Mechanical properties of bulk metallic glasses and composites

2007 ◽  
Vol 22 (2) ◽  
pp. 285-301 ◽  
Author(s):  
J. Eckert ◽  
J. Das ◽  
S. Pauly ◽  
C. Duhamel
Keyword(s):  
Mechanical Properties ◽  
Metallic Glasses ◽  
Shear Bands ◽  
Bulk Metallic Glasses ◽  
Second Phase ◽  
Matrix Composites ◽  
Future Directions ◽  
Glassy Alloys ◽  
Spatially Inhomogeneous ◽  
Glass Matrix Composites

The development of bulk metallic glasses and composites for improving the mechanical properties has occurred with the discovery of many ductile metallic glasses and glass matrix composites with second phase dispersions with different length scales. This article reviews the processing, microstructure development, and resulting mechanical properties of Zr-, Ti-, Cu-, Mg-, Fe-, and Ni-based glassy alloys and also considers the superiority of composite materials containing different phases for enhancing the strength, ductility, and toughness, even leading to a “work-hardening-like” behavior. The morphology, shape, and length scale of the second phase dispersions are crucial for the delocalization of shear bands. The article concludes with some comments regarding future directions of the investigations of spatially inhomogeneous metallic glasses.

Correlation between the Enhanced Plasticity of Glassy Matrix Composites and the Volume Fraction, Size and Intrinsic Mechanical Property of Reinforcements

2014 ◽  
Vol 783-786 ◽  
pp. 1967-1970
Author(s):  
Z.H. Chu ◽  
Hidemi Kato ◽  
Guo Qiang Xie ◽  
D.R. Yan ◽  
Guang Yin Yuan
Keyword(s):  
Mechanical Properties ◽  
Metallic Glasses ◽  
Volume Fraction ◽  
Shear Bands ◽  
Ex Situ ◽  
Glassy Matrix ◽  
Matrix Composites ◽  
Micro Scale ◽  
Fraction Size

In recent years, bulk metallic glasses (BMGs) have received considerable attention due to their unique mechanical properties. However, the deformation of BMGs is highly localized in a few shear bands so that many of them exhibit poor plasticity. As such, more and more researchers have focused on improving the plasticity by in-situ or ex-situ introducing of nanoor micro-scale crystalline phases into the metallic glassy matrix in order to formation of multiple shear bands.

Bulk Metallic Glasses

2008 ◽  
Vol 604-605 ◽  
pp. 229-238
Author(s):  
Marcello Baricco ◽  
Tanya A. Başer ◽  
Gianluca Fiore ◽  
Rafael Piccin ◽  
Marta Satta ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Shear Bands ◽  
Bulk Metallic Glasses ◽  
Rapid Quenching ◽  
Second Phase ◽  
Research Activity ◽  
Long Time ◽  
Geometrical Constraints

Rapid quenching techniques have been successfully applied since long time for the preparation of metallic glasses in ribbon form. Only in the recent years, the research activity addressed towards the synthesis of bulk metallic glasses (BMG), in form of ingots with a few millimetres in thickness. These materials can be obtained by casting techniques only for selected alloy compositions, characterised by a particularly high glass-forming tendency. Bulk amorphous alloys are characterised by a low modulus of elasticity and high yielding stress. The usual idea is that amorphous alloys undergo work softening and that deformation is concentrated in shear bands, which might be subjected to geometrical constraints, resulting in a substantial increase in hardness and wear resistance. The mechanical properties can be further improved by crystallisation. In fact, shear bands movement can be contrasted by incorporating a second phase in the material, which may be produced directly by controlled crystallisation. Soft magnetic properties have been obtained in Fe-based systems and they are strongly related to small variations in the microstructure, ranging from a fully amorphous phase to nanocrystalline phases with different crystal size. The high thermal stability of bulk metallic glasses makes possible the compression and shaping processes in the temperature range between glass transition and crystallisation. Aim of this paper is to present recent results on glass formation and properties of bulk metallic glasses with various compositions. Examples will be reported on Zr, Fe, Mg and Pd-based materials, focussing on mechanical and magnetic properties.

