Mechanism for Light Emission During Fracture of a Zr-Ti-Cu-Ni-Be Bulk Metallic Glass: Temperature Measurements in Air and Nitrogen

1998 ◽  
Vol 554 ◽  
Author(s):  
C. J. Gilbert ◽  
J. W. Ager ◽  
V. Schroeder ◽  
R. O. Ritchie
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Light Emission ◽  
Emission Spectra ◽  
Broad Peak ◽  
Glass Temperature ◽  
Local Melting ◽  
Fresh Material ◽  
Intense Light ◽  
Pendulum Impact

AbstractLight emitted during rupture of Zr41.2Ti13.8Cu12.5 Ni10Be22.5 (at%) bulk metallic glass has been investigated. Charpy V-notch specimens fractured in a pendulum impact apparatus were used to excite light emission. Spectra acquired from rupture in air exhibited a single broad peak and were fit to a blackbody temperature of ∼3175 K. In nitrogen, however, light emission was no longer visible to the eye. In this case, the captured light was at least four orders of magnitude less intense, and spectra were shifted to the red with an effective blackbody temperature of ∼1400 K. Fracture surfaces generated in both air and nitrogen exhibited local melting, providing further evidence of intense heating during fracture. Based on these observations we argue that the intense light emission in air is associated with pyrolysis of fresh material exposed during rupture. Results were compared to preliminary observations of light emission from ribbons of a Zr57Nb5Ni12.6Cu15.4Al10 (at%) glass.

scholarly journals Soft Ferromagnetic Bulk Metallic Glass with Potential Self-Healing Ability

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1319
Author(s):  
Parthiban Ramasamy ◽  
Mihai Stoica ◽  
Gabriel Ababei ◽  
Nicoleta Lupu ◽  
Jürgen Eckert
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Vital Role ◽  
Self Healing ◽  
Local Melting ◽  
Mold Casting ◽  
Soft Ferromagnetic ◽  
Molten Droplets ◽  
Shear Transformation Zones ◽  
Ferromagnetic Bulk

A new concept of soft ferromagnetic bulk metallic glass (BMG) with self-healing ability is proposed. The specific [Fe36Co36B19.2Si4.8Nb4]100−x(Ga)x (x = 0, 0.5, 1 and1.5) BMGs prepared by copper mold casting were investigated as a function of Ga content. The Ga-containing BMGs still hold soft magnetic properties and exhibit large plastic strain of 1.53% in compression. Local melting during shearing produces molten droplets of several µm size throughout the fracture surface. This concept of local melting during shearing can be utilized to produce BMGs with self-healing ability. The molten regions play a vital role in deflecting shear transformation zones, thereby enhancing the mechanical properties.

Machinability of BMG

2012 ◽  
Vol 521 ◽  
pp. 225-253
Author(s):  
Mustafa Bakkal
Keyword(s):  
High Temperature ◽  
Metallic Glass ◽  
Viscous Flow ◽  
Bulk Metallic Glass ◽  
Light Emission ◽  
Cutting Speed ◽  
Good Surface ◽  
High Cutting Speed ◽  
Exothermic Chemical Reaction ◽  
Good Surface Roughness

This chapter covers the series of machinability evaluation test result and discussions of Zr52.5Ti5Cu17.9Ni14.6Al10bulk metallic glass (BMG). These tests are lathe turning, drilling, milling and preliminary level grinding tests. In the continuous machining methods such as turning, drilling and grinding of BMG, above a threshold cutting speed, the low thermal conductivity of BMG leads to chip temperatures high enough to cause the chip oxidation and associated light emission. The high temperature produced by this exothermic chemical reaction causes crystallization within the chips. Chips morphology suggests that increasing amounts of viscous flow control the chip-removal process. Moreover, viscous flow and crystallization can occur during the machining of the bulk metallic glass, even under the high temperature gradient and strain rate. High cutting speed significantly reduced the forces for BMG machining due to thermal softening. However, in intermittent cutting process which is milling, there is no high temperature problem, special burr formations the rollover and the top burr were observed along the slot and achieved good surface roughness, Ra= 0.113 μm, using conventional WC-Co cutting tool. In each method, tests repeated for the conventional materials for comparison purpose. This study concludes the precision machining of BMG is possible with the selection of feasible tools and process parameters for each method.

