Sample Abstract for the 7th Latin-American Conference on Nanostructuredand Metastable Materials

AMORPHOUS QUANTIFICATION OF VIT105 METALLIC GLASS ALLOYBY OPTICAL LIGHT MICROSCOPY

N. D. Campos Neto1,*,#, F. S. Pereira1, F. H. Santa Maria1, F. C. Daneze1, M. F. Oliveira1, C. J. Parrish2

1Solidification Laboratory, Materials Engineering Department, University of São Paulo, Brazil

2Boeing Research & Technology, Boeing, Brazil

#Corresponding author:

Metallic glasses, or amorphous metals, are metallic materials with no crystalline structure, i.e., their atomic structure is amorphous, without long range ordering, although short, or first neighborhood, ordering can be observed [1,2]. The study was conducted for Vit 105 bulk metallic glass alloy commercialized by Materion [3]. The purpose of this study was to evaluate the influence of oxygen contamination on GFA (Glass Forming Ability) of the alloy measuring the amorphous fraction by changing the content of oxygen and the sample diameter produced by arc melting injection casting. The alloy was received from the manufacturer with 180 ppm of oxygen and the samples were contaminated using CuO to reach the nominal 500 ppm, 800 ppm and 1250 ppm of Oxygem. The sample sizes was 2, 3, 4, 5 and 6 mm in diameter. The samples was etched using a solution of 10%HF and 90%HNO3by immersing the sample polished surface for 5 seconds [4]. The quantification process followed the modified ASTM E-1245 [5]. Statistical data treatment showed that the operator bias was not a significative factorand the 3 different operators measurements could be calculated as repetitions, showing that there are a correlation between Oxygen and sample size and that GFA is inversely proportional to Oxygencontent. By multiple linear regression it was possible to determine experimentally an equation that calculate and predict the amorphous content (GFA) of Vit 105 bulk metallic glass alloy in dependence of Oxygen content and sample size with R2 of 65%.

Keywords: Bulk metallic glass, Amorphous Quantification, Vit 105

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[2] M. Miller, P. Liaw, Bulk Metallic Glasses: an overview (2008) Springer, 237 p., ISBN 978-0-387-48920-9.

[3] Materion Corporation, Bulk Metallic Glasses Data Sheet, 2016. accessed in 11/21/2016 at 11:00pm.

[4] G. Petzow, Metallographische, Keramographisches und Plastographisches Aetzen, Borntrager (1994) p. 134.

[5] ASTM E1245-03: Standard Practice for Determining the Inclusion or Second-Phase Constituent Content of Metals by Automatic Image Analysis, 2003.