Control of Crystallographic Texture and Mechanical Properties of Hastelloy-X via Laser Powder Bed Fusion

Shinya Hibino,Tsubasa Todo,Ozkan Gokcekaya,Takayoshi Nakano,Yuichiro Koizumi,Takuya Ishimoto,Kenichiroh Igashira

doi:10.3390/cryst11091064

Shinya Hibino, Tsubasa Todo + Show 5 more

Open Access

https://doi.org/10.3390/cryst11091064

Copy DOI

Journal: Crystals	Publication Date: Sep 3, 2021
Citations: 26	License type: CC BY 4.0

Affiliation: Osaka University, Kawasaki Heavy Industries (Japan)

Abstract

The influence of various laser powder bed fusion (LPBF) process parameters on the crystallographic textures and mechanical properties of a typical Ni-based solid-solution strengthened alloy, Hastelloy-X, was examined. Samples were classified into four groups based on the type of crystallographic texture: single crystalline-like microstructure with <100>//build direction (BD) (<100>-SCM), single crystalline-like microstructure with <110>//BD (<110>-SCM), crystallographic lamellar microstructure (CLM), or polycrystalline microstructure (PCM). These four crystallographic textures were realized in Hastelloy-X for the first time here to the best of our knowledge. The mechanical properties of the samples varied depending on their texture. The tensile properties were affected not only by the Schmid factor but also by the grain size and the presence of lamellar boundaries (grain boundaries). The lamellar boundaries at the interface between the <110>//BD oriented main layers and the <100>//BD-oriented sub-layers of CLM contributed to the resistance to slip transmission and the increased proof stress. It was possible to control a wide range of crystallographic microstructures via the LPBF process parameters, which determines the melt pool morphology and solidification behavior.

Highlights

Metal additive manufacturing (AM) is a highly promising manufacturing method that enables the production of arbitrary three-dimensional shapes [1,2,3,4]
We examined the influence of a wide range of process parameters on the crystallographic textures and mechanical properties of a typical solid-solution strengthened alloy, Hastelloy-X
Among the four groups of crystallographic textures obtained in this study, SCM, crystallographic lamellar microstructure (CLM), and -SCM, which were presumed to have been obtained by characteristic solidification phenomena in the Laser powder bed fusion (LPBF) process, are discussed with a focus on the melt pool, which is a basic unit of solidification

Summary

Introduction

Metal additive manufacturing (AM) is a highly promising manufacturing method that enables the production of arbitrary three-dimensional shapes [1,2,3,4] Many studies employing this technique have used a variety of metallic materials, including stainless steels [5,6,7,8,9], Al alloys [5,10], Ti alloys [5,11,12,13], Ni-based superalloys [14,15], high-entropy alloys [16,17], metallic glasses [18], and intermetallic compounds [19,20]. Solid-solution strengthened alloys are widely used in combustor components that require good formability for complex shapes and oxidation resistance [30]. γ” precipitation strengthened alloys are utilized for many components, such as shafts and disks, which are not directly exposed to combustion gases and require excellent mechanical properties in the medium-temperature range, up to 700 ◦C [31]. γ precipitation strengthened alloys are generally utilized for turbine components that require excellent creep properties [32]

Methods

Discussion

Conclusion