Quantitative Analysis of Process Parameter Effects on Deposition Layer Geometry in DED Additive Manufacturing

Abstract

In laser-directed energy deposition (DED), the geometric characteristics of individual deposited layers—height (H) and width (W)—fundamentally determine the dimensional accuracy of final components. This study quantifies the effects of three key process parameters—laser power, scanning speed, and powder feed rate—on H and W to establish a quantitative basis for dimensional control. A full factorial design (5×4×3) was employed, generating 60 single-track samples. Three-way ANOVA was applied to identify significant factors, quantify contribution ratios, and examine interactions. Results show excellent model fit (H: R²=96.47%, W: R²=97.51%). For height H, powder feed rate dominates (57% contribution), followed by scanning speed (31%), while laser power shows no significant effect (P>0.05). For width W, laser power dominates (60%), followed by scanning speed (28%). A significant interaction exists between scanning speed and powder feed rate for width (P<0.001): at low speeds (<11.5 mm/s), increasing feed rate increases W; at high speeds (>11.5 mm/s), the opposite occurs. These findings reveal distinct parameter dominances—feed rate controls height, power controls width—providing a quantitative foundation for targeted parameter optimization in DED processes.