The numerical analyses of the processes and characteristics of cladding layer formation in wire laser directed energy deposition under different substrate postures

Purpose The purpose of this study is to analyze the influence of substrate posture (SP) on the process and characteristics of cladding layer formation in wire laser directed energy deposition (WLDED). The study aims to improve the stability of WLDED process. Design/methodology/approach A dynamic simulation model for WLDED process is proposed and verified by comparing the cladding layer morphologies from the simulation and experiment. The processes and characteristics of cladding layer formation under horizontal and 50° inclined SPs are calculated and analyzed. Findings Under 50° inclined SP, the backward oscillation of liquid metal is facilitated and the liquid metal flow with larger momentum reaches higher part compared to that under horizontal SP since the backward component of gravity is opposite to the laser scanning direction. The flow velocity of liquid metal is greater. The maximum height and surface fluctuation amplitude of cladding layer under 50° inclined SP are significantly greater than that under horizontal SP. Additionally, the surface fluctuation distance of cladding layer under 50° inclined SP is increased compared to that under horizontal SP. Originality/value The proposed model can offer the theoretical guidance for understanding WLDED processes under inclined and horizontal SPs deeply. The results are benefit for improving the quality of manufactured parts of WLDED.