滑移作为钛合金双相组织中的主要变形机制，研究其启动和传递机制，对于揭示钛合金组织对性能的影响机制具有重要意义。本项目基于原位SEM-EBSD加载实验和晶体学计算，对滑移启动和传递过程进行实时表征和分析，进而深入研究以下问题：（1）揭示Schmid因子、弹性模量和应力集中对滑移启动的综合作用，以及滑移在β相中的优先启动机制；（2）揭示Schmid因子、几何协调因子和应力集中对滑移传递的综合作用，以及相界上滑移传递方向对传递条件的影响；（3）揭示裂纹形核位置选择的晶体学条件，对比分析相界和晶界上裂纹形核的难易程度；（4）综合分析不同组织状态下的滑移启动和传递、裂纹形核和宏观塑性行为，揭示相含量和晶粒尺寸对裂纹形核与宏观塑性的影响机制。本项目一方面有望在钛合金组织-性能关系方面取得新的理论发现，从而为性能优化提供新思路；另一方面有望在钛合金变形机制方面取得新进展，进而丰富塑性变形理论。

Slip is the main plastic deformation mechanism of titanium alloy with a dual-phase microstructure. A fundamental understanding of the slip initiation and transfer mechanism is crucial to reveal the intrinsic relationship between the microstructure and mechanical property. Combining with crystallographic calculations, this project will carries out an in-situ SEM-EBSD observations and analyses on the slip initiation and transfer process during straining, which will contributes to an in-depth study on the following issues. (1) The combined influence of Schmid factor, elasticity modulus and stress concentration on the slip initiation, as well as the preferential slip initiation mechanism in the β phase. (2) The combined influence of Schmid factor, geometric compatibility factor and stress concentration on the slip transfer, as well as the effect of transfer direction on the transfer behavior at the phase interface. (3) The crystallographic criteria for crack nucleation site selection which is related to the slip initiation and transfer behavior. (4) The influence mechanism of phase content and grain size on the crack nucleation and plasticity. This project is expected to achieve some new theoretical findings on the intrinsic relationship between the microstructure and mechanical property, subsequently arousing a new strategy for optimizing the properties of titanium alloy. Meanwhile, it would make a new progress in the crystallographic criteria of deformation mechanism to improve the plastic deformation theory.