【摘要】 为了探明TC4钛合金室温下的滞后回弹效应,采用万能试验机进行了不同预应变和不同加载速率的滞后回弹实验;为了揭示滞后回弹变化规律的微观机理,采用OM和TEM对微观组织进行表征。结果表明:TC4钛合金经过室温塑性变形卸载后尺寸继续变化,具有明显的滞后回弹效应。随着预应变以及加载应变率的提高,滞后回弹应变(TDSS)的绝对值均呈现指数增长。组织分析表明,"流线型"光镜组织、位错塞积以及孪晶组织的演变与滞后回弹变化规律正相关。更多还原

【Abstract】 The time-dependent springback and anelastic behavior of TC4 titanium alloy were investigated as functions of time, prescribed strain and loading strain rate by universal testing machine. In order to infer its basis, the microstructures of samples under different loading conditions were examined by optical microscope(OM) and transmission electron microscope(TEM). The results reveal that the absolute values of time-dependent springback strain(TDSS) accumulating in 10 h both present exponential growth, as the prescribed strain and loading strain rate rise. The OM and TEM results show that the evolutions of "streamline" microstructure, dislocation pile-up, and deformation twin have positive correlation with the change law of TDSS.更多还原