TWI

A review is presented of the progressive emergence of conceptual tools associated with friction stir welding (FSW) at the Marshall Space Flight Center, USA, from the discovery of the shear surface, wiping metal transfer and the invention of a kinematic model to facilitate the treatment of metallurgical structure formation and process dynamics within a unified framework. Issues discussed include: the treatment of the shear surface as an adiabatic shear zone; rotating plug effects; lateral weld seam oscillation of bimetallic welds; ring vortex effects; tongue and groove structure of bimetallic self-reacting welds; interpretation of oscillation effects by a kinetic FSW model; thermal effects; drag and lateral tool forces; the inclusion of both strain-rate insensitive and strain-rate sensitive, temperature-dependent flow mechanisms; and a pressure-dependent tool/workpiece boundary condition.

9th International Symposium, 15-17 May 2012, Session 1: Plenary, Paper 02