Hot deformation behavior and constitutive model of TC18 alloy during compression

• Published in: Rare metals Vol. 33; no. 4; pp. 383 - 389
• Main Authors: Jia, Bao-Hua, Song, Wei-Dong, Tang, Hui-Ping, Wang, Zhi-Hua, Mao, Xiao-Nan, Ning, Jian-Guo
• Format: Journal Article
• Language: English
• Published: Springer Berlin Heidelberg Nonferrous Metals Society of China 01.08.2014; Springer Nature B.V
• Subjects: Biomaterials; Chemistry and Materials Science; Constitutive relationships; Deformation; Electronics; Energy; Flow stress; Links; Materials Engineering; Materials Science; Mathematical models; Metallic Materials; Nanoscale Science and Technology; Physical Chemistry; Strain rate; Yield strength; 压缩过程; 合金; 应变速率; 本构模型; 流动应力; 温度范围; 热变形行为; 电子万能试验机; Hot deformation; Constitutive model; TC18 titanium alloy; Strain rate
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-014-0328-x

The hot deformation behavior of TC18 alloy at strain rates ranging from 1 × 10-4 to 1 x 10-2 s-1 and temperatures ranging from 25 to 800 ℃ was studied using a WDW-300 electronic universal testing machine. The relationships between true flow stress decreases with stress and true strain show that the increase of temperature and increases as strain rate increases. The effect of strain rate on the flow stress becomes pronounced at higher temper- atures. At room temperature, the river pattern characteristic of brittle fracture and the dimple pattern typical of ductile fracture are found to exist in different regions of fracture surfaces of the samples. An improved constitutive rela- tionship is proposed to accurately describe the flow stress of TC18 by considering the effect of strain. And a micro- scopic model is also deduced which can link the physical mechanisms to the macroscopic experimental results. A good agreement is obtained between the predictions of the microscopic model and the results of the macroscopic experiment.