Download file (14.7MB)
Download as zip (13.2MB)

コレクション

引用

説明:

This work investigates the effects of substrate preheating and processing parameters on the crystallographic texture of Hastelloy X (HX) deposited on a single crystal (SX)-like Ni substrate using laser powder bed fusion (L-PBF) process. Single- and multi-track experiments together with HX deposited on SX-like Ni substrate, were examined under varying laser powers and scanning speeds, with substrate preheating applied using a flat-top beam. A heat transfer model was employed to simulate the thermal history of melt pool. The results showed that higher laser power and lower scanning speed, combined with substrate preheating, produced larger melt pools and promoted elongated columnar grains formation throughout the Z-direction. Increasing the linear energy density (LED) from 1.5 J/mm to 5 J/mm at substrate preheating of 200 °C reduced the temperature gradient (G) by approximately -16%, as well as the solidification rate (R) and cooling rate (G×R) by -87% and -89%, respectively. These reductions in solidification kinetics promoted coarser primary dendrite arm spacing (PDAS), increasing from ~1.2 µm to ~2 µm. Moreover, substrate preheating improved metallurgical bonding and promoted epitaxial columnar growth, resulting in a strong <001> texture extending from the SX-like Ni into the HX layers. Consequently, the multiple of uniform distribution (MUD) increased from 2.5 to 4 under higher energy density (E) with substrate preheating. The findings demonstrate that high E and substrate preheating effectively reduces G, R, and G×R, thereby enhancing texture control and improving process optimization for fabricating SX-like HX structures via the L-PBF process.

権利情報:

• Creative Commons BY-NC-ND Attribution-NonCommercial-NoDerivs 4.0 International
  

キーワード: Hastelloy X, Laser powder bed fusion process, Substrate preheating, Microstructure, Texture, Stray grains

刊行年月日: 2026-01-20

出版者: Elsevier BV

掲載誌:

• Journal of Materials Research and Technology (ISSN: 22140697) vol. 41 p. 1974-1985

研究助成金:

• The Acquisition, Technology, and Logistics Agency (ATLA), Japan JPJ004596
• The Amada Foundation AF- 2022201-A3

原稿種別: 出版者版 (Version of record)

MDR DOI:

公開URL: https://doi.org/10.1016/j.jmrt.2026.01.142

関連資料:

その他の識別子:

連絡先:

更新時刻: 2026-02-16 17:22:12 +0900

MDRでの公開時刻: 2026-01-27 18:02:10 +0900