Edge and corner effects in selective laser melting of IN 625 alloy

Abstract

Experimental investigations on top surface of prismatic specimens, manufactured by Selective Laser Melting of IN 625 alloy, were carried out in order to assess the influence of laser power and scanning speed on edge and corner effects. Since the melt-pool behaviour is strongly influenced by the process parameters, all specimens were manufactured with no contour using the same layer thickness, hatch distance and scanning strategy at different levels of laser powers and scanning speeds. 3D laser surface scanning was performed in order to measure surface changes. The experimental results have revealed that melt-pool behaviour during solidification generates elevated ridges on both specimen sides and corners that are strongly influenced by the energy input. The edge ridges width increases with increasing the laser power and decrease with increasing the scanning speed, the rising of corners being much more pronounced. On the contrary, at constant laser power and variable scanning speeds the edge and corner ridges decrease.

Laser Powder Bed Fusion Process Parameters’ Optimization for Fabrication of Dense IN 625

“…The study also provides useful information for selecting the appropriate workspace of process parameters to obtain high densification or low surface roughness or a suitable combination of the two. This basic set of process parameters was used in other studies made by the authors to assess the edge and corner effects during selective laser melting [57], the tensile strength anisotropy of the additive manufactured IN 625 using a Lasertec 30 SLM machine [56], and regarding complex-shaped parts manufacturing [58,59]. Future research will be conducted regarding the appropriate process parameter definition for Lasertec 30 SLM manufactured Ti-based alloys.…”

Microstructural aspects of the protective ceramic coatings applied on the surfaces of refractory alloys produced by additive manufacturing

“…The utilization of SLM to manufacture components for high demanding industries is still limited and driven by the existing metal powder grades, efficiency and process cost. The SLM produced materials have a high level of anisotropy of structural and mechanical properties depending on the process parameters and build orientation [1,2]. The limited surface quality of parts obtained by SLM is one of the major drawbacks restricting its application.…”