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

Abstract

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 °C increased significantly from 40.4 to 57.2 MPa, which is an increase of >40%. Even after heat exposure at 350 °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 Al11(Ce,Y)3 phase at 350 °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 Al11(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.

Keywords

• Al alloy
• Al–Ce
• Cerium
• Yttrium
• Microstructure
• Strengthening