Influence of Small Content Elements Additions on the Glass Forming Ability of Zr-based Bulk Metallic Glasses Alloys

Nelson Delfino De Campos Neto,Catherine Jane Parrish,Wesley Marques De Paula,Flavio Soares Pereira,Marcelo Falcão De Oliveira

doi:10.1590/1980-5373-mr-2017-1088

Nelson Delfino De Campos Neto, Catherine Jane Parrish + Show 3 more

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https://doi.org/10.1590/1980-5373-mr-2017-1088

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Abstract

The present work reports investigation on the Glass Forming Ability (GFA) of Zr-based Bulk Metallic Glasses (BMG’s) by microalloying with early transition metals. GFA was measured as the amorphous fraction formed in samples with different diameters using optical microscopy (OM) and image analysis techniques. Samples with the highest GFA had their oxygen content measured in a Leco RO-400. This study shows that additions of Molybdenum or Iron in a Zr48Cu(48-x)Al4Mx (M = Mo or Fe) alloys resulted in a minor GFA improvement, but far from the results reported in the literature with Nb additions in this system. Niobium microalloying to a Zr62Cu15.5Al10Ni(12.5-x)Nbx and (Zr55Cu30Al10)100-xNbx alloys have a deleterious effect on the GFA. Oxygen measurements of (Zr55Cu30Al10)99Nb1 and Zr62Cu15.5Al10Ni12.4Nb0.1 alloys have shown similar oxygen content, indicating that oxygen was not a limiting factor on this study. The amorphous fraction quantification from OM image analysis maintains the same fraction ratio from the heat released at the crystallization event from heating DSC analysis.

Highlights

The application of Bulk Metallic Glasses (BMG) as engineering materials is the goal of many research teams spread around the globe
The Glass Forming Ability (GFA) was measured as the amorphous fraction formed in samples with different diameters by image analysis of optical microscopy and correlated with differential scanning calorimetry (DSC) and scanning electron microscopy (SEM)
The present study performed on Zr48Cu(48-x)Al4Mx, where M = Fe or Mo, showed that the addition of this elements decrease the alloy’s GFA

Summary

Introduction

The application of Bulk Metallic Glasses (BMG) as engineering materials is the goal of many research teams spread around the globe. In order to use BMGs in structural applications the research groups are investigating ways of increasing the Glass Forming Ability (GFA) and ductility of such alloys. The literature shows that GFA and ductility can be both improved with the use of minor addition of elements, or microalloying technique[5]. Microalloying has improved the GFA of many BMG systems by stabilizing the amorphous phase[5], removing deleterious elements from the glass matrix[6] or altering its crystallization kinetics[7]. The ductility of several alloys was increased by the compositional change[8,9] or by the formation of a second phase[10,11] embedded in the amorphous matrix

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