Relationship modelling for surface finish for laser-based additive manufacturing

Nickel-based superalloys belong to a special class of high-performance alloys that feature large amounts of nickel. The uniqueness of superalloys lies in their design features, most notably mechanical strength, durability, etc. Inconel 718 (IN718) is a nickel-based superalloy that exhibits high tensile and impact-resistant properties, along with good high-temperature corrosion resistance. Selective Laser Melting (SLM) is additive manufacturing (AM) technology aimed at melting and fusing metal powders using high power density lasers to produce precision functional parts. The accuracy and functional characteristics of manufactured parts are highly dependent on process parameters. The processing parameters that control the SLM process comprise laser power (P), hatch spacing (HS), exposure time (t), and border power (BP). This work primarily focuses on finding the combined effect of these process parameters on the surface roughness (SR) and ultimate tensile strength (UTS) of IN718 manufactured by SLM using the design of experiments (DOE).