Abstract

We investigate the melting ranges of the base Zr–Si mixture (eutectic composition) depending on the content of the heterophase powder component in the ZrB₂–ZrSi₂–MoSi₂ and the HfB₂–HfSi₂–MoSi₂ systems in the amount of 30–90 wt % obtained by self-propagating high-temperature synthesis (SHS). The range of the melting point of the Zr–Si mixture was 1420–1440°C; addition of the ZrB₂–ZrSi₂–MoSi₂ SHS powders resulted in an increase of the melting onset temperature T_m0 to 1460–1560°C and in the complete melting temperature T_melt to 1480–1670°C. Addition of the HfB₂–HfSi₂–MoSi₂ powders influenced only slightly the T_m0 value (1390–1430°C), but resulted in the increase in T_melt to 1510–1550°C. The X-ray phase analysis shows that the remelted samples contain the following phases: ZrB₂/HfB₂, ZrSi₂/HfSi₂, MoSi₂, and Si; here, the number of phases was directly proportional to the SHS powder content in the Zr–Si mixture. The ingots are characterized by a homogeneous structure consisting of the silicon matrix and ZrSi₂/HfSi₂ and MoSi₂ grains, with inclusions of ZrB₂/HfB₂.

中文翻译：

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Zr–Si–ZrB 2 –ZrSi 2 –MoSi 2和Zr–Si–HfB 2 –HfSi 2 –MoSi 2异相系统的熔融范围

摘要

我们根据ZrB ₂ -ZrSi ₂ -MoSi ₂和HfB ₂ -HfSi ₂ -MoSi ₂系统中异相粉末组分的含量，研究了基础Zr-Si混合物（共晶成分）的熔化范围，其中通过自蔓延高温合成（SHS）获得30–90 wt％。Zr-Si混合物的熔点范围为1420–1440°C；加入的ZrB的₂ -ZrSi ₂ -MoSi ₂ SHS粉末导致增加的熔化起始温度的Ť _M0至1560至60年℃，并在完全熔化温度Ť_熔体到1480–1670°C。HfB ₂ -HfSi ₂ -MoSi ₂粉末的添加仅对T _m0值（1390–1430°C）产生轻微影响，但导致T_熔体增加至1510–1550°C。X射线相分析表明，重熔样品含有以下相：ZrB ₂ / HfB ₂，ZrSi ₂ / HfSi ₂，MoSi ₂和Si。在这里，相数与Zr-Si混合物中SHS粉末含量成正比。锭的特征在于由硅基质和ZrSi ₂ / HfSi ₂和MoSi组成的均质结构_2个晶粒，包含ZrB ₂ / HfB ₂。