Static and shock compression studies of eutectic high-entropy alloy AlCoCrFeNi2.1 to ultrahigh pressures

作者：Kento Katagiri, Sara J. Irvine, Anirudh Hari, Ryosuke Kodama, Norimasa Ozaki, Takayoshi Sano, Jie Ren, Wuxian Yang, Wen Chen, Matthew P. Clay, Andrew D. Pope, Seth Iwan, Leora E. Dresselhaus‐Marais, Yogesh K. Vohra · 发表于：Journal of Applied Physics · 年份：2024 · DOI：10.1063/5.0192103 · 被引用次数：5 · 研究领域：High Entropy Alloys Studies、High-pressure geophysics and materials、High-Temperature Coating Behaviors

The high-entropy alloy with composition AlCoCrFeNi2.1, additively manufactured with the laser powder-bed fusion technique, has a far-from-equilibrium BCC/FCC eutectic nanolamellar structure. We studied the high-pressure response of this alloy under both static compression and high-strain rate shock compression. The response to static compression using a diamond anvil cell was studied at pressures up to 302 GPa with synchrotron x-ray diffraction at the advanced photon source. The high-pressure FCC-only phase of the EHEA previously observed by Pope et al. [AIP Adv. 13, 035124 (2023)] is found to be stable up to the highest pressure achieved in this study with a volume compression of V/V0 = 0.587 at ambient temperature. The shock experiments were performed by using GEKKO XII lasers at the Institute of Laser Engineering, Osaka University. The principal Hugoniot equation-of-state of the EHEA was measured up to a pressure of 515 GPa and a compression of V/V0 = 0.613. Additionally, the thermal equation of state of the EHEA was measured up to 6.2 GPa and 1623 K using a large-volume Paris–Edinburgh cell to obtain the temperature dependence of bulk modulus and thermal expansion coefficients. The melting temperature for EHEA AlCoCrFeNi2.1 at a pressure of 5.6 GPa was measured to be 1648 ± 25 K. These results can be used to refine stochastic (or special) quasi-random structure (SQS) models for high-pressure high-temperature behavior of high-entropy alloys.