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 Al _63 Cu _25 Fe _12 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 Al _63 Cu _25 Fe _12 alloy contains icosahedral quasicrystal phase ( I -phase), λ − Al _13 Fe _4 phase, β − Al _0.5 Fe _0.5 phase and Al _2 Cu _3 phase. The addition of Ce is confirmed to lead to grain refinement, formation of the Al _13 Ce _2 Cu _13 phase, disappearance of the λ − Al _13 Fe _4 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 Al _63 Cu _25 Fe _12 alloy by ∼20%. The contribution of Ce will render better prospects for the application of Al-Cu-Fe-Ce materials.

Keywords

• Al-Cu-Fe-Ce alloy
• Quasicrystal
• Microstructure
• Thermal expansion properties