An alternative aluminum casting alloys for high-temperature applications

Aluminum alloys are desirable for automotive and aerospace industries due to their lightweight, outstanding castability and excellent mechanical properties. However, one of the major drawbacks of aluminum alloys is that it does not retain their mechanical properties at high temperature. The addition of alloying elements to aluminum alloys can fill this gap. Many studies have attempted to find new aluminum-based alloys having a thermal stability. It was reported that eutectic Al-Ni and Al-Ce alloys can fulfill these requirements. The objective of this study is to investigate the microstructure and hardness of Al-Ni and Al-Ce alloys and compared to the presently used Al-Si alloys. The thermal stability of the alloys was investigated through the hardness after high-temperature exposure. The specimens were exposed in a furnace at 500 °C for up to 360 hours. The results revealed that the hardness of Al-Si, Al-Ni and Al-Ce alloys were reduced by 35.51%, 28.36% and 19.98%, respectively after the exposure. Regarding this finding, it can be implied that the Al-Ce eutectic is the most thermally stable.