TY - JOUR
T1 - Effects of yttrium and silicon contents in Hastelloy-X built by selective laser melting process
AU - Banoth, Santhosh
AU - Palleda, Thaviti Naidu
AU - Saito, Takuma
AU - Murakami, Hideyuki
AU - Kakehi, Koji
N1 - Funding Information:
This research was funded by the ALCA Program of the Japan Science and Technology Agency, JST (Grant no. JPMJAL1605 ) and by the AMADA Foundation ( AF-2018222-B3 ).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/3/10
Y1 - 2022/3/10
N2 - The effects of the addition of yttrium (Y) on the creep and tensile properties of Hastelloy-X built by a selective laser melting (SLM) process were studied. Two alloys were chosen: Hastelloy-X (Y-free) as a reference material and a specimen with 0.046 wt% yttrium (Y-added). Post-processing solution heat treatment (ST) was conducted at 1177 °C in air for 2 h, followed by air cooling to obtain appreciable mechanical properties. In the as-built condition, the Y-free specimen showed the formation of cracks; this was mainly due to the segregation of solute elements such as W, Si, and C at the grain boundaries and interdendritic regions. The Y-added specimen was free of cracks and showed longer creep life and rupture elongation than the Y-free specimen because the reduced Si content in the Y-added alloy eliminated cracking. In addition, the formation of Y2O3 oxides improved tensile elongation and creep properties by stabilizing solute oxygen contamination. After ST, both vertical and horizontal Y-added specimens presented better creep properties than ST Y-free specimens. This was mainly due to grain morphological change, carbides, and oxides formation at the grain boundary after ST heat treatment in the Y-added specimens.
AB - The effects of the addition of yttrium (Y) on the creep and tensile properties of Hastelloy-X built by a selective laser melting (SLM) process were studied. Two alloys were chosen: Hastelloy-X (Y-free) as a reference material and a specimen with 0.046 wt% yttrium (Y-added). Post-processing solution heat treatment (ST) was conducted at 1177 °C in air for 2 h, followed by air cooling to obtain appreciable mechanical properties. In the as-built condition, the Y-free specimen showed the formation of cracks; this was mainly due to the segregation of solute elements such as W, Si, and C at the grain boundaries and interdendritic regions. The Y-added specimen was free of cracks and showed longer creep life and rupture elongation than the Y-free specimen because the reduced Si content in the Y-added alloy eliminated cracking. In addition, the formation of Y2O3 oxides improved tensile elongation and creep properties by stabilizing solute oxygen contamination. After ST, both vertical and horizontal Y-added specimens presented better creep properties than ST Y-free specimens. This was mainly due to grain morphological change, carbides, and oxides formation at the grain boundary after ST heat treatment in the Y-added specimens.
KW - Creep
KW - Hastelloy-X
KW - Hot cracking
KW - Rare earth element yttrium
KW - Selective laser melting
KW - Silicon
KW - Tensile, Oxygen-embrittlement
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U2 - 10.1016/j.jallcom.2021.163050
DO - 10.1016/j.jallcom.2021.163050
M3 - Article
AN - SCOPUS:85120653438
SN - 0925-8388
VL - 896
JO - Journal of the Less-Common Metals
JF - Journal of the Less-Common Metals
M1 - 163050
ER -