动态加载条件下冷轧5A06铝合金显微组织研究

以80%冷变形5A06铝合金为试验材料,利用分离式Hopkinson压杆加载装置(SHPB)进行动态冲击压缩试验,探讨高速形变响应规律,分析其动态力学行为;利用透射电子显微镜技术观察位错界面结构的变化,分析位错界面的高速形变响应。结果表明:预变形5A06铝合金在塑性变形前已发生绝热剪切行为,致使合金强度下降;初始位错界面成为高速形变过程中位错滑移的主要障碍;冲击前后,位错界面结构方向由与轧向平行演变为与轧向呈10°~20°夹角,位错界面间距由0.25μm演变为0.10~0.15μm。

Microstructure evolutions for cold rolled 5A06 aluminum alloy under dynamic compression

5A06 aluminum alloy with 80% reduction after cold rolled was selected as experimental material. Dynamic compression performance of alloy under high speed deformation were obtained by a split Hopkinson pressure bar,and the evolution of dislocation boundaries structure were characterized through transmission electron microscopy. The high-speed deformation response of dislocation boundaries in the commercially 5 A06 aluminum alloy was launched. The results show that pre-deformed 5 A06 aluminum alloy appears adiabatic shear behaviors before the plastic deformation at high strain rate compression,and the shear localization induces the alloy strength decreases. The initial dislocation boundary becomes a major obstacle to dislocation slipping under high-speed compression. After compressions,the initial dislocation boundaries paralleled to rolling direction rotate with 10°-20°,and the average boundary spacing evolves from 0.25 μm to 0.10-0.15μm.