Light Emission and Dynamic Failure Mechanism of Hypervelocity Impact on Zr-Ti-Ni-Cu-Be Bulk Metallic Glass

2011 ◽  
Vol 28 (9) ◽  
pp. 096102 ◽  
Author(s):  
Bao-Ru Sun ◽  
Zai-Ji Zhan ◽  
Bo Liang ◽  
Rui-Jun Zhang ◽  
Wen-Kui Wang
Keyword(s):  
Metallic Glass ◽  
Failure Mechanism ◽  
Bulk Metallic Glass ◽  
Light Emission ◽  
Hypervelocity Impact ◽  
Dynamic Failure

Light emission during fracture of a Zr–Ti–Ni–Cu–Be bulk metallic glass

1999 ◽  
Vol 74 (25) ◽  
pp. 3809-3811 ◽  
Author(s):  
C. J. Gilbert ◽  
J. W. Ager ◽  
V. Schroeder ◽  
R. O. Ritchie ◽  
J. P. Lloyd ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Light Emission

scholarly journals Local melting to design strong and plastically deformable bulk metallic glass composites

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Yue-Sheng Qin ◽  
Xiao-Liang Han ◽  
Kai-Kai Song ◽  
Yu-Hao Tian ◽  
Chuan-Xiao Peng ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Local Melting ◽  
Glass Composites ◽  
Bulk Metallic Glass Composites

Machinability of Bulk Metallic Glass Materials on Milling and Drilling

2009 ◽  
Vol 83-86 ◽  
pp. 335-341 ◽  
Author(s):  
Mustafa Bakkal ◽  
Veli Nakşiler ◽  
Bora Derin
Keyword(s):  
Surface Roughness ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Light Emission ◽  
Cutting Tools ◽  
Burr Formation ◽  
Tool Paths ◽  
Good Surface ◽  
Good Surface Roughness ◽  
Exit Burr

In this study, machinability of Zr-based bulk metallic glass (Zr52.5Ti5Cu17.9Ni14.6Al10) (BMG) material was investigated by conducting a set of milling and drilling experiments. In milling, two different tool paths, spiral and slot milling, were used. To investigate the behavior of BMG in drilling by two different tools at different feed rates, two sets of drilling experiments are conducted. Crown shaped exit burr formation are observed in drilling of BMG. Best results on thrust force, exit burr formation and hole surface roughness is obtained while using micrograin WC tool on BMG drilling. No chip light emission was observed during all tests. This study concludes that BMG can be achieved machining with good surface roughness, (Ra=0.113 µm), using conventional cutting tools.

scholarly journals Structural Characteristics and Crystallization of Metallic Glass Sputtered Films by Using Zr System Target

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Katsuyoshi Kondoh ◽  
Kenshi Kawabata ◽  
Tadashi Serikawa ◽  
Hisamichi Kimura
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Structural Characteristics ◽  
The Other ◽  
Broad Peak ◽  
Composite Target ◽  
Sputtered Films ◽  
Radio Frequency Sputtering ◽  
Amorphous Structures ◽  
Glass Target

Zr-Al-Ni-Cu thin films were deposited by the radio-frequency sputtering method at low substrate temperature using three kinds of targets:Zr55Al10Ni5Cu30bulk metallic glass target (α-BMG target), crystallized bulk metallic glass target (c-BMG target), and an elemental composite target composed of each Zr, Al, Ni chips, and Cu plate. XRD profiles of the films prepared when using these targets indicated that all of the films showed amorphous structures. While XRD profiles of the films usingα- and c-BMG targets revealed a broad peak of2θ=38degree in the same way as theα-BMG target indicating amorphous structures, that of the film using elemental composite targets showed a broad peak of2θ=42degree, which is higher compared to the latter material. As a result of annealing the films at various temperatures for 900 seconds, the film using theα-BMG target showed a crystallization temperature of 748 K, higher than that of BMG with 723 K, while the other films had lower crystallization temperatures below 723 K. XRD profiles also indicated that the crystallized compounds of the films were different from those of BMG target.

Light emission, chip morphology, and burr formation in drilling the bulk metallic glass

2005 ◽  
Vol 45 (7-8) ◽  
pp. 741-752 ◽  
Author(s):  
Mustafa Bakkal ◽  
Albert J. Shih ◽  
Samuel B. McSpadden ◽  
C.T. Liu ◽  
Ronald O. Scattergood
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Light Emission ◽  
Chip Morphology ◽  
Burr Formation
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