In this study, Mg-Cu thin film metallic thin films were fabricated via two ways, the co-deposition and post-annealing of the multilayered thin films. Amorphous Mg1-xCux, where x is from 38 to 82, thin films with nanocrystalline particles are able to be fabricated via co-sputtering. The mechanism of formation is different from the rapid quenching process.
For the Mg-Cu co-sputtering system, the mechanical properties of the Mg-Cu co-sputtered films were tested via MTS nanoindenter. Mg23.5Cu76.5 exhibits a higher Young¡¦s modulus than Mg17.7Cu82.3 and Mg40.4Cu59.6 due to the partial amorphous structure. Moreover, the pop-in effects with a smaller size occurs of the Mg23.5Cu76.5 sample in a higher frequency than of the Mg17.7Cu82.3 and Mg40.4Cu59.6 samples. The small pop-in effects in the Mg23.5Cu76.5 sample approximate match the width of amorphous matrix via the HRTEM observation.
Another process to form the amorphous thin film is via the post isothermal annealing process of the multilayered thin films. However, for the specimens of 20T32 consisting of 150-nm Mg and 50-nm Cu individual layers, the Mg individual layers would react to the Cu individual layers during the annealing at a temperature of 413 K owning to the slight negative heat of mixing. Due to the localized diffusion near the interfaces, Mg2Cu gradually form during the isothermal annealing since Mg2Cu is the most stable phase below 548 K [62]. Localized interdiffusion near the interfaces between Mg and Cu individual layers induced the formation of Mg2Cu rapidly. For the 40T32 specimens consisting of 15 nm Mg and 5 nm Cu individual layers, Mg2Cu rapidly form at 413 K due to the high interface energy. Then, the similar result exhibits in the 20T14 and 40T14 specimens annealed at 363 K.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0710107-193739 |
| Date | 10 July 2007 |
| Creators | Chou, Hung-Sheng |
| Contributors | Chu, Jinn P, Liuwen Chang, Huang, J. Chih-Ching |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0710107-193739 |
| Rights | withheld, Copyright information available at source archive |
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