Abstract

The peculiarities of structure and phase formation in the 5 Ta–2 Ni–3 Al intermetallic system are studied in the paper. The TaNiAl, NiAl, Ni₂Al₃, and Ta phases are found in the alloy produced by self-propagating high-temperature synthesis (SHS). A transition layer with the composition of Ta₅₁Ni₂₀Al₂₉ about 1–2 μm thick is formed on the interface between the unreacted Ta particles and the TaNiAl phase. Remelting of the synthesized alloy at a temperature of about 3000°C leads to the formation of three structural components with the following compositions: Ta₈₅Ni₇Al₈, Ta₅₂Ni₂₀Al₂₈, and Ta₅₃Ni₂₅Al₂₂. X-ray analysis of the remelted alloy shows the presence of reflections that do not correspond to any of the known phases in the Ta–Ni–Al system. An alloy with a similar composition is synthesized by electrothermal explosion (ETE) under load. The synthesized alloy has a heterogeneous structure and multiphase composition of the surface layer which is similar to the alloy produced by SHS. The central region of the sample produced by ETE is similar to the structural and phase composition of the sample melted at temperature of 3000°C. The obtained data show the possibility of synthesizing in the Ta–Ni–Al system various phases with high Ta content (more than 50 at %).

中文翻译：

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Ta-Ni-Al体系中新的金属间相的形成

摘要

本文研究了5 Ta-2 Ni-3 Al金属间化合物体系的结构和相形成的特殊性。在通过自蔓延高温合成（SHS）生产的合金中发现了TaNiAl，NiAl，Ni ₂ Al ₃和Ta相。在未反应的Ta粒子与TaNiAl相之间的界面上形成过渡层，该过渡层的成分为Ta ₅₁ Ni ₂₀ Al ₂₉，厚度约为1-2μm。合成合金在约3000°C的温度下重熔会导致形成以下成分的三种结构成分：Ta ₈₅ Ni ₇ Al ₈，Ta ₅₂ Ni ₂₀ Al₂₈和Ta ₅₃ Ni ₂₅ Al ₂₂。重熔合金的X射线分析表明存在与Ta-Ni-Al系统中任何已知相都不对应的反射。负载下通过电热爆炸（ETE）合成具有相似成分的合金。合成合金具有与SHS生产的合金相似的表面层的非均质结构和多相组成。通过ETE生产的样品的中心区域类似于在3000°C的温度下熔化的样品的结构和相组成。获得的数据显示了在Ta-Ni-Al系统中合成高Ta含量（大于50 at％）的各种相的可能性。