The technique also provided further
fundamental understanding of aluminium resistance spot welding (RSW) process; especially with
respect to the presence of an outer fused ring. The fundamental aspect of this study was underpinned
using the NDT technique for a real assembly; challenging the technique with access issues, different
material combinations, multiple joint stacks and independent measurements. The non-destructive test
analyses obtained correlated well with actual tear down results and offered further encouragement that
the C-scan technique is viable as a production tool if a suitably flattened surface can be provided.