Internal structural evolution and enhanced tensile plasticity of Ti-based bulk metallic glass and composite via cold rolling

The structural evolution of the Ti40Zr10Cu34Pd14Sn2 bulk metallic glass (BMG) upon was investigated by means of in situ high-energy x-ray diffraction. The position, width, and intensity of the first peak in diffraction patterns are fitted through Voigt function below 800 K. All the peak position, width, and intensity values show a nearly linear increase with the increasing temperature to the onset temperature of structural relaxation, Tr = 510 K. However, these values start to deviate from the linear behavior between Tr and Tg (the glass transition temperature). The changes in free volume and the coefficient of volume thermal expansion prove that the aforementioned phenomenon is closely related to the structural relaxation releasing excess free volume arrested during rapid quenching of the BMG. Above 800 K, three crystallization events are detected and the first exothermic event is due to the formation of metastable nanocrystals.

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Structural evolution and property changes in Nd60Al10Fe20Co10 bulk metallic glass during crystallization

Applied Physics Letters ◽

10.1063/1.1525053 ◽

2002 ◽

Vol 81 (23) ◽

pp. 4371-4373 ◽

Cited By ~ 39

Author(s):

Zhi Zhang ◽

Lei Xia ◽

Ru Ju Wang ◽

Bing Chen Wei ◽

Ming Xiang Pan ◽

...

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Structural Evolution ◽

Property Changes

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Mechanism of shear banding during cold rolling of a bulk metallic glass

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2018.09.302 ◽

2019 ◽

Vol 773 ◽

pp. 883-889 ◽

Cited By ~ 4

Author(s):

Sergio Scudino

Keyword(s):

Metallic Glass ◽

Cold Rolling ◽

Bulk Metallic Glass ◽

Shear Banding

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Effect of Cold Rolling on the Evolution of Shear Bands and Nanoindentation Hardness in Zr41.2Ti13.8Cu12.5Ni10Be22.5 Bulk Metallic Glass

Nanomaterials ◽

10.3390/nano11071670 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1670

Author(s):

Abhilash Gunti ◽

Parijat Pallab Jana ◽

Min-Ha Lee ◽

Jayanta Das

Keyword(s):

Shear Band ◽

Metallic Glass ◽

Cold Rolling ◽

Bulk Metallic Glass ◽

Shear Bands ◽

Three Dimensional ◽

Peak Loads ◽

Nanoindentation Hardness ◽

Band Spacing ◽

Calorimetric Studies

The effect of cold rolling on the evolution of hardness (H) and Young’s modulus (E) on the rolling-width (RW), normal-rolling (NR), and normal-width (NW) planes in Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vitreloy 1) bulk metallic glass (BMG) was investigated systematically using nanoindentation at peak loads in the range of 50 mN–500 mN. The hardness at specimen surface varied with cold rolling percentage (%) and the variation is similar on RW and NR planes at all the different peak loads, whereas the same is insignificant for the core region of the specimen on the NW plane. Three-dimensional (3D) optical surface profilometry studies on the NR plane suggest that the shear band spacing decreases and shear band offset height increases with the increase of cold rolling extent. Meanwhile, the number of the pop-in events during loading for all the planes reduces with the increase of cold rolling extent pointing to more homogeneous deformation upon rolling. Calorimetric studies were performed to correlate the net free volume content and hardness in the differently cold rolled specimens.

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Effect of Residual Stress on Mechanical Property of Monolithic Bulk Metallic Glass

Materials Science Forum ◽

10.4028/www.scientific.net/msf.654-656.1050 ◽

2010 ◽

Vol 654-656 ◽

pp. 1050-1053

Author(s):

Min Ha Lee ◽

Joong Hwan Jun ◽

Jürgen Eckert

Keyword(s):

Mechanical Properties ◽

Residual Stress ◽

Metallic Glass ◽

Cold Rolling ◽

Bulk Metallic Glass ◽

Metallic Glasses ◽

Metallic Materials ◽

Cyclic Compression ◽

Stress States ◽

Intrinsic Plasticity

Mechanical treatments such as deep rolling are known to affect the strength and toughness of metallic glass due to the residual stress. It is well known that compressive residual stress states usually enhance the mechanical properties in conventional metallic materials. We present investigations on the change of fracture behavior related with mechanical properties of “brittle” bulk metallic glass by cold rolling at room temperature. Improvement of the intrinsic plasticity is observed not only after constrained cyclic compression but also after cold rolling. Moreover, neither nanocrystallization nor phase separation occurs during deformation. By these findings we provide a unique fundamental basis by considering the introduction of structural inhomogeneity and ductility improvement in metallic glasses. The experimental evidence clearly supports that such an inhomogeneous glassy can be produced by residual stress in well known “brittle” bulk metallic glasses, and does not depend on a specific pinpointed chemical composition.

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