The scale of ‘Stir’ were taken from a test sample made to test the parameters whilst stirring layers of brass and copper. The section of the metal was chosen carefully to select the most unusual patterning. Although copper and brass are relatively compatible metals, using friction stir welding technology to stir them together for decorative proposes, is relatively unexplored.
Friction Stir Welding is a technology that was invented and patented by TWI in Sheffield.
In friction stir welding, a tool with a probe is rotated whilst being forced into the metal, usually the area where two plates are held together. The frictional heat that is generated by this process softens the metal sufficiently to produce a ‘plastic’ flow that effectively stirs the metal from each section into the other to create a weld. Unlike normal welding, the metals never melt and friction stir welding is considered a ‘solid phase welding method’.