Microscale Thermoplastic Forming of Bulk Metallic Glasses: Numerical Simulations and Experiments

Volume 13: Nano-Manufacturing Technology; and Micro and Nano Systems, Parts A and B ◽

10.1115/imece2008-67340 ◽

2008 ◽

Author(s):

David L. Henann ◽

Lallit Anand

Keyword(s):

Numerical Simulation ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Processing Parameters ◽

Hot Embossing ◽

Simulation Tool ◽

Processing Conditions ◽

Trial And Error ◽

Physical Experiments ◽

Thermoplastic Forming

An extremely promising microscale processing method for bulk metallic glasses called thermoplastic forming has emerged in recent years. However, most of the recent experimental thermoplastic forming studies have been conducted by trial-and-error. In this paper, the large-deformation constitutive theory of Henann and Anand [1] is used as a numerical simulation tool for the design of micro-hot-embossing processes. This numerical simulation capability is used to determine appropriate processing parameters in order to carry out several successful micron-scale hot-embossing operation on the metallic glass Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vitreloy-1). By carrying out the corresponding physical experiments, it is demonstrated that microscale features in Vitreloy-1 may be accurately replicated under the processing conditions determined by use of the numerical simulation capability.

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Microscale Thermoplastic Forming of Bulk Metallic Glasses: Numerical Simulation and Experiments

MRS Proceedings ◽

10.1557/proc-1048-z04-05 ◽

2007 ◽

Vol 1048 ◽

Author(s):

David Henann ◽

Lallit Anand

Keyword(s):

Numerical Simulation ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Processing Parameters ◽

Hot Embossing ◽

Processing Method ◽

Simulation Tool ◽

Processing Conditions ◽

Trial And Error ◽

Thermoplastic Forming

AbstractAn extremely promising microscale processing method for bulk metallic glasses called thermoplastic forming has emerged in recent years. However, most of the recent experimental thermoplastic forming studies have been conducted by trial-and-error. In this paper, we use the large-deformation constitutive theory of Henann and Anand [1] as a numerical simulation tool for the design of a micro-hot-embossing process. This numerical simulation capability is used to determine appropriate processing parameters in order to carry out a successful micron-scale hot-embossing operation on the metallic glass Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vitreloy-1). By carrying out a corresponding physical experiment, we demonstrate that micron-scale features in Vitreloy-1 may be accurately replicated under the processing conditions determined by use of the numerical simulation capability.

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A Conflict of Fineness and Stability: Platinum- and Palladium-Based Bulk Metallic Glasses for Jewellery

Johnson Matthey Technology Review ◽

10.1595/205651321x16045078967011 ◽

2020 ◽

Author(s):

O. S. Houghton ◽

A. L. Greer

Keyword(s):

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Precious Metals ◽

High Hardness ◽

Scratch Resistance ◽

Cast State ◽

High Definition ◽

Glass Forming ◽

Thermoplastic Forming ◽

Near Net Shape

For the metals used in jewellery, high hardness and the associated scratch resistance are much sought after. Conventional crystalline alloys for jewellery are alloyed and extensively processed (thermally and mechanically) to improve hardness, but it is difficult to reach values beyond 300 HV. The advent of bulk metallic glasses, based on precious metals and with hardness exceeding 300 HV in the as-cast state, is therefore of great interest for both jewellery and watchmaking. The non-crystalline structure of these materials not only gives high hardness, but also the opportunity to shape metals like plastics, via thermoplastic forming. For more traditional jewellery manufacture, bulk metallic glasses also exhibit high-definition and near-net-shape casting. Gold-based alloys have long dominated the consideration of bulk metallic glasses for jewellery as they can comply with 18K hallmarks. Although bulk metallic glasses based on platinum or palladium possess excellent thermoplastic formability, and are without known tarnishing problems, achieving useful glass-forming ability within the more restrictive hallmarking standards typically used for jewellery (≥95 wt.% Pt or Pd) is, at best, challenging. In this review, platinum- and palladium-based bulk metallic glasses are discussed, focusing on their potential application in jewellery and on the further research that is necessary.

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Micro-patterning by thermoplastic forming of Ni-free Ti-based bulk metallic glasses

Materials & Design ◽

10.1016/j.matdes.2017.01.080 ◽

2017 ◽

Vol 120 ◽

pp. 204-211 ◽

Cited By ~ 15

Author(s):

Supriya Bera ◽

Baran Sarac ◽

Sascha Balakin ◽

Parthiban Ramasamy ◽

Mihai Stoica ◽

...

Keyword(s):

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Micro Patterning ◽

Thermoplastic Forming

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Sub-second thermoplastic forming of bulk metallic glasses by ultrasonic beating

Scientific Reports ◽

10.1038/srep17844 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 19

Author(s):

Jiang Ma ◽

Xiong Liang ◽

Xiaoyu Wu ◽

Zhiyuan Liu ◽

Feng Gong

Keyword(s):

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Thermoplastic Forming

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A new CoFe-based bulk metallic glasses with high thermoplastic forming ability

Scripta Materialia ◽

10.1016/j.scriptamat.2013.07.002 ◽

2013 ◽

Vol 69 (7) ◽

pp. 553-556 ◽

Cited By ~ 14

Author(s):

Qikui Man ◽

Akihisa Inoue ◽

Yaqiang Dong ◽

Jian Qiang ◽

Chengliang Zhao ◽

...

Keyword(s):

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Thermoplastic Forming

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Thermoplastic forming of bulk metallic glasses

Acta Physica Sinica ◽

10.7498/aps.66.176404 ◽

2017 ◽

Vol 66 (17) ◽

pp. 176404

Author(s):

Ma Jiang ◽

Yang Can ◽

Gong Feng ◽

Wu Xiao-Yu ◽

Liang Xiong

Keyword(s):

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Thermoplastic Forming

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Residual Stresses in Bulk Metallic Glasses due to Differential Cooling or Thermal Tempering

MRS Proceedings ◽

10.1557/proc-554-431 ◽

1998 ◽

Vol 554 ◽

Cited By ~ 4

Author(s):

E. Ustundag ◽

B. Clausen ◽

J. C. Hanan ◽

M. A. M. Bourke ◽

A. Winholtz ◽

...

Keyword(s):

Residual Stress ◽

Thermal Expansion ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Thermal Gradients ◽

Processing Conditions ◽

Strain Gages ◽

Compressive Stresses ◽

Thermal Tempering ◽

Stress Buildup

AbstractDue to their very low thermal conductivities and large thermal expansion values, bulk metallic glasses (BMGs) undergo differential cooling during processing. Large thermal gradients are generated across a specimen leading to residual stress buildup. A thin surface layer contains compressive stresses balanced by tension in the middle. Such stresses can not only influence the mechanical behavior of BMGs, but they can also lead to problems during manufacturing of large or intricate components. Analytical and finite element modeling was used to predict the values and distribution of such stresses as a function of processing conditions. Neutron diffraction measurements were then performed on model specimens which included crystalline phases as “strain gages”. It was shown that significant stresses, on the order of several hundred MPa, can be generated in BMGs. Modeling and diffraction results are presented and their implications discussed.

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