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与Al3Sc类似,Al30Dy7Zr3化合物也具有L12结构,有望利用其来提高Al合金的高温强度.因此,了解Al-Dy-Zr体系富Al角的相关系极为重要.本文将C15_Laves相处理成计量比化合物,重新优化了Al-Dy二元相图;采用包含16个原子的特别准随机结构(SQS_16)来模拟Dy1-xZrx(x=0.25,0.5,0.75)hcp_A3固溶体,通过第一原理方法计算了其0 K下的混合焓.根据该计算结果以及文献中评估的相图对Dy-Zr二元系进行了热力学优化;最后,结合3个边界二元系的热力学描述,将第一原理计算与相图计算(CALPHAD)方法相耦合优化了Al-Dy-Zr三元系富Al角相图.计算的相关系数与实验结果符合得很好,证明该热力学描述是合理的.
Similar to Al3Sc, the Al30Dy7Zr3 compound also has the L12 structure, which is expected to be used to improve the high temperature strength of the Al alloy.Therefore, it is very important to understand the relationship between the Al-rich Al angle and the Al-Dy-Zr alloy.In this paper, The Al-Dy binary phase diagram was re-optimized. The solid-state Dy1-xZrx (x = 0.25,0.5,0.75) hcp_A3 solid solution was simulated with a special quasi-random structure containing 16 atoms (SQS_16) K, and the enthalpy of mixing. The thermodynamic optimization of Dy-Zr binary system was carried out based on the calculated results and the phase diagrams evaluated in the literature. Finally, combining the thermodynamic description of the three boundary binary systems, CALPHAD method was used to optimize the phase diagram of the Al-Dy-Zr ternary Al-enriched phase. The calculated correlation coefficient is in good agreement with the experimental results, which proves that the thermodynamic description is reasonable.