Cyclic deformation and lattice strain distribution of high Nb containing TiAl alloy. Issue 14 (21st September 2020)

• Record Type: Journal Article
• Authors: Ding, Jie; Shi, Shan; Dong, Zhili; Lin, Junpin; Ren, Yang; Wu, Xiaodong; Chang, Hui; Zhou, Lian
• Is Part Of: Materials science and technology. Volume 36:Issue 14(2020)
• Page Start: 1507
• Page End: 1515
• Publication Date: 2020-09-21
• Subjects: TiAl alloys -- low cycle fatigue -- cyclic stress–strain behaviour -- recrystallization -- phase transformation -- fracture behaviour; Materials science -- Periodicals; Microstructure -- Periodicals; Metallurgy -- Periodicals; 620.1105
• DOI: 10.1080/02670836.2020.1795994
• Languages: English
• ISSNs: 0267-0836

Abstract

Abstract : Low cycle fatigue of lamellar TiAl with 8.5 at.-%Nb was studied with a total strain amplitude of 0.28% at three temperatures: room temperature, 750°C and 900°C. At room temperature, the material exhibited cyclic hardening and the fracture mode was mainly interlamellar. At 750°C and 900°C, the material showed cyclic softening and the fracture mode was translamellar. The lattice strain in γ phase was almost tensile and larger tensile lattice strain in γ phase seems detrimental. Besides, the opposite direction of {201}γ and {100}α2 lead to crack propagation along α2 /γ interfaces. B2/βo phase always suffered compressive lattice strain in the tests. The destruction of lamellar microstructure was the reason for colony refinement at 750°C and 900°C.