Shock compression and spallation of a eutectic high-entropy alloy (HEA) AlCoCrFeNi_2.1 with lamellar structure are investigated via plate impact loading with free-surface velocity measurements. The as-cast and postmortem samples are characterized with transmission electron microscopy, electron back-scatter diffraction and scanning electron microscopy. An accurate Hugoniot equation of state is determined. After shock compression to ∼12 GPa, both the L1₂ and B₂ phases retain their ordered structures. Dense dislocations in the {111} slip planes, stacking faults and deformation twins are found in the L1₂ phase, along with fewer dislocations in the {110} slip bands in the B₂ phase. Shock-induced deformation twinning within the L1₂ phase of this HEA is observed as a new deformation mechanism under various loading conditions. For spallation, both ductile and brittle damage modes are observed. The micro voids and cracks prefer to nucleate at the phase boundaries chiefly, then in the B₂ phase. Under similar shock stress, the spall strength of AlCoCrFeNi_2.1 HEA is about 40% higher than those of other reported dual-phase HEAs due to the high stability of its semi-coherent phase boundaries.

共晶高熵合金 (HEA) AlCoCrFeNi _{2的冲击压缩和剥落。具有层状结构的图1}通过具有自由表面速度测量的板冲击载荷进行研究。通过透射电子显微镜、电子背散射衍射和扫描电子显微镜对铸态和死后样品进行表征。确定了准确的 Hugoniot 状态方程。在冲击压缩至~ 12 GPa 后，L1 ₂和B ₂相均保持其有序结构。_{在L1 2}相中发现{111}滑移面中的致密位错、层错和变形孪晶，而在B ₂中的{110}滑移带中的位错较少阶段。_{该 HEA 的 L1 2}相内的冲击引起的变形孪晶被观察为在各种加载条件下的新变形机制。对于散裂，可观察到韧性和脆性损伤模式。微孔洞和裂纹倾向于主要在相界成核，然后在B ₂相中。在相似的冲击应力下，AlCoCrFeNi _{2的剥落强度。1}由于其半相干相边界的高度稳定性，HEA 比其他报道的双相 HEA 高约 40%。