Analysis on microstructure and mechanical properties of Ti-47.5Al-3Nb-1.5Cr alloy through heat-treatment

• Published in: Journal of alloys and compounds 2022-07, Vol.908, p.164689, Article 164689
• Main Authors: Peng, Peng, Zhou, Shudong, Liu, Zijie, Pei, Xing, Gan, Lu, Xu, Yuanli, Zhang, Xudong, Ma, Zhikun, Wang, Jiatai
• Format: Article
• Language: English
• Subjects: A new TiAl alloys; Elongation; Heat treating; Heat treatment; Heat-treated; Mechanical properties; Microstructure; Microstructure evolution; Room temperature; Solid solutions; Solution strengthening; Tensile strength; Tensile tests; Titanium base alloys
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.164689

In order to study the effect of microstructure on mechanical properties of heat -treated Ti-47.5Al-3Nb-1.5Cr (at%.) samples, a heat treatment system was designed at 1573 K, 1623 K and 1673 K for 15 min, 30 min and 60 min. After the heat preservation, the samples were air-cooled. Among them, when the as-cast samples are keep at 1623 K for a period of time, the interlamellar spacing is refined. In addition, due to the heat treatment in the two-phase region, the elements are further diffused and more uniform in the sample. The room temperature tensile tests exhibits that the mechanical properties of the samples obtained by holding at 1623 K for 1 h and then air-cooling obtained the best improvement, the tensile strength and elongation at break from 372.54 MPa and 0.70% to 533.86 MPa and 1.04%. After analyzing the mechanical properties and structure of the alloy, it can be concluded that refining the interlamellar spacing and solid solution strengthening can effectively improve the elongation and tensile strength. ●Ti-47.5Al-3Nb-1.5Cr is designed by modifying elements based on the 4822 alloy.●Heat treatment route is obtained to improve the mechanical properties of alloy.●Relationship between heat treatment, microstructure and properties is clarified.