The effect of weld parameters on friction stir welding of brass plates

More successful results have been obtained in butt- and overlap-joining of Al-alloy plates by a recently developed solid state joining technique, namely friction stir welding (FSW), than in more conventional fusion welding processes. In this joining technique, no fusion takes place in the joint area of the plates welded. This novel joining method also offers the potential to weld some other materials rather than Al-alloys, such as Mg-alloys, brasses and low strength steels. In this study, the applicability of friction stir welding to brasses, namely 90%Cu-10%Zn and 70%Cu-30%Zn alloys, has been investigated. The joint performance was determined by conducting optical microscopy, microhardness mesurements and mechanical testing (e.g. tensile and bend tests). The effect of welding speed on the joint quality at a given rotational speed of the stirring pin (i.e. 1600 rpm) was also determined for both alloys. The highest joint performances were obtained at a welding speed of 210 mm/min for both alloys.