Influence of Cooling Rate on Phase Transformation of a α+β Titanium Alloy

Abstract:

Effect rules of cooling rate on phase transformation and microstructure of a α+β titanium alloy were studied by thermal dilatometer method. Specimens under different cooling rates from 0.05°C/s to 2.5°C/s were analyzed by using X-ray diffraction (XRD), optical micrograph (OM) and Vickers micro-hardness. The results showed that the starting temperature of β to α phase transformation gradually decreased with the increase of cooling rate. The finishing temperature of β to α phase transformation firstly decreased and then increased with the increase of cooling rate. The typical lamellar structures were observed under the cooling rates from 0.05°C/s to 0.2°C/s. The layer thickness of α phase became thinner and the precipitation content of α phase reduced under the cooling rate of 0.5°C/s. The α phase was fine acicular and the precipitation content of α phase reduced obviously under the cooling rate of 2.5°C. The effect rule of cooling rate on micro-hardness was that the value of micro-hardness firstly decreased and then increased with the cooling rate increasing.

• Periodical: Materials Science Forum (Volume 849)
• Pages: 327-331
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.849.327
• Online since: March 2016
• Authors: Yue Fei, Xin Nan Wang, Guo Qiang Shang, Jing Li, Li Wei Zhu, Zhi Shou Zhu
• Keywords: Cooling Rate, Microstructure, Phase Transformation, Titanium Alloy

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