Non-isothermal crysta

Abstract

In the present work, thermal behavior of Al86Ni8Y6 and Al86Ni6Y4.5Co2La1.5 as-cast amorphous ribbons, corresponding milled ribbon particles and spark plasma sintered samples has been studied. Activation energies of crystallization at all transition temperatures of the samples were determined by Kissinger, Ozawa and Augis-Bennett equations. The first stage of crystallization for both the as-cast ribbons, related to formation of nanocrystalline FCC Al disappeared completely in case of the milled ribbon particles and consolidated samples. In comparison to as-cast ribbons, the onset of second stage crystallization with corresponding activation energies shifted to lower values in the milled ribbon particles; whereas the onset and peak temperatures of third stage crystallization and related activation energies shifted to higher values. Formation of higher amount of crystalline phases during sintering led to decrease in all transition temperatures and corresponding activation energies of bulk samples compared to that of the milled ribbon particles. © 2019 Elsevier B.V.