buffer (pH 5.9) and 0.1 mol/l NaCl using the microcapillary technique. This technique allows a lateral resolution of electrochemical measurements. However, microscopic investigations and scanning electron microscopy/energy dispersive X-ray SEM/EDX measurements show that the reaction zone (RZ) and the heat affected zone (HAZ) of the welds are smaller than the microcapillary diameter. This paper discusses the advantages and limitations of the microcapillary technique in view of friction welds. Nevertheless, the electrochemical experiments allow a clear detection of the changing active surface area and the correlation to the microstructure (intermetallics). The application of microcapillary measurements on samples which were exposed in marine climate for 2 years shows a good correlation between the local potential measurements and the local corrosion phenomena.