Evolution of the Microstructure and Lamellar Orientation of a β-Solidifying γ-TiAl-Based Alloy during Hot Compression

Metals

Jun Shen¹  Kai Zhu¹  Shoujiang Qu¹  Aihan Feng¹  Jingli Sun² 

[1] School of Materials Science and Engineering, Tongji University, Shanghai 201804, China;Shanghai Spaceflight Precision Machinery Institute, Shanghai 201600, China;

关键词: γ-TiAl-based alloy;    microstructure;    lamellar orientation;    electron backscattered diffraction;   

DOI  :  10.3390/met8060445

来源: DOAJ

【 摘 要 】

A type of advanced γ-TiAl-based alloy called β-solidifying γ-TiAl has elicited remarkable research interest in the last few decadesbecause of its excellent workability and homogeneous microstructures. Thermomechanical treatments are widely applied to this alloy to obtain fine duplex microstructures. To investigate the deformation behavior and microstructure evolution of Ti-44Al-4Nb-1.5Cr-0.5Mo-0.2B alloy, we conducted a series of hot compression tests at a temperature of 1473 K and a strain rate of 0.01 s−1. Scanning electron microscopy, electron backscattered diffraction, and transmission electron microscopy were performed to analyze the crystal orientation and microstructures of the alloy. During compression at 1473 K, β/B2→γ transition and α2/γ lamellae→γ+β/B2 transition occurred simultaneously, which increased the content of the γ phase and decreased the content of the α2 phase. The lamellar colonies exhibited distinct anisotropy, which could affect their hot deformation behavior. The colonies that remained after compression had strong texture components.

【 授权许可】

Unknown