Empirical modeling and optimization of kerf characteristics in Nd-YAG laser cutting of Al 6061-T6 sheet

Al alloys are the second most useful metal worldwide after the steel due to its high strength-to-weight ratio and corrosion resistance properties. In the present scenario, for creating contours in the sheet metals with close tolerances and high precision, laser beam cutting is preferred. During laser beam cutting of Al alloys, the reflectivity of the alloy possesses some difficulties to absorb the laser light. Such problems can be avoided using the shorter wavelength laser. This paper presents the modeling and optimization of kerf characteristics in Nd-YAG laser cutting of Al 6061-T6 sheet. In this study, kerf width (top and bottom side) and top kerf deviation are considered as kerf characteristics which are the functions of lamp current, pulse width, pulse frequency, and cutting speed. Box–Behnken design has been used for conducting the experiments and the experimental results have been further used for developing the response surface models and optimizing the responses using response surface methodology and grey relational analysis, respectively. Application of grey relational analysis has reduced the bottom kerf width by 12.5% and 7.75% along with straight and curved cut profiles respectively.