Microstructural effects on the spall failure of 7085 aluminum alloy
Microstructural effects on the spall failure of 7085 aluminum alloy
复制标题
DOI：
10.1016/j.msea.2023.144674
复制
发表时间：
2023-02
期刊：
影响因子：
--
通讯作者：
Dung-Yi Wu;C. Miao;C. DiMarco;D. Mallick;K. Ramesh;T. Hufnagel
中科院分区：
文献类型：
--
作者：
Dung-Yi Wu;C. Miao;C. DiMarco;D. Mallick;K. Ramesh;T. Hufnagel
设计抗剥落铝合金需要了解动态载荷作用下的主动破坏机制。然而，从传统的板撞击碎片实验中获得足够的数据来研究这些机制是耗时和昂贵的。本文采用高通量激光驱动微飞片冲击技术，将Al7085-T711铝合金的剥落破坏与微观组织联系起来。通过在四种冲击速度下进行测试，我们观察了从初期碎裂到完全碎裂的全部行为。Al7085-T711的剥落强度随应变速率和峰值冲击应力的增加而增加，这在铝合金中是典型的情况。对回收样品的检测表明，早期的片状空洞主要在Al7Cu2Fe第二相颗粒处产生。为了进一步探索微观组织对剥落破坏的影响，我们在500℃下对一些试样进行了退火，增加了铝的晶粒尺寸，同时保留了Al7Cu2Fe颗粒，这对剥落强度的影响很小。另一方面，在600℃固溶去除Al7Cu2Fe第二相颗粒后，晶粒强度显著提高。研究结果表明，Al7085-T711的剥落破坏主要是由于Al7Cu2Fe第二相颗粒的存在，消除这些颗粒可以提高工业合金的抗剥落能力。
Designing aluminum alloys for spall resistance requires an understanding of the active failure mechanisms under dynamic loading. However, it is time-consuming and expensive to obtain sufficient data to investigate these mechanisms from conventional plate impact spall experiments. Here we use a high-throughput laser-driven micro-flyer plate impact technique to connect the spall failure of aluminum alloy Al7085-T711 to its microstructure. By conducting tests at four impact velocities, we observe the full range of behaviors from incipient spall to complete spall failure. The spall strength of Al7085-T711 increases with both increasing strain rate and peak shock stress, as is typically the case in aluminum alloys. Examination of recovered samples indicates that incipient spall voids initiate primarily at Al7Cu2Fe second-phase particles. To further explore the effect of microstructure on spall failure, we annealed some specimens at 500 °C to increase the aluminum grain size while retaining the Al7Cu2Fe particles, which had only a minor effect on spall strength. Solutionizing at 600 °C to eliminate the Al7Cu2Fe second-phase particles, on the other hand, increases the spall strength significantly. Our results suggest that spall failure of Al7085-T711 is dominated by the presence Al7Cu2Fe second-phase particles, and that eliminating these particles could result in improved spall resistance of commercial alloys.