Softening and hardening on a Zr-based bulk metallic glass induced by nanosecond laser surface melting

Yang Jiao, Emmanuel Brousseau, Koji Kosai, Alexander J.G. Lunt, Jiwang Yan, Quanquan Han, Hanxing Zhu, Samuel Bigot, Weifeng He

Research output: Contribution to journalArticlepeer-review

Abstract

The study reported here confirms that laser surface melting (LSM) can be employed to modify the hardness and the shear banding behaviour of bulk metallic glasses (BMGs). More specifically, by conducting LSM operations on the Zr-based Vitreloy 105 BMG in ambient atmosphere using a nanosecond laser, it was found that surface hardening can be achieved, in addition to the well-known surface softening effect. Besides, it was found that the presence of compressive residual stress and an increased introduction of crystalline precipitates accompanied LSM-induced surface hardening. On the contrary, tensile residual stress and a reduced fraction of crystalline precipitates were observed for a softened surface post-LSM. Finally, differences in shear-banding mechanisms were detected near the surface of the laser irradiated regions. More specifically, overall reduced serrated flow but important surface shear bands events were observed following the LSM-based introduction of compressive residual stress. In contrast, more pronounced serrated flows and the likely distribution of shear banding activity well beneath the irradiated BMG surface was promoted when LSM resulted in the introduction of tensile residual stress.

Original languageEnglish
Article number140497
JournalMaterials Science and Engineering A
DOIs
Publication statusAccepted/In press - 2020

Keywords

  • Bulk metallic glass
  • Hardness
  • Laser surface melting
  • Shear banding behaviour
  • Vitreloy 105

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Softening and hardening on a Zr-based bulk metallic glass induced by nanosecond laser surface melting'. Together they form a unique fingerprint.

Cite this