Effects of yttrium and silicon contents in Hastelloy-X built by selective laser melting process

Santhosh Banoth*, Thaviti Naidu Palleda, Takuma Saito, Hideyuki Murakami, Koji Kakehi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

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.

Original languageEnglish
Article number163050
JournalJournal of Alloys and Compounds
Volume896
DOIs
Publication statusPublished - 2022 Mar 10

Keywords

  • Creep
  • Hastelloy-X
  • Hot cracking
  • Rare earth element yttrium
  • Selective laser melting
  • Silicon
  • Tensile, Oxygen-embrittlement

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Effects of yttrium and silicon contents in Hastelloy-X built by selective laser melting process'. Together they form a unique fingerprint.

Cite this