Nano-Devitrification and Structural Evolution of Rapidly Solidified Amorphous Al-TM (Cu-Co)-Y (at.%) Alloy

Activation energies and other kinetic parameters of primary crystallization of Al86Cu6Co2Y6 (at.%) amorphous alloy describing the mechanism was determined. Melt spinning on a child copper wheel was used to prepare the Al86Cu6Co2Y6 (at. %) amorphous ribbons. The ribbons at as-spun and annealed conditions were studied by optical microscopy (OM), differential scanning calorimetry (DSC), X-ray diffraction and field emission scanning electron microscopy (FESEM). The kinetic parameters of the crystallization process were determined by Kissinger and Moynihan methods at non-isothermal condition. Crystallization mechanism was studied using the Johnson–Mehl–Avrami equation. According to the average value of Avrami exponent (2.065±0.16), the primary crystallization process is conducted by 3D diffusional growth with decreasing rate. The α-Al nanoparticles below 50 nm in size distributed evenly in the glassy matrix and intermetallic phases (Al3Y, AlCu3 and Al11Y3) were formed during the first and second stages of crystallization, respectively.