Optimization of Process Parameters to Minimize Porosity and Splash in Cold Metal Transfer and Pulse Wire Arc Additive Manufacturing of High-Strength Aluminum Alloy

Abstract

This article examines the application of advanced cold metal transfer plus pulse composite arc technology for the thin-walled additive manufacturing of high-strength aluminum alloy AA2024. Response surface methodology is employed to design experiments and variance analysis is utilized to assess the model's reliability. Results are further optimized and validated using the non-dominated sorting genetic algorithm II. The focus is on optimizing key process parameters—wire feeding speed, interlayer temperature, protective gas flow rate, and welding wire elongation—to minimize porosity and splash. A comprehensive analysis of parameter interactions is conducted using contour maps and response surface plots. The findings indicate that wire elongation most significantly affects porosity, while wire feeding speed has the greatest impact on splash. The optimized parameters effectively reduce grain size under low heat input conditions, decrease hydrogen-induced porosity and solidification defects, achieving a porosity rate of 0.46% and a splash rate of 0.83%.