Experimental investigation and thermodynamic assessment of the Al-Ca-Y ternary system

The experimental investigation and thermodynamic assessment of the Al-Ca-Y ternary system were carried out in this work. The isothermal section of the Al-Ca-Y ternary system at 673 K and 873 K was determined by using equilibrated alloys, combined with scanning electron microscopy, electron probe micro-analysis and powder X-ray diffractometry. Phase transition temperatures were measured by differential scanning calorimetry analysis. A certain range of solubility was detected between Al2Ca and Al2Y in this work, the maximum solid solubility of Y in Al2Ca was 11.9 at.% and that of Ca in Al2Y was 12.6 at.%. According to the thermodynamic data of binary systems in the literature and the ternary experimental data from this work and the literature, the Al-Ca-Y ternary system was optimized and a set of self-consistent thermodynamic parameters was obtained. Calculated phase equilibria were consistent with the experimental results.