Quantitative analysis on microstructure evolution of Ti-6Al-2Zr-2Sn-2Mo-1.5Cr-2Nb alloy during isothermal compression

• Published in: Rare metals 2015-09, Vol.34 (9), p.625-631
• Main Authors: Gao, Jun, Li, Miao-Quan, Li, Xiao-Di, Zhang, Dong, Xue, Jian-Rui, Jiang, Xue-Qi, Zhang, Chao-Yue, Liu, Lu-Yang
• Format: Article
• Language: English
• Subjects: alloy; Flow; Biomaterials; Chemistry and Materials Science; Compression tests; Crack propagation; Deformation; Deformation effects; Energy; Grain growth; Grain size; Materials Engineering; Materials fatigue; Materials Science; Mechanical properties; Metal fatigue; Metallic Materials; Microstructure; Morphology; Nanoscale Science and Technology; Phase transitions; Phases; Physical Chemistry; Process parameters; Quantitative analysis; Reduction; Scanning electron microscopy; Softening; Strain rate; stress; Gra; Temperature; Thermal simulators; Ti-6Al-2Zr-2Sn-2Mo-1.5Cr-2Nb; Titanium alloys; Titanium base alloys
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-015-0522-5

Isothermal compression tests of Ti-6Al-2Zr-2Sn-2Mo-1.5Cr-2Nb alloy were conducted at a Gleeble-1500 simulator in deformation temperature range of 1103–1243K, strain rate range of 0.01–5.00 s-1and height reduction range of 50 %–70 %. The effects of processing parameters on morphology, grain size and contents of a and b phases were discussed based on the quantitative microstructure examination, and the detailed explanation was shown. The results show that b transformed matrix will obviously grow up at higher deformation temperature or lower strain rate because of low grain growth activation energies. The content of a phase will decrease at higher deformation temperature or higher strain rate due to the phase transformation. Some elongated a or b grains exist at higher strain rate, implying that the dominant softening mechanism is dynamic recovery. The effect of height reduction on b transformed matrix is negligible, but the height reduction has some effects on the morphology of primary a phase.