纵向冲击压缩下LY12铝合金圆环的塑性失稳
发布时间：2019-01-05 08:02
【摘要】：通过对铝合金圆环的纵向冲击压缩研究发现,一定条件下在试件的宏观塑性硬化阶段会出现明显的应力降过程。为揭示此应力降的发生机制,对润滑、细磨、粗磨3种端面粗糙条件下,外径、内径和高度比值为6∶3∶2的LY12铝合金圆环进行系统的Hopkinson压杆纵向冲击实验。结果表明:应力降主要发生在较大的应变和较高的应变率条件。进一步对实验样品的金相观察发现:应力降产生的内在机制为绝热剪切带的形成和发展,此现象是一种动态塑性失稳的过程。以上结果为金属材料在冲击条件下绝热剪切带产生的研究提供了参考。
[Abstract]:By studying the longitudinal impact compression of aluminum alloy rings, it is found that under certain conditions, obvious stress drop process will occur in the macroscopic plastic hardening stage of the specimens. In order to reveal the mechanism of the stress drop, the longitudinal impact experiments of LY12 aluminum alloy rings with 6:3:2 ratio of outer diameter, inner diameter and height were carried out under the conditions of lubrication, fine grinding and rough grinding. The results show that the stress drop mainly occurs in the larger strain and higher strain rate condition. It is found that the internal mechanism of stress drop is the formation and development of adiabatic shear band, which is a dynamic plastic instability process. The above results provide a reference for the study of adiabatic shear band generation of metallic materials under impact conditions.
【作者单位】： 中国科学技术大学中国科学院材料力学行为和设计重点实验室;
【基金】：国家自然科学基金项目(11272304,11472264)
【分类号】：TG146.21
，
本文编号：2401501
[Abstract]:By studying the longitudinal impact compression of aluminum alloy rings, it is found that under certain conditions, obvious stress drop process will occur in the macroscopic plastic hardening stage of the specimens. In order to reveal the mechanism of the stress drop, the longitudinal impact experiments of LY12 aluminum alloy rings with 6:3:2 ratio of outer diameter, inner diameter and height were carried out under the conditions of lubrication, fine grinding and rough grinding. The results show that the stress drop mainly occurs in the larger strain and higher strain rate condition. It is found that the internal mechanism of stress drop is the formation and development of adiabatic shear band, which is a dynamic plastic instability process. The above results provide a reference for the study of adiabatic shear band generation of metallic materials under impact conditions.
【作者单位】： 中国科学技术大学中国科学院材料力学行为和设计重点实验室;
【基金】：国家自然科学基金项目(11272304,11472264)
【分类号】：TG146.21
，
本文编号：2401501
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