THE ISOTHERMAL SECTION OF THE PHASE-DIAGRAM OF THE TERNARY-SYSTEM AL-SN-Y AT ROOM-TEMPERATURE

The isothermal section of the phase diagram of the ternary system Al-S n-Y (65 at.% Y or less) at room temperature was investigated by X-ray powder diffraction, differential thermal analysis, optical microscopy, electron microscopy, electron spectrum and electron probe microanalys is techniques. The section at room temperature consists of ten single- phase regions, 18 two-phase regions and nine three-phase regions. The single-phase region pi (Al3Sn9Y8) in this section at roam temperature is a new ternary intermetallic compound. It was found that no single p hase Al4Y exists in the binary Al-Y. The other eight single-phase regi ons in the section correspond to binary intermetallic compounds in the Systems Al-Sn, Al-Y and Sn-Y. The range of all homogeneous phase fiel ds of terminal solid solution is too small to be observed at room temp erature.