The 400℃ Isothermal Section Of The Phase Diagram Of La-Ni-Si Ternary System

The 400 C isothermal section of the phase diagram of La-Ni-Si ternary system has been investigated by X-ray powder diffraction, DTA, optical microscopy and scanning electron microscopy techniques. The phase diagram consists of 35 single-phase regions , 78 two-phase regions and 47 three-phase regions.The 35 single-phase regions areThe 78 two-phase regions areThe 47 three-phase regions areAt 400 C , the maximum solid solubility of Ni in LaSi2 about 4at.%; the maximum solubilities of Si in Ni,LaNi5, La2Ni7 and La2NiSi are about 9at. %, 8.33at. % , 3at. % and 5at. %, respectively. And the single-phase region 1,1 and K1, are limit solid solution. They are expressed as, LaNi11.6-9.5Si1.4-3.5, LaN i8.8-8.4Si4.2-4.6,LaNi7.8-6.5S i5.2-6.5, respectively. Neither La in Ni nor in Si is showed evidence of solid solubility. Any other solubility in the phases has not been observed.