Abstract：Titanium alloy obtained lamellar microstructure (LM) and bimodal microstructure (BM) microstructures by the controlling of heat treatment parameters. Moreover, the tensile deformation behavior and effects of microstructure type on low cycle fatigue (LCF) behavior were investigated. The results indicate that TC21 alloy with coarse LM microstructure occur ductile rupture, since the annealing twins change the crystal orientation of part lamellar, and increase the plastic deformation degree before rupture. Dislocation multiplication and movement in αp phase and lathlike second α phase is the dominant factor for the deformation behavior of TC21 alloy with BM microstructure. The αp phase in BM microstructure can hinder the LCF crack propagation direction. Moreover, the absorbed energy of crack propagation can be increased by the αp phase. Therefore, the LCF lives were enhanced because of αp phase. The resistance for LCF crack propagation of αp phase in BM microstructure can be increased by the precipitation of α2 phase, since the harder α2 phase precipitated in the αp phase during thermal exposure (TE). For the BM+TE specimens, the crack mainly passes through the αp phase with “bypass”, while, for the BM specimens, the crack passes through the αp phase with “cutting”. Therefore, the LCF lives of Ti600 alloy after thermal exposure become longer because that the α2 phase precipitated in αp phase.
刘晓斌，翟羽佳，于腾. 显微组织对钛合金强韧性的影响[J]. , 2018, 25(3): 25-30.
LIU Xiao- bin,ZHAI Yu- jia,YU Teng. Effects of microstructure on strengthening- toughening of titanium alloys. , 2018, 25(3): 25-30.
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2018, Vol. 25 
