Origin of the Simultaneous Improvement of Strength and Plasticity in Ti-based Bulk Metallic Glass Matrix Composites

W-rich particle-reinforced Ti-based bulk metallic glass (BMG) matrix composites with a compressive strength approaching 3 GPa and a fracture strain of approximately 12% were developed. In contrast to most existing BMG matrix composites, in which the improved ductility was obtained only at the expense of the strength, the composites developed in this study exhibited a significant enhancement in their strength, as well as an improvement in the plasticity. This improvement in the plasticity was attributed to the blocking and circumscription of the shear band propagation, leading to the formation of a large number of shear bands. Using a classical elasticity theory of inclusions, the improvement of the strength was interpreted as resulting from the generation of tensile residual stresses in the matrix due to the difference in the coefficient of thermal expansion between the W-rich particles and the BMG matrix.

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An Analytical Method for Studying the Stress-Strain Relations of Bulk Metallic Glass Matrix Composites under Tension

Advanced Composites Letters ◽

10.1177/096369351802700603 ◽

2018 ◽

Vol 27 (6) ◽

pp. 096369351802700

Author(s):

Yunpeng Jiang

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Analytical Method ◽

Glass Matrix ◽

Shear Bands ◽

Matrix Composites ◽

Stress Strain ◽

Glass Matrix Composites ◽

Softening Stage

In this contribution, an analytical model was formulated to predict the tensile stress-strain relations of bulk metallic glass matrix composites (BMGCs) based on Weng's theoretical frame for dual-ductile composites. For in-situ BMGCs, BMG matrix also exhibits the elastic-plastic deform response as well as the dendrite phases during the stretching. The shear bands are regarded as Mode-I cracks, and whereby the strain-softening stage in the stress-strain curves can be well reflected. Furthermore, multi-particle representative volume element based FEM modelling was employed to clearly explain the failure mechanisms in BMGCs as a necessary complement. The predictions are in reasonable agreement with the experimental results. The presented analytical method will shed some light on optimizing the microstructures, and is of convenience in the engineering applications.

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Synthesis and Properties of Bulk Metallic Glass Matrix Composites

MRS Proceedings ◽

10.1557/proc-554-393 ◽

1998 ◽

Vol 554 ◽

Cited By ~ 6

Author(s):

Haein Choi-Yim ◽

Ralf Busch ◽

William L. Johnson

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Glass Matrix ◽

Compressive Strain ◽

Matrix Composites ◽

X Ray Diffraction ◽

Glass Forming ◽

The Matrix ◽

Glass Matrix Composites ◽

Thermal Stability Of

AbstractBulk metallic glass matrix composites are processed and investigated by X-ray diffraction, DSC, optical microscopy, SEM, microprobe, TEM, and mechanical testing. Ceramics such as SiC, WC, or TiC, and the metals W or Ta are introduced as reinforcements into the metallic melt. The metallic glass matrix remains amorphous after adding up to 30 vol% of particles. The thermal stability of the matrix does not deteriorate after adding the particles. ZrC layers form at the interfaces between the bulk metallic glasses and the WC or SiC particles. Si and W are released into the matrix in which Si enhanced the glass forming ability. The composites are tested in compression and tension experiments. Compressive strain to failure increases by over 300% compared to the unreinforced Zr57Nb5Al10Cu15.4Ni12.6 and the energy to break of the tensile samples increases by over 50% adding 15 vol. % W.

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Internal Stresses in Bulk Metallic Glass Matrix Composites

MRS Proceedings ◽

10.1557/proc-644-l9.3 ◽

2000 ◽

Vol 644 ◽

Cited By ~ 1

Author(s):

Ersan Üstündag ◽

Danut Dragoi ◽

Bjorn Clausen ◽

Donald Brown ◽

Mark A. M. Bourke ◽

...

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Internal Stresses ◽

Matrix Composites ◽

X Ray Diffraction ◽

The Matrix ◽

Superior Mechanical Properties ◽

Two Phases ◽

Glass Matrix Composites ◽

Metallic Fibers

AbstractComposites consisting of a bulk metallic glass (BMG) matrix and metallic fibers or particulates have been shown to exhibit superior mechanical properties as compared to monolithic BMGs. To understand the role of reinforcements in this improvement, it is necessary to investigate the state of internal stresses in these composites. These stresses arise from the thermal expansion mismatch between the reinforcement and the matrix, as well as the elastic and plastic incompatibilities between the two phases. Neutron diffraction and synchrotron X-ray diffraction were used to measure these mismatch-induced stresses in BMG-matrix composites with various reinforcements: continuous W fibers, W or Ta particles, and dendritic, in-situ formed precipitates. The results are compared to numerical and analytical predictions of internal stresses.

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

Journal of Materials Research ◽

10.1557/jmr.2003.0295 ◽

2003 ◽

Vol 18 (9) ◽

pp. 2101-2108 ◽

Cited By ~ 48

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.

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Nanocrystallization at shear bands in bulk metallic glass matrix composites

Scripta Materialia ◽

10.1016/j.scriptamat.2007.11.032 ◽

2008 ◽

Vol 58 (8) ◽

pp. 651-654 ◽

Cited By ~ 16

Author(s):

Min Ha Lee ◽

Dong Hyun Bae ◽

Do Hyang Kim ◽

Won Tae Kim ◽

Daniel J. Sordelet ◽

...

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Glass Matrix ◽

Shear Bands ◽

Matrix Composites ◽

Glass Matrix Composites

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Quasi-static and dynamic deformation behaviors of in situ Zr-based bulk-metallic-glass-matrix composites

Journal of Materials Research ◽

10.1557/jmr.2010.0289 ◽

2010 ◽

Vol 25 (12) ◽

pp. 2264-2270 ◽

Cited By ~ 23

Author(s):

J.W. Qiao ◽

P. Feng ◽

Y. Zhang ◽

Q.M. Zhang ◽

P.K. Liaw ◽

...

Keyword(s):

Mechanical Properties ◽

Metallic Glass ◽

Bulk Metallic Glass ◽

Glass Matrix ◽

Dynamic Deformation ◽

Shear Bands ◽

Matrix Composites ◽

Deformation Behaviors ◽

Glass Matrix Composites

Quasi-static and dynamic deformation behaviors of Zr-based bulk-metallic-glass-matrix composites, fabricated by Bridgman solidification, were investigated in this study. Upon quasi-static compressive loading, the composites exhibit ultrahigh strength, accompanied by considerable plasticity. The multiplication of shear bands on the lateral surface of deformed samples, and the highly-dense liquid drops on the fracture surface, are in agreement with the improved plasticity. However, upon dynamic loading, the mechanical properties of the composites deteriorate considerably, due to insufficient time to form profuse shear bands. The strain-rate responses of the mechanical properties of the crystalline alloys and the in situ and ex situ bulk metallic glass composites are compared, and the different deformation mechanisms of the in situ composites upon quasi-static and dynamic loading are explained.

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