How do you check for welding defects?

The quality of FSW welds can be verified by non-destructive testing (NDT) and destructive testing to ensure compliance with the FSW ISO 25239 standard.
The visual inspection permits the observation of visible defects to the naked eye which appear as well on the butt and lap configurations. The flash appears as a burr on the edges of the joint. The wormhole is identifiable by an extended porosity on all or part of the length of the weld.
Other defects related to friction stir welding operations are internal. Only destructive tests can verify these welding defects. Control parts can be examined by different destructive testing techniques: microstructure, bending tests, tensile tests, macrographic examinations, chemical analyses…