Second phases of rapidly solidified AlFeCrZrVSi alloy and their thermal stabilities

The rapidly solidified powder of AlFeCrZrVSi aluminum alloy was prepared using multi-stage atomization and consolidated by hot-extrusion, the evolution of microstructure of the extruded materials during thermal exposure was studied with optical microscope, X-ray diffraction and transmission electron microscope (TEM). The results show that the majority of dispersions present in the as-extruded alloy are metastable Al₁₂ (Fe, Cr, V)₃Si, which has excellent thermal-dynamical stability and coarsening resistance; the coarsening rate-controlling process of the Al₁₂ (Fe, Cr, V)₃Si phase is considered to be diffusion of Fe atom along grain boundaries instead of bulk diffusion of Fe atom. Project supported by the Key Program of the 8th Five-year Plan of China and the National Advanced Materials Commitee of China Synopsis of the first author Xiao Yude, doctoral student, born in 1969, majoring in rapidly solidified heat-resistant alloys.