高速弹丸冲击诱发TC4中绝热剪切带的微观结构  

Microstructure of Adiabatic Shear Bands in the TC4 Titanium Alloy Induced by High-Speed Projectile Impact

作　　者：杨珅[1] 张从林[1] 黄尉[1] 蔡杰[1] 关庆丰[1] 

机构地区：[1]江苏大学,江苏镇江212013

出　　处：《稀有金属材料与工程》2016年第9期2307-2312,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金委员会-中国民用航空局联合基金(U1233111)

摘　　要：利用弹丸高速冲击TC4钛合金靶板,采用透射电子显微镜(TEM)研究诱发的绝热剪切带(ASBs)附近及内部微观结构。ASBs附近区域微观结构的观察表明,ASBs边界容易成为诱发裂纹萌生的核心;ASBs附近积聚了很大的内应力,容易形成高密度的缠结位错、条带状位错胞等位错组态和应力诱发马氏体结构。ASBs内部微观结构的观察表明,ASBs为应力诱发结构,沿垂直ASBs的方向,越接近ASBs的中心部位,晶粒碎化越严重;在ASBs中没有观察到典型的动态再结晶(DRX)晶粒特征,观察结果不支持ASBs中发生DRX以及ASBs的发源与传播都和DRX有关这一传统观点;同时在ASBs中心区域出现了玻璃态的非晶结构。TC4 titanium alloy plates were impacted by projectile at a high speed. The microstructure changes inside and nearby the adiabatic shear bands（ASBs） were observed by transmission electron microscope（TEM）. The microstructure observation nearby the ASBs indicates that the boundaries of the ASBs may be the origin for the crack initiation. High stress is concentrated nearby the ASBs, and thus it is easy to form high density dislocation configurations（such as tangled dislocations and banded dislocation cells） and stress induced martensite. The microstructure observation inside the ASBs reveals that they are mainly induced by high stress. Along the direction vertical to the ASBs, the closer to the center of the ASBs, the more serious the grain fragmentation is. The typical characteristics of dynamic recrystallization（DRX） are not found in the ASBs; as a result, the present observations do not support the traditional viewpoints that DRX occurs in the ASBs and the origin and dissemination of the ASBs are related to the DRX. Besides, amorphous is also found in the center of the ASBs.

关 键 词：TC4钛合金 高速弹丸冲击 绝热剪切带(ASBs) 微观结构 

分 类 号：TG146.23[一般工业技术—材料科学与工程]