Effect of the addition of cerium on the microstructure evolution and thermal expansion properties of cast Al-Cu-Fe alloy

Abstract

The evolution of the microstructure and the variation in the thermal expansion properties of the Al63Cu25Fe12 alloy by the addition of different amounts of cerium (Ce) are investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). Herein, a new series of quasicrystal alloys containing Ce are prepared. Results revealed that the Al63Cu25Fe12 alloy contains icosahedral quasicrystal phase (I-phase), λ − Al13Fe4 phase, β − Al0.5Fe0.5 phase and Al2Cu3 phase. The addition of Ce is confirmed to lead to grain refinement, formation of the Al13Ce2Cu13 phase, disappearance of the λ − Al13Fe4 phase. Furthermore, the area fraction of the I-phase in the alloy is confirmed to reach the maximum value, and the linear expansion coefficient of the alloy is the lowest due to the addition of Ce of up to 1 at%. The addition of Ce can reduce the linear expansion coefficient of the Al63Cu25Fe12 alloy by ∼20%. The contribution of Ce will render better prospects for the application of Al-Cu-Fe-Ce materials.