Enhanced high temperature strength in near- eutectic Al-8Ce alloy through Y addition by gravity casting

In this study, the heat resistant Al-8Ce-xY (x = 0, 1, 2, and 3) alloys as designed and fabricated by gravity casting. The tensile strength of the alloys at room temperature increased with the Y addition from 117.5 to 142.7 MPa, and the tensile strength at 350 degrees C increased significantly from 40.4 to 57.2 MPa, which is an increase of >40%. Even after heat exposure at 350 degrees C for 200 h, the alloys still retain the morphology of the eutectic colony and hardness stable. The outstanding performance is primarily attributed to excellent heat stability of eutectic lamellar Al-11(Ce,Y)(3) phase at 350 degrees C and its volume fraction increased from 10.45 to 19.15% with Y additions from 0 to 3%. The increasing volume fraction of the eutectic Al-11(Ce,Y)(3) phase effectively improves the tensile strength of the alloys at ambient and high temperatures. Our work provides a new ternary Al-Ce-Y system which is a marvellous candidate for castable heat resistant Al alloys.