Document Type : Research Paper
School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Tehran, Iran
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 (2.0650.16), 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.