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Microstructure, Tensile, and Creep Behaviors of Ti-22Al-25Nb (at.%) Orthorhombic Alloy with Equiaxed Microstructure

This article investigates the tensile and creep behaviors of the Ti-22Al-25Nb (at.%) alloy with equiaxed microstructure. The experimental results show that the equiaxed microstructures are formed by isothermal forging in the α(2) + B2 + O phase region, and then heat treating in α(2) + B2 + O and B2...

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Detalles Bibliográficos
Autores principales: Wang, Wei, Zeng, Weidong, Sun, Yaling, Zhou, Haixiong, Liang, Xiaobo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073622/
https://www.ncbi.nlm.nih.gov/pubmed/30036934
http://dx.doi.org/10.3390/ma11071244
Descripción
Sumario:This article investigates the tensile and creep behaviors of the Ti-22Al-25Nb (at.%) alloy with equiaxed microstructure. The experimental results show that the equiaxed microstructures are formed by isothermal forging in the α(2) + B2 + O phase region, and then heat treating in α(2) + B2 + O and B2 + O phase regions. The equiaxed particles are determined by isothermal forging and solution heat treating, and the acicular O phase is obtained by adjusting the aging temperature. The strengths of the alloy are sensitive to the thickness of the secondary acicular O phase. Increase in aging temperature improves strength and reduces the ductility. Deformation of the alloy mainly depends on the volume fraction and deformability of the B2 phase. During the high-temperature tensile deformation, the flow stress decreases with the increasing deformation temperature and increases with the increasing strain rate. The microstructure obtained by higher aging temperature (HT-840) has better creep resistance, due to the coarsening of the secondary acicular O phase.