TWI

The viscosity of aluminium alloy 6061-T6 was determined to obtain data necessary for the modelling of friction stir welding. A friction stir welding tool with a 5 mm diameter pin was plunged into an alloy disc (tool speeds 900-1500 rev/min, plunge depths 0-5.5 mm) and the thrust forces and torque values measured using a six-axis load cell. Temperatures were measured using a thermocouple at the tool tip and in the disc. Navier-Stokes and transient energy equations were used to calculate the velocities, temperature fields and viscosity values. Local heat source terms were determined by iteration using assumed viscosity values and shear rates until the appropriate viscosity values were established.

2nd International Symposium, 26-28 Jun 2000, Session 7, Paper 02