| Summary: | 碩士 === 國立海洋大學 === 材料工程研究所 === 84 === Since copper and carbon are immiscible, Cu-C pseudoalloy is
likely to be a noble material for the high-temperature
applications. In this study, Cu-C pseudoalloys were prepared by
mechanical alloying (MA) and R.F. magnetron sputter deposition
techniques. With careful control of processing conditions, the
carbon concentrations in Cu-C alloys obtained were up to 59.4
and 16.3 at.% by MA and sputter deposition, respectively.
Lattice expansion of Cu evidenced by XRD indicated that
interstitial carbon atoms were in solid solution with copper.
After annealing, a massive phase separation occurred (heated to
400。) for as-milled Cu-C powder, while the precipitation of
carbon-rich nanocrystalline phase appeared in Cu-C films (heated
to 550。). Thermal analysis results showing exothermic
transitions in both cases confirmed the in situ hot stage TEM
observations. Ultra-microhardness results showed hardnesses
increased with carbon contents for both Cu-C powders and films.
Electrical resistivity measurement revealed the resistivities of
Cu-C films decreased with carbon contents for the low carbon
concentrations (<11.3%C) whereas it showed a different trend
above 11.3%C, suggesting the improvement of film microstructure.
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