Microstructure and mechanical properties of metastable solid solution copper-tungsten films

THIN SOLID FILMS

卷:642

Article

Thomas, K.¹  Taylor, A. A.^1,2  Raghavan, R.^1,2  Chawla, V.^1,3  Spolenak, R.⁴  Michler, J.¹ 

[1] Empa, Swiss Fed Labs Mat Sci & Technol, Lab Mech Mat & Nanostruct, Feuerwerkerstr 39, CH-3602 Thun, Switzerland

[2] Univ Calif Santa Barbara, Mat Dept, Santa Barbara, CA 93106 USA

[3] CSIR, Sect 30-C, Chandigarh 160030, India

[4] ETH, Lab Nanomet, Dept Mat, Vladimir Prelog Weg 5, CH-8093 Zurich, Switzerland

关键词: Metastable phases;    Nanocrystalline nanostructure;    Nanoindentation;    X-ray diffraction;    Copper;    Tungsten;    Sputtering;   

DOI  :  10.1016/j.tsf.2017.09.007

来源: Elsevier

【 摘 要 】

A combinatorial science approach is utilized to study the microstructural and mechanical properties of metastable copper-tungsten solid solutions. Lateral compositional gradient (also called composition-spread) samples were deposited by simultaneously sputtering copper and tungsten targets positioned obliquely at opposite ends of a silicon substrate. The chemical composition of the film varies continuously along its length from 12 to 45 atomic % copper and has a nominal thickness of 1 mu m. Nanoindentation was performed to measure the hardness and elastic modulus of the film. Grain size and solid solution strengthening models are applied to interpret the hardness of the film, though a simple rule of mixtures is found to give a more satisfactory fit to the data. The elastic modulus of the film is consistently below that predicted by the rule of mixtures. X-ray diffraction revealed plane spacing less than that predicted by Vegard's law as well as three chemical compositions exhibiting enhanced long-range order. Transmission electron microscopy analysis confirms that the film consists of a single metastable body centred cubic solid solution where the lattice spacing and grain size depend on chemical composition.

【 授权许可】

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