Abstract: During the solution treatment of TC18 titanium alloy in the single β phase region, the black fleck formed and acted as a heterogeneous microstructure. Many characterization methods, such as optical microscope (OM), scanning electron microscope (SEM), electron back-scattered diffraction (EBSD), and so on, were used to make a precise characterization on the black fleck. Meanwhile, some additional heat treatments were carried out for revealing the formation mechanism of black fleck. The results showed that the massive precipitation of acicular α phase made the β grain exhibit as a black fleck morphology, and the black fleck existed as a large and accumulated morphology. During solution treatment, accompanying a slow cooling rate in the center region of the TC18 titanium alloy bar, the formation of subgrain and remnant dislocation in the non-completed recrystallized β grain promoted the precipitation of acicular α phase.
1 Lutjering G, Williams J C. Titanium, 2nd ed., Springer, America,2007. 2 Zeng W D, Zhou Y G. Materials Science and Engineering A,1999,260,203. 3 吕逸帆,孟祥军,李士凯.稀有金属材料与工程,2008,37(增刊3),544. 4 赵子博,王清江,刘建荣,等.金属学报,2015,51(5),561. 5 Banerjee D, Williams J C. Acta Materialia,2013,61,844. 6 孙继锋,黄爱军,杨义.热处理,2015,30(5),49. 7 Huang S, Ma Y J, Zhang S L, et al. Metallurgical and Materials Tran-sactions A,2018,49,6390. 8 Shao H, Shan D, Wang K, et al. Journal of Alloys and Compounds,2019,797,10. 9 张利军,周中波,常辉,等.中国有色金属学报,2013,23(8),2206. 10 Gao X X, Zeng W D, Zhao Q, et al. Journal of Alloys and Compounds,2017,727,346. 11 Wang K, Li M Q. Materials Science and Engineering: A,2014,613,209.
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2020, Vol. 34 
