Moskovskikh Dmitry, Vorotilo Stepan, Buinevich Veronika, Sedegov Alexey, Kuskov Kirill, Khort Alexander, Shuck Christopher, Zhukovskyi Maksim, Mukasyan Alexander
National University of Science and Technology MISiS, Moscow, 119049, Russia.
KTH Royal Institute of Technology, 114 28, Stockholm, Sweden.
Sci Rep. 2020 Nov 16;10(1):19874. doi: 10.1038/s41598-020-76945-y.
Simultaneously hard and tough nitride ceramics open new venues for a variety of advanced applications. To produce such materials, attention is focused on the development of high-entropy ceramics, containing four or more metallic components distributed homogeneously in the metallic sublattice. While the fabrication of bulk high-entropy carbides and borides is well established, high-entropy nitrides have only been produced as thin films. Herein, we report on a newel three-step process to fabricate bulk high-entropy nitrides. The high-entropy nitride phase was obtained by exothermic combustion of mechanically-activated nanostructured metallic precursors in nitrogen and consolidated by spark plasma sintering. The fabricated bulk high-entropy nitride (HfNbTaTiZr)N demonstrates outstanding hardness (up to 33 GPa) and fracture toughness (up to 5.2 MPa∙m), significantly surpassing expected values from mixture rules, as well as all other reported binary and high-entropy ceramics and can be used for super-hard coatings, structural materials, optics, and others. The obtained results illustrate the scalable method to produce bulk high-entropy nitrides with the new benchmark properties.
同时兼具硬度和韧性的氮化物陶瓷为各种先进应用开辟了新途径。为了生产此类材料，人们将注意力集中在高熵陶瓷的开发上，这种陶瓷在金属亚晶格中含有四种或更多均匀分布的金属成分。虽然块状高熵碳化物和硼化物的制造已相当成熟，但高熵氮化物仅制成了薄膜。在此，我们报道了一种制备块状高熵氮化物的新型三步法。通过机械活化的纳米结构金属前驱体在氮气中进行放热燃烧获得高熵氮化物相，并通过放电等离子烧结进行固结。制备的块状高熵氮化物(HfNbTaTiZr)N表现出出色的硬度(高达33 GPa)和断裂韧性(高达5.2 MPa∙m)，大大超过了混合法则的预期值，以及所有其他已报道的二元和高熵陶瓷，可用于超硬涂层、结构材料、光学等领域。所得结果说明了一种可扩展的方法，能够生产具有新基准性能的块状高熵氮化物。
