Solid-liquid reaction in the Si3N4-AlN-Y2O3 system under 1 MPa of nitrogen

The melting behaviors of selected compositions in the Si3N4-AlN-Y2O3 system were determined under 1 MPa of nitrogen. The phase diagrams of the ternary and their binary systems are presented. The lowest melting composition of the ternary system contains 15 mol% Si3N4, 25 mol% AlN, and 60 mol% Y2O3 and has a melting temperature of 1650 degrees C. The binary eutectic compositions and temperatures are 15 mol% Si3N4 and 85 mol% Y2O3 at 1720 degrees C, and 20 mol% AlN and 80 mol% Y2O3 at 1730 degrees C.