Precious metal amorphous AgAuSi: Alloy design by swapping gold for silver

Lisa-Marie Weniger, Christoph Gammer, Marek Niewczas, Megan J. Cordill, Florian Spieckermann, Philippe Djemia, Damien Faurie, Chen-Hui Li, Alice Lassnig, Velislava Terziyska, Christian Mitterer, Jürgen Eckert, Oleksandr Glushko

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung


To expand the basis for property-oriented material design, complex relationships between chemistry, atomistic structure, and properties of sputter-deposited AgxAu85-xSi15 alloys are investigated using versatile experimental methods. According to differential scanning calorimetry and X-ray diffraction data, the alloys are amorphous within a wide compositional range of 20 ≤ x ≤ 60 at%. However, high-resolution transmission electron microscopy revealed noticeable amounts of crystallites in limiting compositions with x = 20 at% and x = 60 at%. Glass transition and crystallization temperatures grow with increasing Ag content, while room-temperature resistivity and temperature coefficient of resistance are shown to be highly sensitive to the amount of crystalline phase. Neither the existence of nanocrystallites nor the substitution of Ag by Au affected significantly the mechanical properties. All compositions exhibit similar nanoindentation hardness of about 4.3 GPa, Young’s modulus of about 55 GPa, and macroscopic elastic limit of about 2%. The unique combination of high hardness, high elastic strain but low Young’s modulus together with the expected chemical inertness inherited from noble metals makes this alloy family suitable for biomedical applications in form of coatings or in jewelry if an economic bulk production route will be developed.
FachzeitschriftMaterials and Design
Frühes Online-Datum17 Juni 2023
PublikationsstatusVeröffentlicht - 17 Juni 2023

Bibliographische Notiz

Funding Information:
O.G. would like to acknowledge the support by the Austrian Science Fund (FWF) and Land Steiermark through the project P31544-NBL.

Publisher Copyright:
© 2023 The Author(s)

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