Eleti Rajeshwar R, Klimova Margarita, Tikhonovsky Mikhail, Stepanov Nikita, Zherebtsov Sergey
Laboratory of Bulk Nanostructured Materials, Belgorod National Research University, Pobeda 85, Belgorod, Russia, 308015.
National Science Center "Kharkov Institute of Physics and Technology" NAS of Ukraine, Kharkov, 61108, Ukraine.
Sci Rep. 2020 Aug 6;10(1):13293. doi: 10.1038/s41598-020-70298-2.
Ti-rich body-centered cubic (BCC, β) high-entropy alloys having compositions TiZrHfNbTa, TiZrHfTaSn, and TiZrHfTaSn (in at%) were designed using bond order (Bo)-mean d-orbital energy level (Md) approach. Deformation mechanisms of these alloys were studied using tensile deformation. The alloys showed exceptionally high strain-hardening and ductility. For instance, the alloys showed at least twofold increment of tensile strength compared to the yield strength, due to strain-hardening. Post-deformation microstructural observations confirmed the transformation of β to hexagonal close packed (HCP, α') martensite. Based on microstructural investigation, stress-strain behaviors were explained using transformation induced plasticity effect. Crystallographic analysis indicated transformation of β to α' showed strong variant selection (1 1 0)//(0 0 0 1), and [1 - 1 1]//[1 1 - 2 0].
采用键序（Bo）-平均d轨道能级（Md）方法设计了成分分别为TiZrHfNbTa、TiZrHfTaSn和TiZrHfTaSn（原子百分比）的富钛体心立方（BCC，β）高熵合金。通过拉伸变形研究了这些合金的变形机制。这些合金表现出极高的加工硬化和延展性。例如，由于加工硬化，这些合金的抗拉强度与屈服强度相比至少提高了两倍。变形后的微观结构观察证实了β相向六方密排（HCP，α'）马氏体的转变。基于微观结构研究，利用相变诱发塑性效应解释了应力-应变行为。晶体学分析表明，β相向α'相的转变表现出强烈的变体选择（1 1 0）//（0 0 0 1），以及[1 -1 1]//[1 1 -2 0]。