Effect of Cooling Rate, Tungsten Fiber Addition and Annealing on Deformation and Mechanical Properties of Zr-Based Bulk Metallic Glasses Under a Nanoindenter

2015 ◽  
Vol 1120-1121 ◽  
pp. 68-72
Author(s):  
Yi Si
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Cooling Rate ◽  
Metallic Glasses ◽  
Shear Bands ◽  
Bulk Metallic Glasses ◽  
Tungsten Fiber ◽  
Nanoindentation Instrument ◽  
Scanning Electron ◽  
Fiber Addition

The deformation and mechanical properties of Zr-based bulk metallic glasses (BMGs) under a nanoindenter and the effect of cooling rate, the effect of cooling rate, tungsten fiber addition and annealing on them have been studied by means of a nanoindentation instrument and a scanning electron microscope (SEM). The results indicate that the deformation of Zr-based BMGs under a nanoindenter is characterized by multiple shear bands and viscous flow which confirms the existence of a amount of plastic deformation. For pure quenched Zr-based BMGs, the larger the size of samples or the nearer the location away from the surface of a same sample, the smaller the values of microhardness (Hv) and elastic modulus (E); Annealing and tungsten fiber addition enhance the values of Hv and E; meanwhile, they also significantly change morphology around a nanoindenter and the amount of plastic deformation. The mechanism of plastic deformation is preliminarily analyzed.

Effect of pre-existing shear bands on mechanical properties and serration behaviors in bulk metallic glasses

2017 ◽  
Vol 24 (4) ◽  
pp. 402-410 ◽  
Author(s):  
Xu-dong Yuan ◽  
Sheng-hai Wang ◽  
Kai-kai Song ◽  
Xiao-liang Han ◽  
Yu-sheng Qin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metallic Glasses ◽  
Shear Bands ◽  
Bulk Metallic Glasses

Synthesis of Ni-based bulk metallic glass matrix composites containing ductile brass phase by warm extrusion of gas atomized powders

2003 ◽  
Vol 18 (9) ◽  
pp. 2101-2108 ◽  
Author(s):  
M. H. Lee ◽  
D. H. Bae ◽  
D. H. Kim ◽  
D. J. Sordelet
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Glass Matrix ◽  
Volume Fraction ◽  
Shear Bands ◽  
Second Phase ◽  
Matrix Composites ◽  
Ductile Phase ◽  
Glass Matrix Composites ◽  
Warm Extrusion

To prevent catastrophic failure by propagating highly localized shear bands and to overcome the limited dimension of metallic glass, centimeter-scale Ni59Zr20Ti16Si2Sn3 bulk metallic glass matrix composites were fabricated by warm extrusion of a mixture of gas-atomized fully amorphous powders and ductile brass powders. After consolidation, the composite retained the fully amorphous matrix found in the gas-atomized powder combined with the brass second phase. The glass-transition and crystallization temperatures of the extruded material were the same as those of the starting powders. The confined ductile brass phase enabled the bulk metallic glass matrix composites to deform plastically under uniaxial compression at room temperature. The combination of strength and ductility in the inherently brittle Ni-based monolithic materials could be obtained by introducing a ductile phase in the bulk metallic glass matrix. However, control of the volume fraction and distribution of the ductile brass phase was important for the proper combination of the strength and plasticity.

scholarly journals Formation and Mechanical Properties of Pd-Si Binary Bulk Metallic Glasses

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Na Chen ◽  
Hongxia Zhang ◽  
Ke-Fu Yao
Keyword(s):  
Mechanical Properties ◽  
Metallic Glasses ◽  
Shear Bands ◽  
Bulk Metallic Glasses ◽  
High Strength ◽  
Side Surface ◽  
Alloy System ◽  
Structural Inhomogeneity ◽  
Micrometer Scale ◽  
Scale Shear

Glassy spherical samples in the diameters up to 10 mm were produced in a binary Pd-Si alloy system. These Pd-Si bulk metallic glasses (BMGs) combine high strength of about 1600 MPa and superplasticity of over 70% together. In addition to abundant micrometer-scale shear bands, 10–20 nanometer-sized shear bands were also observed on the side surface of the deformed sample. The excellent ductility shown by the Pd-Si BMGs is suggested to arise from the nanoscale structural inhomogeneity.

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