Friction taper plug welding of 10mm AA6082-T6

TWI Industrial Member Report Summary 768/2003

K Beamish

Background

The friction taper plug welding (FTPW) process was initially developed as an alternative repair technique for filling through thickness holes. In the allied process of taper stitch welding a series of interlinked taper plug welds is used to repair cracks. The FTPW process has been demonstrated in a variety of materials in thicknesses between 0.5 and 38mm. Friction processes such as FTPW do not always compete against established fusion processes in terms of cost and time but have been considered for critical repair applications where problems have been encountered with fusion processes, eg operation in hostile environments or when repairing materials not readily welded by fusion processes. However, improved reproducibility and weld quality must be achieved for the processes to be accepted in production applications.

Objectives

• To establish the current state of the art and applications of friction taper plug welding.
• To establish the effect of the major weld parameters on friction taper plug weld quality in an aluminium alloy.
• To determine the effect of machine characteristics on weld quality and process reproducibility.