Influence of Powder Type and Layer-Dependent Energy Input on Multi-Layer Laser Cladding of Ductile Cast Iron

This study investigates the effects of powder type and layer-dependent energy input on the structural and mechanical performance of multi-layer laser cladding applied on FGS600-3A ductile cast iron. Three cladding powders (Ferro 55, Castolin 16604, and Metco 41C) were deposited under constant and variable energy input to examine the effects on macrostructure, porosity, microhardness, residual stresses, and thermal history. The results demonstrate that powder composition plays a decisive role in deposition quality. Ferro 55 exhibited the lowest porosity and the most favorable hardness distribution, whereas Metco 41C had high porosity, low hardness, and severe transverse cracking. Castolin 16604 displayed intermediate performance with deeper high-hardness penetration. Layer-dependent energy strategies improved porosity and hardness behavior for Ferro 55 and Castolin 16604; however, excessively low energy input limited hardness depth. Residual stress measurements revealed low stress levels for Ferro 55, compressive stress for Castolin 16604, and high tensile stress for Metco 41C, correlating strongly with cracking tendency. Overall, Ferro 55 and Castolin 16604 were identified as suitable candidates for multi-layer repair and surface modification of cast iron molds, while Metco 41C demonstrated limited applicability due to its porosity, hardness, and stress characteristics. This study emphasizes the importance of layer-specific parameter optimization to achieve defect-free and mechanically strong laser cladding.