The investigation on the influence of key process parameters on the fabrication properties of CMT thin-walled structure

Abstract

Wire arc additive manufacturing (WAAM) has demonstrated significant potential in fabricating metal structural components due to its high efficiency and low cost. However, applying this technology to thin-walled structures remains challenging owing to two key issues: pronounced heat accumulation and poor dimensional accuracy control. To investigate the influence of process parameters on the forming quality of thin-walled structures, this study focused on four critical parameters in the cold metal transfer (CMT) process, including Travel Angle (α), Work Angle (β), Wire Feed Speed (WFS), and Travel Speed (TS). An L25 (5⁴) orthogonal experiment was conducted to investigate the effects and correlations of these process parameters on the relative density and surface morphology of the fabricated structures. The results showed that relative density was most substantially affected by WFS. As WFS increases, the relative density of printed parts gradually decreases. At a WFS of 3 m/min, the optimal average relative density of the formed parts reached 98.69%. Under this condition, the best-performing parameter combination for achieving the highest relative density was A1B1C1D2. Meanwhile, TS exhibited the greatest influence on surface morphology, followed by Work Angle. When TS was 14 mm/s and Work Angle was 0°, both interlayer roughness and intralayer roughness reached their minimum values. The optimal process parameter combination for achieving the best surface morphology was A2B1C4D2. Analysis shows that parameter combinations should be selected based on component functional requirements, as mechanisms underlying optimal relative density and surface morphology differ.