Microstructure evolution and mechanical properties of Hastelloy X alloy produced by Selective Laser Melting

Abstract

<jats:title>Abstract</jats:title><jats:p>Selective laser melting (SLM) is considered as an important additive manufacturing (AM) technology which can fabricate parts with complex geometry. However, it is difficult to predict the optimal SLM-parameters of metallic materials. In this study, orthogonal experiments were designed to study the influence of SLM-process parameters on the density and fabricated quality of Hastelloy X superalloy. Moreover, the relationship between microstructure evolution and performance of deposited microstructure was studied after heat treatment. The laser power, scanning speed and energy density have a significant effect on the density of the fabricated parts. The optimal parameters for determining Hastelloy X are 250 W laser power, 500 mm/s scanning speed, 100 μm hatch space, and 30 μmlayer thickness. The deposited microstructure is a lamellar microstructure in the horizontal direction and a columnar crystal in the longitudinal direction, and the microstructure is mainly martensite. After solid-solution and aging treatment, grain grows up. Martensite decomposes and the carbide M<jats:sub>6</jats:sub>C was precipitated during the aging process. The strength of the microstructure decreases slightly due to the growth of grain size.</jats:p>

On the current research progress of metallic materials fabricated by laser powder bed fusion process: a review

“…These deformations and Fig. 2 e Metal powders: (a) 316L stainless steel [81], (b) 24CrNiMo alloy [82], (c) Tie6Ale4V [83], (d) Ale12Si [84], (e) pure tungsten powder [85], (f) NiTi, (g) AlSi10Mg [86], (h) Inconel 718 superalloy [87], and (i) Hastelloy X alloy [88]. Fig.…”

Review—Importance of Atmospheric Gas Selection in Metal Additive Manufacturing: Effects on Spatter, Microstructure, and Mechanical Properties

“…61) Conversely, a high cooling rate suppresses precipitation of the strengthening phase, leading to a decrease in precipitation strengthening. 62,63) These changes in the properties of metallic materials as a result of the high cooling rate of L-PBF are expected to be improved and optimized by the careful selection of atmospheric gas species.…”

Ultrasonic-Assisted Electrochemical Milling of SLM-Printed Hastelloy X Based on Analysis of Material Passivation Characteristics

“…Due to the gradient effect of melt pool cooling, these SLM-printed (SLM-ed) structural parts often have defects such as cracks and porosity, 6 and exhibit different physical and chemical properties on the printed and stacked surfaces. 7,8 Temperature treatment was considered as one of the optimal methods to improve the printing defects of SLM-ed HX parts and to eliminate anisotropy. Many scholars have extensively studied the SLM-ed HX after heat treatment.…”