TY - JOUR
T1 - Microstructure, mechanical properties, and crystallization behavior of Zr-based bulk metallic glasses prepared under a low vacuum
AU - Churyumov, A. Yu
AU - Bazlov, A. I.
AU - Tsarkov, A. A.
AU - Solonin, A. N.
AU - Louzguine-Luzgin, D. V.
N1 - Funding Information:
This work was supported by the Ministry of Education and Science of the Russian Federation in the framework of the Program aimed to increase the competitiveness of the National University of Science and Technology “MISiS” (№ К2-2014-013 ), State Task to the Universities of the Russian Federation (Project № 11.1760.2014/K ), RFBR (Project 13-03-91330-NNIOa ) and by the World Premier International Research Center Initiative (WPI), MEXT , Japan.
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2016/1/5
Y1 - 2016/1/5
N2 - The present work is devoted to an investigation of the microstructure, deformation behavior and kinetics of crystallization of Zr-based glassy alloys produced in a low vacuum environment. The data obtained indicate that small additions of rare earth (RE) metals, such as Dy, Gd, Er, to a Zr62.5Cu22.5Fe5Al10 alloy are likely to suppress heterogeneous nucleation of impurities, and thus, increase the glass forming ability (GFA), which allows obtaining glassy ingots up to 5 mm diameter even under a low vacuum. The structure of the alloys consisted of a glassy matrix and a small fraction of RE oxides. The large difference between the enthalpies of the oxide formation of copper and RE elements is responsible for the reduction of copper concentration in the regions near the oxides. According to the kinetics parameters of crystallization, the highest thermal stability observed in a Gd-bearing alloy corresponds to its good GFA. The maximum compression strength was achieved in the alloy containing 0.5 at.% of Dy. At the same time, the optimal combination of strength and plasticity, with the fracture strength of 1890 MPa and the plastic deformation of 3.3%, was observed in the alloy containing 1 at.% of Gd. A finite element modeling (FEM) analysis showed that equiaxed oxide particles can prevent propagation of a single shear band and promote generation of multiple shear bands.
AB - The present work is devoted to an investigation of the microstructure, deformation behavior and kinetics of crystallization of Zr-based glassy alloys produced in a low vacuum environment. The data obtained indicate that small additions of rare earth (RE) metals, such as Dy, Gd, Er, to a Zr62.5Cu22.5Fe5Al10 alloy are likely to suppress heterogeneous nucleation of impurities, and thus, increase the glass forming ability (GFA), which allows obtaining glassy ingots up to 5 mm diameter even under a low vacuum. The structure of the alloys consisted of a glassy matrix and a small fraction of RE oxides. The large difference between the enthalpies of the oxide formation of copper and RE elements is responsible for the reduction of copper concentration in the regions near the oxides. According to the kinetics parameters of crystallization, the highest thermal stability observed in a Gd-bearing alloy corresponds to its good GFA. The maximum compression strength was achieved in the alloy containing 0.5 at.% of Dy. At the same time, the optimal combination of strength and plasticity, with the fracture strength of 1890 MPa and the plastic deformation of 3.3%, was observed in the alloy containing 1 at.% of Gd. A finite element modeling (FEM) analysis showed that equiaxed oxide particles can prevent propagation of a single shear band and promote generation of multiple shear bands.
KW - Differential scanning calorimetry
KW - Finite elements modeling
KW - Low vacuum
KW - Mechanical properties
KW - Structure
KW - Zr-based bulk metallic glasses
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U2 - 10.1016/j.jallcom.2015.09.003
DO - 10.1016/j.jallcom.2015.09.003
M3 - Article
AN - SCOPUS:84942693465
VL - 654
SP - 87
EP - 94
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -