高应变率下TC4及TC9钛合金的动态断裂

 报导了由短脉冲激光引起的应力波加载及电炮驱动Mylar膜平面飞片碰撞TC4、TC9钛合金靶的实验及数值计算研究结果。由回收靶样品的金相分析表明：在电炮驱动飞片碰撞及由激光引起的应力波加载所造成的应变率分别在10⁶ s^-1左右及10⁷ s^-1以上两种情形下，TC4、TC9钛合金的层裂特性都是以微孔洞的成核、增长、汇合为特征的韧性断裂。运用一维流体弹塑性动力学程序进行数值研究表明：成核增长NAG模型在一定程度上可以用来描述高应变率下TC4、TC9钛合金的损伤破坏特性。

DYNAMIC FRACTURE OF TC4 AND TC9 TITANIUMALLOY UNDER HIGH STRAIN RATES

The experimental and numerical simulation results of dynamic failure of TC4 and TC9 titanium alloys under shock loadings induced by short pulse duration laser beam and electric gun drived Mylar plane flyer impacting the specimen is reported in this paper. The detail metallurgical analysis of recovered specimen indicates that for both loading conditions, the strain rate about 10⁶ s^-1 by electric gun drived flyer impacting target and the strain rate over 10⁷ s^-1 by short pulse duration laser beam loading, the failure and fracture of TC4 and TC9 titanium alloys are all ductile in the course of microvoid nucleation, growth and coalescence. The numerical investigation by one dimensional code SSS shows that to some extent the nucleation and growth (NAG) damage model can be used to describe the failure of TC4 and TC9 titanium alloys under high strain rates.