Melting Ranges of Zr–Si–ZrB2–ZrSi2–MoSi2 and Zr–Si–HfB2–HfSi2–MoSi2 Heterophase Systems.

Autor: Zinovyeva, M. V., Sanin, V. V., Pogozhev, Yu. S., Astapov, A. N., Levashov, Ye. A.
Zdroj: Inorganic Materials: Applied Research; Mar2021, Vol. 12 Issue 2, p271-279, 9p
Abstrakt: 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 Tm0 to 1460–1560°C and in the complete melting temperature Tmelt to 1480–1670°C. Addition of the HfB2–HfSi2–MoSi2 powders influenced only slightly the Tm0 value (1390–1430°C), but resulted in the increase in Tmelt 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. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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