A transient finite element analysis of thermoelastic effects during inertia friction welding

A fully coupled torsional elastic–plastic finite element model has been used to assess the thermoelastic effects (thermal expansion) during the inertia friction welding process of the nickel–chromium alloy, Inconel 718. The two workpieces are initially in conforming contact and the generation of heat causes local thermal expansion which results in a non-uniform pressure distribution across the contact area and a reduction in the contact area between the workpieces. Eventually the material around the weld interface heats up sufficiently for the axial load to cause plastic flow to occur which results in an increase in the contact area. The effect of the axial pressure and sliding velocity on the minimum contact area and the time taken to recover 90% of the initial contact area is investigated using the finite element model.