Effect of Ni on the Thermal Stability of Al-Ce Alloys

Aluminum–Cerium (Al-Ce) alloys have emerged as promising heat-resistant aluminum alloys for high-temperature applications. The addition of another element to increase the volume fraction of second phases in Al-Ce alloy can further improve the mechanical properties. In this study, the influences of nickel (1-5 wt.%) on the microstructure and thermal stability of the Al-10Ce alloy were investigated. The as-cast microstructure of the Al-Ce-Ni alloy ingot consists of α-Al, Al11Ce3, and Al3Ni phases. Moreover, the presence of Ni increases the hardness of the Al-Ce alloy. To evaluate thermal stability, the alloys were exposed to a temperature of 400°C for up to 96 hours. The results show that the hardness of the alloy decreased after exposure, primarily attributed to the instability of the Al3Ni phase at elevated temperatures.