A New Mechanism of Dynamic Phase Transformations in An Isothermal Forged Beta-Gamma Intermetallic Alloy

Zhengang Zhang; Shoujiang Qu; Guorong Cui; Aihan Feng; Jun Shen; Daolun Chen

doi:10.3390/ma12172787

A New Mechanism of Dynamic Phase Transformations in An Isothermal Forged Beta-Gamma Intermetallic Alloy

Materials (Basel). 2019 Aug 30;12(17):2787. doi: 10.3390/ma12172787.

Authors

Zhengang Zhang¹, Shoujiang Qu², Guorong Cui³, Aihan Feng¹, Jun Shen^{1

4}, Daolun Chen⁵

Affiliations

¹ School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
² School of Materials Science and Engineering, Tongji University, Shanghai 201804, China. qushoujiang@tongji.edu.cn.
³ School of Materials Science and Engineering, Harbin Institute of Technology, Weihai 264209, China. cuiguorong@hitwh.edu.cn.
⁴ College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen 518060, China.
⁵ Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON M5B 2K3, Canada. dchen@ryerson.ca.

Abstract

A new mechanism of dynamic phase transformations of α₂ ↔ γ in an isothermally forged γ-TiAl-based alloy that occur simultaneously during a short-term exposure at 1000 °C is identified in this study. In the heating process, γ phase significantly decreases through a phase transformation of γ → α₂, while new γ lamellae are precipitated in the interior of equiaxed grains of α₂ phase through a phase transformation of α₂ → γ. The reasons for the presence of these two inverse phase transformations α₂ ↔ γ occurring simultaneously are discussed.

Keywords: microstructure; phase transformation; precipitation; titanium aluminide.

Abstract

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