Crystallization and grain growth behavior of Zr65CU27.5Al7.5 metallic glass

The phase transition by crystallization and a grain growth behavior of a Zr 65Cu27.5Al7.5 metallic glass were examined as a function of isothermal anne aling time at various temperatures. At the initial stage of crystallization . a metastable Zr(Al,Cu) phase is observed, in addition to a main phase of Zr2Cu, below the annealing temperature of 730 K. The formation of Zr (Al,Cu ) may be attributed to the strong chemical affinity between Al and Zr. The gain growth rate for Zr Cu is extremely low comparing with that for a Zr65C u35 binary metallic glass. Therefore, the strong chemical affinity between ill and Zr seems to contribute to the retardation of nucleation and grain g rowth of the crystalline phases. The grain growth kinetics can be described by lug(dD/dt(g)) = log(k/3) - 2 log D where D is the measured grain size, t(g) the grain growth time and k the constant. The activation energy Q for grain growth is calculated to be 165 kJ mol(-1), (C) 2001 Elsevier Science B.V. All rights reserved.