The study of material flow behaviour in dissimilar material FSW of AA6061 and Cu-B370 alloys plates

Friction stir welding is a solid-state joining process which proved to be very effective for similar low strength materials. However, the joining of dissimilar materials is far complex than the similar materials because of divergent material properties. The need to study friction stir welding of dissimilar materials is inevitable due to increasing demand of modern industries. In the current study, the joining of aluminium alloy (AA-6061) and copper alloy (Cu-B370) plates is accomplished for studying the material flow movement throughout welding zone. A novel material flow model for dissimilar material friction stir welding is proposed based on the temperature and strain rate dependent material properties. The model used the volume of fluid (VOF) approach in the commercial FVM package ANSYS fluent 14.5. Experiments are also conducted to validate the model with thermal profiles and optical micrographs. Furthermore, the effect of tool rotational and the welding speed are studied on the material movement. It is found that process parameter had a huge impact on the nugget zone formation during the welding. The tool rotaion and welding speed directly affect the amount of platisized material mixing.