Effects of Aging Temperature on the Microstructure and Mechanical Properties of a Ti₂AlNb Based Alloy

Abstract:

Effects of aging temperature on microstructure and room temperature mechanical properties of solid solution treated Ti₂AlNb based alloy have been investigated. The experimental results showed that after solution treatment and subsequently aging at different temperatures, all the alloys had β/B2, α₂ and O three phases, which formed a typical bimodal microstructure with primary α₂/O particles and acicular O precipitates dispersing within β/B2 matrix. With increasing the aging temperature, the acicular O precipitates decreased in amount but slightly increased in dimension; the particle α₂/O phase did not change in amount but varied in structure, which changed into a core-shell morphology with an α₂ core and a rim-O shell, and the rim-O shell was thickened; the change of microstructure led to the decrease in room temperature strength while slight improvement in plasticity. During the tension test, the cracks prefered to propagate along the prior β/B2 grain boundaries which were weaken by the necklace primary α₂/O particles.

• Periodical: Materials Science Forum (Volume 849)
• Pages: 368-375
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.849.368
• Online since: March 2016
• Authors: Yi Zhou, Jing Xia Cao, Xu Huang, Bao Wang, Guang Bao Mi
• Keywords: Aging Treatment, Mechanical Properties, Microstructure, Ti₂AlNb

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