TWI

Friction stir processing (FSP) trial experiments were conducted on superplastic Zn, 21.1%Al eutectoid alloys using a modified milling machine and the results were evaluated in relation to residual microstructures, mechanical properties and damping capacities. FSP was performed at tool rotation speeds of 440-880 rpm, travel speeds of 100-800 mm/min and a tilt angle of 3 degrees. Microstructure was observed by optical microscopy. Tensile tests on specimens sampled from the stir zone were employed to study the distribution of tensile strength and elongation. Damping capacity was characterised by loss factor measurements. Issues discussed include fine equiaxial grain structure formation and strain rate sensitivity exponents in the stir zone.

7th International Symposium, 20-22 May 2008, 5B: Friction Stir Processing, Paper 02