Investigation of the tool effect on the strength of friction stir spot welded aluminum specimens: A comparative study

Abstract

Aluminum and its alloys are widely used in the automotive industry because of their light weight and good formability as well as malleability, and an alternative welding technique, the friction stir spot welding process, can be successfully used to join these materials. In this study, friction stir spot welding is applied to an AA 5754-H111 alloy to compare the effect of tool geometry and tool material on shear strength. Welds are made using different rotational speeds of tool and dwell times ranging from 500 to 1500 rpm and 6 s to 21 s, respectively. The experimental results showed that the combination of dwell time and rotational speed of tool as well as tool geometry and tool material have an important role in the strength of the joints. The total thickness and weld nugget diameter were also investigated in this study.