Viscous Flow Behaviour of Supercooled Liquids and Mechanical Properties in Zr-Cu-Ni-Al Bulk Metallic Glasses

Viscous flow behaviour of supercooled liquids and mechanical properties in Zr55+XCu30-XNi5Al10 (X=0, 5 and 10 at. %) and Zr65Cu18Ni7Al10 bulk metallic glasses (BMGs) have been examined. Viscosity has been measured by using a penetration viscometer at a high-speed heating rate of 400 K/min. With increasing Zr-content, Tg tended to decrease and Tx tended to increase, resulting Tx (=Tx-Tg) increaseing up to about 170 K under a heating rate of 400 K/min by the DSC analysis. The viscosity lowered about one order of magnitude, e.g., minimum value of the viscosity decreased from 3~4x106 Pa-s for the Zr55Cu30Ni5Al10 and Zr60Cu25Ni5Al10 BMGs down to 5~6x105 Pa-s for the Zr65Cu20Ni5Al10 and Zr65Cu18Ni7Al10 BMGs under the same heating condition. Compression tests were also carried out at a slow strain rate of about 1 x 10-4 s-1 at room temperature. With increasing Zr-content, the apparent yield stress was decreased but the total strain at fracture was increased significantly, suggesting that there is a strong relationship between viscosity and the mechanical properties in these BMGs.

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Viscous Flow Behaviors of Supercooled Liquids of Pre-Annealed Zr55Cu30Al10Ni5 Bulk Metallic Glasses

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.1271 ◽

2007 ◽

Vol 561-565 ◽

pp. 1271-1274 ◽

Cited By ~ 2

Author(s):

Tohru Yamasaki ◽

S. Maeda ◽

Takeyuki Kikuchi ◽

Takeshi Fukami ◽

Yokoyama Yoshihiko ◽

...

Keyword(s):

Viscous Flow ◽

Metallic Glasses ◽

High Speed ◽

Applied Load ◽

Flow Behavior ◽

Bulk Metallic Glasses ◽

Supercooled Liquid ◽

Supercooled Liquids ◽

Supercooled Liquid Region ◽

Liquid Region

Viscous flow behavior in supercooled liquid region of as-cast and pre-annealed Zr55Cu30Al10Ni5 bulk metallic glasses has been examined by using a penetration viscometer under high-speed heating rate of 20, 200 and 400 °C/min. Applied load for the cylindrical-shaped penetration indenter with a diameter of 1 mm was varied from 0.049 N to 0.294 N. Viscosity was quite independent of these applied loads. By pre-annealing the bulk metallic glasses at 400 °C, the density of the glasses increased, while the viscosity and the activation energy for viscous flow in their soopercooled liquid decreased with the pre-annealing treatments. Corresponding measurements of the differential thermal calorimetry (DSC) have been also done.

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Ductile Zr-Based Bulk Metallic Glasses by Controlling Heterogeneous Microstructure from Phase Competition Strategy

Nanomaterials ◽

10.3390/nano9121728 ◽

2019 ◽

Vol 9 (12) ◽

pp. 1728 ◽

Cited By ~ 1

Author(s):

J. L. Cheng ◽

J. J. Wang ◽

J. X. Rui ◽

Y. L. Yun ◽

W. Zhao ◽

...

Keyword(s):

Mechanical Properties ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

High Strength ◽

Primary Phase ◽

Competition Strategy ◽

Compression Tests ◽

Phase Competition ◽

Superior Mechanical Properties ◽

New Perspective

In this paper, we prepare the alloys of Zr41.2Ti13.8Cu12.5Ni10Be22.5, Zr44.4Ti14.8Cu14.3Ni11.5Be15, and Zr38Ti12.7Cu9.6Ni7.7Be32 to show the effects of alloy composition on the inhomogeneity structures and mechanical properties of Zr-based bulk metallic glasses (BMGs). Compared with the best glass former Zr41.2Ti13.8Cu12.5Ni10Be22.5, some nanoscale inhomogeneity structures can be induced by shifting the compositions towards a primary phase in the alloys of Zr44.4Ti14.8Cu14.3Ni11.5Be15 and Zr38Ti12.7Cu9.6Ni7.7Be32. The room temperature compression tests reveal that theBMGs contained nanoscale inhomogeneity structures exhibit superior mechanical properties with the high strength of 1780 MPa and especially a remarkable plastic strain of over 9%. These findings provide a new perspective to enhance the ductility of BMGs by introducing nanoscale inhomogeneity structures based on the phase competition strategy.

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