|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Deformation and Transitions at Interfaces
||Investigation of Dislocation Activities during Slip Transmission across Alpha/Beta Interface in Ti-alloy Using Microscopic Phase-Field
||Pengyang Zhao, Chen Shen, Ju Li, Michael Mills, Yunzhi Wang
|On-Site Speaker (Planned)
Plastic deformation of alpha/beta Ti-alloy is largely controlled by the interplay between the inter-phase interfaces and dislocation motion, of which the underlying mechanisms still remain unclear. Using the recently developed microscopic phase-field model, we study the dynamic process of dislocation-mediated slip transmission across alpha/beta interfaces. Quantitative simulation is achieved by incorporation of the generalized stacking fault (GSF) energy surfaces obtained from ab initio calculations and matching two GSFs at alpha/beta interface with experimentally revealed Burgers orientation relationship. A continuous dislocation flux driven by external stress (accounting for dislocation sources in real materials) is considered to glide across alpha-beta-alpha sandwich configuration and the simulation result reveals successive pile-up, reaction, transmission, and storage events. In particular, mechanisms proposed previously based on experimental characterizations are examined quantitatively and new mechanisms of slip transmission assisted by Shockley partials are proposed based on the current simulations. A coarse-grained dislocation density based description is also proposed.