Article ID Journal Published Year Pages File Type
1627448 Journal of Alloys and Compounds 2006 5 Pages PDF
Abstract

A Zr55.9Cu18.6Ta8Ni10Al7.5 bulk metallic glass (BMG) composite with an amorphous matrix reinforced by micro-scale particles of Ta-rich solid solution was prepared by copper-mold casting. The crystallization kinetics of the BMG composite was investigated under isothermal conditions by differential scanning calorimetry (DSC) and was modeled by the Johnson–Mehl–Avrami equation. It was found that the crystallization process follows three distinct stages with different Avrami exponents. The average Avrami component was about 2.5 at the initial and final stages, implying a mechanism of diffusion-controlled three-dimensional growth with a constant nucleation rate. However, the Avrami exponent was higher than 4 in the middle stage, indicating that the crystallization involved a transient nucleation process with an increasing nucleation rate. The different mechanisms in various stages of crystallization were tentatively discussed from a structural point of view.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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