Система Hf-Re-Si при 1000°С.

The interaction of the components in the ternary system Hf-Re-Si was investigated by X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The isothermal section of the phase diagram at 1000°C was constructed in the full concentration range. The limits of solubility of Si in the binary compounds Hf₅Re₂₄ and HfRe₂ were found to be 11 and 16 at.%, respectively. The existence of three ternary compounds was confirmed and their crystal structures were refined: HfReSi₂ (ZrCrSi₂-type structure, space group Pbam, a=9.1271(3) Å, b=10.0356(4) Å, c=8.0708(3) Å), HfReSi (ZrNiAl-type structure, space group P-62m, a=6.9240(2) Å, c=3.3890(1) Å) and -phase Hf_9+xRe_4-xSi (Hf₉Mo₄B-type structure, space group P6₃/mmc, a=8.5835(12) Å, c=8.7135(13) Å). The character of the interaction between the components in the Hf-Re-Si system and related ternary systems is briefly discussed. [ABSTRACT FROM AUTHOR]