Surface Roughness of Additively Manufactured IN718 and H282 Superalloys from Multi-size and Multi-laser Machines

Laser Powder Bed Fusion (LPBF) of metallic components is unlocking new design options for high-efficiency gas turbine component designs not possible by conventional manufacturing technologies. Surface roughness is a key characteristic of LPBF components that impacts heat transfer correlations and crack initiation from co-located surface defects—both are critical for gas turbine component durability and performance. However, even for a single material, there is an increasing diversity in laser machines (single vs multi-laser), layer thicknesses (~20–80μ) and orientations to the build plate (upskin, vertical, and downskin) that result in significant variability in surface roughness. Build direction effects are particularly important when considering three-dimensional gas turbine components each having unique cooling features. This study systematically compares the external and internal surface roughness of two gas turbine superalloys—Inconel 718 and Haynes 282—from multi-laser and multi-size machines. This presented data will be discussed in detail, to show potential applicability of a 3D process signature surface across machines and substrate orientations for additively manufactured superalloys.