Properties of steel-aluminum joints generated by combining continuous and pulsed laser radiation

The combination of a continuous and a pulsed laser beam in a common process zone makes it possible to join aluminum and galvanized steel. This method does not require the use of chemical fluxes. It can be applied to different joint geometries such as double-flanged joints and lap joints. The basic microstructure of these joints is discussed using metallographic cross-sections. The properties of the intermetallic iron-aluminum compounds are examined in greater detail using methods such as energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). The results from these measurements indicate that the use of wire material alloys containing silicon leads to the formation of ternary phases. The joints exhibit a high strength in mechanical tests even when cyclic loads are applied.