Microstructural and temperature-dependent deformation mechanisms governing the cyclic creep of freestanding, submicrometer gold thin films

Krapf A, Wagner T, Schretter L, Gebhart DD, Cordill MJ, Gammer C, Merle B (2025)

Publication Language: English

Publication Type: Journal article

Publication year: 2025

Journal

Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing Elsevier

Book Volume: 942

Article Number: 148686

DOI: 10.1016/j.msea.2025.148686

Abstract

A detailed understanding of the fatigue behavior of freestanding metallic films is crucial for extending the lifetime of microsensors and actuators. Previous investigations have pointed at cyclic creep as the dominant deformation mechanism in columnar gold thin films. Here, we investigate the widespread ultra-fine grained (UFG) and nanocrystalline (NC) microstructures, at typical operational temperatures from ambient to 100 °C. While the UFG films show low failure strains, the NC samples can withstand several percents strain, which was attributed to their high initial dislocation density. The combination of strength and ductility in NC films results in superior fatigue lifetimes compared to the UFG films for both low-cycle and high-cycle fatigue regimes. At the highest temperature, NC films even evidence an unexpected fatigue limit. Cyclic creep was evident for all microstructural conditions and temperatures. Hence, creep and diffusion processes are dominant, especially in the low dislocation density UFG gold films. In addition, NC films experience a reduction of the high-angle grain boundaries after cycling at 23 °C and local grain coarsening at 100 °C.

Authors with CRIS profile

Anna Krapf Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Involved external institutions

Erich Schmid Institute of Materials Science of the Austrian Academy of Sciences AT Austria (AT) Universität Kassel DE Germany (DE)

How to cite

APA:

Krapf, A., Wagner, T., Schretter, L., Gebhart, D.D., Cordill, M.J., Gammer, C., & Merle, B. (2025). Microstructural and temperature-dependent deformation mechanisms governing the cyclic creep of freestanding, submicrometer gold thin films. Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 942. https://doi.org/10.1016/j.msea.2025.148686

MLA:

Krapf, Anna, et al. "Microstructural and temperature-dependent deformation mechanisms governing the cyclic creep of freestanding, submicrometer gold thin films." Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing 942 (2025).

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