Microindentation testing of environmental stress cracked welds in polyethylene

A discussion on microindentation testing of environmental stress cracked welds in polyethylene was presented. The process involved melting the two parts of matching faces to be welded, then forcing them together until they solidify. The weld quality was measured by its yield stress and ductility in a tensile stress, which depends on the microstructure, a function of its thermal history. The testing results showed that the microstructural differences between the weld and the bulk resulted in a lower yield stress in the weld and the microindentation curve revealed this as a lower overall load-displacement curve for the weld compared to the bulk.