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Mechanical Properties of Amorphous Al85Ni10La5 Alloy by Indentations Zhihui Zhang, Leonardo Ajdelsztajn, Yizhang Zhou, Enrique J. Lavernia Dept of Chemical Engineering and Materials Science, University of California, Davis, CA 95616 ABSRACT Indentation techniques have been carried out to study the mechanical behavior of amorphous Al85Ni10La5 alloy powders produced by inert gas atomization. The present work reveals that this amorphous alloy undergoes a three-stage crystallization process in the temperature range of 250°C ~ 390°C, with a glass transition temperature of approximately 259°C. In this study, the influence of devitrification on mechanical response was investigated via indentation of the Al85Ni10La5 alloy powders annealed at various temperatures, for instance, at temperatures well below or close to glass transition (235°C, 245°C, 250°C), and well above glass transition (283°C). Moreover, the microstructure evolution and the formation of nanoscale crystallites were studied using TEM and XRD. The influence of devitrification on the indentation response was characterized, paying particular attention to shear band formation and variations in hardness. The hardening behavior was analyzed on the basis of a rule-of-mixtures approach by treating the partially crystallized alloy as a nanocomposite. 1 INTRODUCTION Since the Al-TM-R (TM-transition metal, R-rare earth metal) amorphous alloys were first studied [1, 2], Al-based (>80 at%) amorphous alloys have attracted considerable interest over the past decade due to their high specific strength. For example, it has been reported [3] that the fracture strength of the Al-based amorphous alloys may reach around 1000 MPa. Although various compositions of the Al-based amorphous alloys have been formulated thus far, synthesis of the Al-based amorphous alloys has been largely limited to gas atomized powders (

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