Refining mechanism and elevated-temperature mechanical properties of Al-Ce alloys solidified under super gravity field

We reported that the enhanced elevated-temperature mechanical property of Al-Ce alloy could be obtained by solidification under super-gravity field. The refinement of eutectic Al11Ce3 is detected, which can be ascribe to the enhancement of mass transfer under super-gravity field, affecting the nucleation rate and inhibiting the growth of eutectic phase for this irregular Al-Ce eutectic system. Interestingly, the refined eutectic Al11Ce3 is thermally stable even up to 400 degrees C thermal exposure without obvious coarsening, contributing to the enhancement of elevated-temperature mechanical properties (-125.0 & PLUSMN; 9.1 MPa at 300 degrees C), which is -74.8% higher than that solidified under normal gravity field (-71.5 & PLUSMN; 0.6 MPa). The refinement of eutectic Al11Ce3 with higher number density also contribute to the stress dispersion, the crack prefer to propagate through the eutectic colony, leading to the transformation of fracture mode from brittle to ductile.