Influence of solution temperature on eutectic structure and elevated-temperature mechanical properties of super-gravity solidified Al-Cu-Ce alloy

Abstract

The influence of solution temperature on microstructure and mechanical properties in super-gravity solidified Al-Cu-Ce alloy was investigated. Noted that the formation of eutectic Al₈CeCu₄ phase is able to affect the precipitation behavior. Both heterogeneous and homogeneous nucleation of the precipitates occur during aging, leading to the formation of disk-like precipitates (Al-Al₈CeCu₄ interface) and needle-like precipitates (grain interior), which contributed to the significant enhancement(~53% higher than the super-gravity solidified sample) of tensile strength of 204.1±3.8 MPa at 300 ℃. However, micro-cracks initiated preferentially in the vicinity of the eutectic colony boundaries mainly due to the brittleness of the spheroidized Al₈CeCu₄ phase, leading to a slight decrease in elongation.