A Design of Experimental Approach to Determine the Effect of Process Parameters on Depth of Penetration in Laser Beam Welding

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 of depth of penetration. 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 depth of penetration 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 depth of penetration is arrived at in the form of second degree polynomial equation using orthogonal contrast coefficients.