Toward defect-free components in laser metal deposition with coaxial wire feeding through closed-loop control of the melt pool temperature

Laser metal deposition (LMD) is an additive manufacturing process in which a powder or wire added to laser-induced molten pool. This localized of material used for the manufacturing, modification, and repair wide range components. The use as feedstock offers various advantages over terms contamination environment, utilization rate, ease handling, price. However, achieve stable well defined geometrical microstructural properties many layers, precise knowledge on effects input variables resulting characteristics required. In this work, melt pool temperature was parameter LMD with coaxial feeding stainless steel, made possible through dedicated closed-loop control system based pyrometry. Initially, determined different conditions obtained. Within range, cause-effect relationships between geometry were investigated individual weld beads. It found that positively correlated width bead dilution. addition, dependence microhardness distribution cross section demonstrated, increased negatively affecting hardness.