Theses and Dissertations Collection

The mechanical properties of a commercially laser-welded 304 alloy were studied. A sample of thewelded material and a sample of the unwelded material were tensile tested to find that the welded sample allowed more ductility while maintaining the same ultimate tensile strength as the unwelded sample. Optical and scanning electron microscopy showed that the weld contained smaller average grain sizes than the surrounding metal. The weld was found by nanoindentation to have a higher hardness than the surrounding metal before the tensile test. Due to the tensile test, the weld experienced lower strain than the surrounding metal, as found by nanoindentation and x-ray diffraction. This information was used to approximate the mechanical properties of the weld and applied to a finite element analysis to corroborate the results with the tensile test data. The approximated strain response of the weld was also compared to a strain hardening model.