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

Authors :
Lisa-Marie Weniger
Christoph Gammer
Marek Niewczas
Megan J. Cordill
Florian Spieckermann
Philippe Djemia
Damien Faurie
Chen-Hui Li
Alice Lassnig
Velislava L. Terziyska
Christian Mitterer
Jürgen Eckert
Oleksandr Glushko
Source :
Materials & Design, Vol 232, Iss , Pp 112099- (2023)
Publication Year :
2023
Publisher :
Elsevier, 2023.

Abstract

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.

Details

Language :
English
ISSN :
02641275
Volume :
232
Issue :
112099-
Database :
Directory of Open Access Journals
Journal :
Materials & Design
Publication Type :
Academic Journal
Accession number :
edsdoj.06e3e5e34834dcdbe64c25b2a13717d
Document Type :
article
Full Text :
https://doi.org/10.1016/j.matdes.2023.112099