TY - JOUR

T1 - Precious metal amorphous AgAuSi

T2 - Alloy design by swapping gold for silver

AU - Weniger, Lisa-Marie

AU - Gammer, Christoph

AU - Niewczas, Marek

AU - Cordill, Megan J.

AU - Spieckermann, Florian

AU - Djemia, Philippe

AU - Faurie, Damien

AU - Li, Chen-Hui

AU - Lassnig, Alice

AU - Terziyska, Velislava

AU - Mitterer, Christian

AU - Eckert, Jürgen

AU - Glushko, Oleksandr

N1 - Publisher Copyright: © 2023 The Author(s)

PY - 2023/6/17

Y1 - 2023/6/17

N2 - 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.

AB - 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.

UR - https://pureadmin.unileoben.ac.at/portal/en/publications/precious-metal-amorphous-agausi(81ba56c3-ad07-4f94-ad63-856d3ec910db).html

U2 - 10.1016/j.matdes.2023.112099

DO - 10.1016/j.matdes.2023.112099

M3 - Article

VL - 232.2023

JO - Materials and Design

JF - Materials and Design

SN - 0264-1275

IS - August

M1 - 112099

ER -