Temperature Distribution within the Friction Stir Welding Tool

This work is motivated by several recent publications, which reported an unexpected temperature distribution within the welding tool during friction stir welding (FSW). It was found that the temperature in the tool shoulder was lower than that in the probe. This result appears to contradict the common assumption that the shoulder plays the dominant role in heat generation during friction stir welding. In an attempt to clarify this issue, we perform direct temperature measurements within the tool and numerical simulations of heat transfer. Extensive measurement data confirm that temperature within the shoulder is relatively low, which is in agreement with the literature data. Finite element modeling (FEM) shows that the lower temperature results from rapid cooling of the shoulder area due to enhanced heat transfer to the tool shank.