Influence of Process Parameters on Weld Bead Width in Laser Beam Welding using Doe Technique

Abstract

The ability to create new advanced mathematical techniques with improved and unique properties has contributed to the progress of many areas of science. Especially in the past few decades, the applications in welding have relied heavily and in some critically on design of experiments. Accurately complied statistics help to achieve process efficiency in manufacturing activities, which in turn results in modernized production methods. The laser welding which is one of the modern manufacturing tools has the output variables which are characterized with parameters like depth of penetration and bead width in addition to the qualitative metallurgical factors. Laser input parameters like beam power, beam angle and welding speed are observed to have an influence on the output parameter weld bead width. A solid state Nd: YAG laser system with 2 kW capacity at WRI is used for conducting the experimental study. The effect of input process parameters on the weld bead width have been investigated using full factorial design of experiments, employing orthogonal array technique. The individual and interactive effect of input parameters on the depth of penetration is studied in detail for AISI 304 grade stainless steel. Using Analysis of Variance (ANNOVA), the significance of input parameters is evaluated. The effect of input parameters on the weld bead width is arrived at in the form of second degree polynomial equation using orthogonal contrast coefficients.