Modelling heat flow around tool probe in friction stir welding

The objective of the present paper is to investigate the effect of including the tool probe in the numerical modelling of three-dimensional heat flow in friction stir welding (FSW). The heat flow close to the probe/matrix interface is investigated. In the models presented, the heat is forced to flow around the 'probe hole'. In this manner, the material flow through the probe region, which often characterises other thermal models of FSW, is avoided. This necessitates controlling the convective heat flow by prescribing the velocity field in the narrow shear layer at the tool/matrix interface. As a consequence the sliding, sticking, or partial sliding/ sticking condition can be modelled. Six cases are established, which are represented by three stages of refinement of the heat source model, combined with two different contact conditions, i.e. full sliding and full sticking.