Microstructure formation in micron-scale thin-walled Hastelloy X samples fabricated with laser powder bed fusion

Abstract Laser powder bed fusion (LPBF) has great potential for the fabricating complex geometries with improved functionality. In combination nickel alloys such as Hastelloy X, parts produced this technology find usage in high-temperature applications. Many studies have focused on microstructure of X fabricated via LPBF technology, but most been performed simple cubic geometries. Considering aforementioned applications, are often characterized by fine features, like very thin-walled structured, sub-1 mm range. However, little is known about fabrication structures. The study presented paper shows that wall thickness plays an important role formation. situ temperature measurements and thermal simulations showed a difference history. Local heat accumulation vicinity scanned tracks was observed sample consisting multiple tracks. Moreover, effect enhanced number tracks, leading to different melt pool morphologies. Significantly, coarser solidification cells were found near edges. addition, larger grains oriented parallel build direction samples 3 more while thinner samples, random orientation found.