LIE Home • Issue Contents

Comparative Study of Quality Characteristics of Nd:YAG Laser Weldments in 316 Stainless Steel and Ti6Al4V
S. Chatterjee, S.S. Mahapatra, V. Bhardwaj, B.N. Upadhyaya and K.S. Bindra

Short pulse (ms) Nd:YAG lasers have been employed to weld thin sheets of 0.45 mm thickness so that damage to the weldment due to excessive concentrated heat generation can be avoided. The study specifically analyses the impact of laser welding parameters on quality measures of weld such as bead width (BW), heat affected zone (HAZ) and surface integrity/ surface roughness. A comparative study is made for laser butt welding of Ti6Al4V and 316 stainless steel of thin plates under identical machining conditions. The present study reports that surface roughness increases with increase in laser energy. It is also observed that micro-hardness value for 316 stainless steel in the fusion zone (FZ) is much higher than the base material (BM) in comparison to Ti6Al4V. This phenomenon may be attributed to higher cooling rate observed in case of 316 stainless steel as compared to Ti6Al4V. A desirability function approach (DFA) has been used to acquire optimal parametric settings for instantaneous optimization of the quality characteristics considered in this study for both the materials. The study indicates that the 316 stainless steel samples exhibit superior overall desirability value as compared to the Ti6Al4V elements. Comparative study on microstructural analysis for Ti6Al4V and 316 stainless steel weldments has been accomplished to determine the influence of parameters on microstructure.

Keywords: Nd:YAG laser, 316 stainless steel, Ti6Al4V, laser welding, weld geometry, heat affected zone (HAZ), surface roughness, microstructure, desirability function approach (DFA), response surface methodology (RSM)

Full Text (IP)