Stability of crystallographic texture in laser powder bed fusion: Understanding the competition of crystal growth using a single crystalline seed

Takuya Ishimoto, Koji Hagihara, Kenta Hisamoto, Takayoshi Nakano*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

62 Scopus citations

Abstract

In metal additive manufacturing, crystallographic orientation control is a promising method for tailoring the functions of metallic parts. However, despite its importance in the fabrication of texture-controlled functional parts, the stability of the crystallographic texture is not widely discussed. Herein, the crystallographic texture stability under laser powder bed fusion was investigated. Two methodologies were employed. One is that a laser scanning strategy was alternately changed for a specific number of layers. The other is a “seeding” experiment in which single-crystalline substrates with controlled crystallographic orientations in the building (z-) direction and the xy-plane (perpendicular to the building direction) were used as the starting substrate. The transient zone width, where the crystallographic orientation was inherited from the layer beneath, was analyzed to evaluate the texture stability. The crystallographic direction of the seed within the xy-plane, rather than the building direction, determined the transient zone width, i.e., the texture stability. In particular, the texture in the newly deposited portion was stable when the laser scanning direction matched the <100> orientation in the underneath layer, otherwise the crystal orientation switched rapidly, such that the <100> orientation was parallel to the scanning direction. Interestingly, the crystallographic orientation along the building direction in the underneath layer hardly impacted the stability of the texture. Therefore, for the first time, it has been clarified that the <100> orientation in the scanning direction, rather than the building direction, was preferentially stabilized, whereas the orientation in the other directions secondary stabilized.

Original languageEnglish
Article number102004
JournalAdditive Manufacturing
Volume43
DOIs
StatePublished - 2021/07

Keywords

  • Crystal growth
  • Crystallographic texture
  • Laser powder bed fusion
  • Single crystal
  • Stability

ASJC Scopus subject areas

  • Biomedical Engineering
  • General Materials Science
  • Engineering (miscellaneous)
  • Industrial and Manufacturing Engineering

Fingerprint

Dive into the research topics of 'Stability of crystallographic texture in laser powder bed fusion: Understanding the competition of crystal growth using a single crystalline seed'. Together they form a unique fingerprint.

Cite this