Effects of microstructure on fatigue crack propagation behavior in a bi-modal TC11 titanium alloy fabricated via laser additive manufacturing

• DOI: 10.1016/j.jmst.2018.10.031
• Publication Date: 2018-10-30T04:05:08Z
• Authors: Yafei Wang; Rui Chen; Xu Cheng; Yanyan Zhu; Jikui Zhang; Huaming Wang
• Keywords: Equiaxed crystals; Titanium alloy

Abstract In this study, the crack propagation behaviors in the equiaxed and equiaxed-columnar grain regions of a heat-treated laser additive manufacturing (LAM) TC11 alloy with a special bi-modal microstructure are investigated. The results indicate that the alloy presents a special bi-modal microstructure that comprises a fork-like primary α (αp) phase surrounded by a secondary α colony (αs) in the β phase matrix after the heat treatment is completed. The samples demonstrate a fast crack growth rate with larger da/dN values through the equiaxed grain sample versus across the equiaxed-columnar grain sample at low ΔK values (