Effect of microvoids on microplasticity behavior of dual-phase titanium alloy under high cyclic loading (I): Crystal plasticity analysis
(1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University,Xi’an 710072, China;
2. Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024, China)
2. Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024, China)
Abstract: A crystal plasticity finite element (CPFE) model was established and 2D simulations were carried out to study the relationship between microvoids and the microplasticity deformation behavior of the dual-phase titanium alloy under high cyclic loading. Results show that geometrically necessary dislocations (GND) tend to accumulate around the microvoids, leading to an increment of average GND density. The influence of curvature in the tip plastic zone (TPZ) on GND density is greater than that of the size of the microvoid. As the curvature in TPZ and the size of the microvoid increase, the cumulative shear strain (CSS) in the primary α, secondary α, and βphases increases. Shear deformation in the prismatic slip system is dominant in the primary α phase. As the distance between the microvoids increases, the interactive influence of the microvoids on the cumulative shear strain decreases.
Key words: crystal plasticity; dual-phase Ti alloy; microvoids; high cyclic loading; cumulative shear strain; geometrically necessary dislocation