Modeling and Optimization of Laser Direct Joining Process Parameters of Titanium Alloy and Carbon Fiber Reinforced Nylon Based on Response Surface Methodology

Abstract

A laser direct joining (LDJ) experiment of titanium alloy (Ti-6Al-4V) and carbon fiber reinforced nylon (PA66CF20) is presented here using diode laser equipment. Experimental design and experiment of LDJ are carried out according to a single process parameters range obtained from the previous experiment. Response surface methodology (RSM) in Design-Expert v7 software is adopted to establish the mathematical model between LDJ process parameters and joint quality. Then the interaction effects of joining process parameters (laser power, scan speed and stand-off distance) on joint quality are investigated using analysis-of-variance (ANOVA), and the result shows that the interaction effect of laser power and scan speed on joint quality is the greatest. Finally, the predicted values from the mathematical model established by RSM are compared with the experimental values, and the process parameters are optimized to obtain the strongest joint strength. The result suggests that the predicted values are in good agreement with the experimental ones. The purpose of predicting and optimizing joint quality based on reasonable process parameters is achieved.