TWI

Friction stir welding trials, comprising double-sided butt welding of plates of thickness 10-11 mm, were conducted to investigate the weldability of copper and its alloys and to determine the correct process parameters (welding and rotation speeds) and tool materials. The materials studied were electrolytically refined oxygen-free copper, phosphorus-deoxidised copper with high residual phosphorus, aluminium bronze (Cu, 5%Al, 5%Zn, 1%Sn) and cupronickel (Cu, 25%Ni). Flow stresses of parent materials were determined using hot tensile tests at 20-900 deg.C. The welded joints were characterised by transverse tensile tests, hardness measurements, three-point bend tests, radiographic inspection, SEM, electron backscatter diffraction and hydrogen sickness tests. The performances of eight tool materials were compared.

5th International Symposium, 14-16 Sep 2004, Session 5B: Copper Alloys/Magnesium Alloys, Paper 02