Rapid hardening response of ultra-hard Ti-6Al-2Sn-4Zr-6Mo alloy produced by laser powder bed fusion

Huizhi Peng, Shun Wu, Wen Hao Kan, Samuel Chao Voon Lim, Yuman Zhu, Aijun Huang

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)


Post heat treatment is essential for additively manufactured alloys to eliminate residual stress and in some cases further improve mechanical performance. This study systematically investigated the hardening response of a Ti-6Al-2Sn-4Zr-6Mo alloy processed by laser powder bed fusion (LPBF) to a one-step heat treatment. The results revealed significant hardening at both 500 °C and 650 °C. Most notably, an ultra-high peak-hardness of 563VHN was achieved within 5 mins of heat treatment at 650 °C due to a unique martensite-decomposed α+β microstructure consisting of alternating long β laths that are ∼5 nm thick and α laths that are ∼35 nm thick, and within the α laths are also short β laths that are ∼2 nm thick with an ∼11 nm inter-spacing. The influence of both types of β laths on the α lath thickness was established and related to the ultra-high hardness observed, which provides new insight for the design of new metastable LPBF-processed Ti alloys.

Original languageEnglish
Article number115209
Number of pages6
JournalScripta Materialia
Publication statusPublished - 15 Mar 2023


  • Isothermal heat treatments
  • Laser powder bed fusion
  • Martensitic phase transformation
  • Titanium alloy

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