Characterization of stainless steel and galvanized iron 0.5 mm thick laser weld joints

The characterization of dissimilar metal welds is a promising area to understand the behavior of the weld joints. The previous study shows the characterization of similar and dissimilar metal welding of 1 mm and above thick sheets for changes in weld bead geometry, chemical composition and mechanical properties at different process parameters. The objective of this paper is to study the influence of Nd: YAG laser welding process parameters on 0.5 mm thick sheets to understand the overall behavioral characteristics of 304 L stainless steel and galvanized iron. The experiments are conducted as per Taguchi's orthogonal array design matrix. The samples are welded at different process parameters and examined for the variation in the microstructure, chemical composition, weld defects, grain size, phase contents, microstrain and dislocation density across the weld joint. The laser power and pulse duration are significantly affecting process parameters on weld bead geometry, porosity, mixing of metals and weld strength. The factors responsible for the reduction in weld strength are also identified. These findings are useful to understand the overall changes in weld characteristics and variation in mechanical properties. This study also helps to select process parameters for obtaining better quality weld joints in micro component welding.