Abstract High strain-hardening rates in equiatomic CrCoNi and other multi-principal element alloys have been attributed to deformation twinning. This work shows that small additions of Al and Ti to a CrCoNi alloy deactivate deformation twinning with only minor changes to uniform elongation and ultimate tensile strength. The initial microstructure is free of chemically ordered (Al,Ti)-rich precipitates after solutionizing and quenching. Tensile properties for the alloy are reported and compared to equiatomic CrCoNi, and the post-deformation microstructure is assessed. Density functional theory calculations indicate that energetically unfavorable Al-Al bonds may discourage shearing via partial dislocations, which are necessary for twinning to occur.

中文翻译：

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添加少量铝和钛使中等熵 CrCoNi 中的变形孪晶失活

摘要 等原子 CrCoNi 和其他多主元素合金的高应变硬化率归因于形变孪晶。这项工作表明，向 CrCoNi 合金中添加少量的 Al 和 Ti 可以使变形孪晶失活，而对均匀伸长率和极限拉伸强度的影响很小。固溶和淬火后，初始显微组织不含化学有序的富含 (Al,Ti) 的沉淀物。报告了合金的拉伸性能并与等原子的 CrCoNi 进行了比较，并评估了变形后的微观结构。密度泛函理论计算表明，能量上不利的 Al-Al 键可能会阻止通过部分位错进行剪切，而部分位错是孪晶发生所必需的。