Microstructural and Electrical Properties of Copper–Titanium Alloy Dispersed with Carbon Nanotubes via Powder Metallurgy Process
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Microstructural and electrical properties of powder metallurgy (P/M) copper alloy with carbon nanotubes (CNTs) were investigated. The Cu–0.5 mass% Ti pre-alloyed powder (Cu–0.5Ti) was made by water atomization process. The powders coated with un-bundled CNTs by using the zwitterionic surfactant water solution containing CNTs were consolidated at 1223 K in vacuum by spark plasma sintering, and then extruded at 1073 K. The P/M Cu–0.5Ti alloy without CNTs (monolithic alloy) had 202 MPa yield stress (<i>YS</i>) and 42.5 International-Annealed-Copper-Standard % (IACS%) conductivity. The extruded Cu–0.5Ti composite alloy containing CNTs revealed small decrease of <i>YS</i> compared to the monolithic Cu–0.5Ti alloy. On the other hand, the composites indicated a higher electrical conductivity than that of the monolithic alloy. For example, Cu–0.5Ti with 0.19 mass% CNTs showed 175.8 MPa <i>YS</i> and 83.5 IACS% conductivity. In the case of the Cu–0.5Ti composite with CNTs, the intermetallic compounds such as Cu<sub>4</sub>Ti and TiC were observed around CNTs by TEM-EDS analysis. The amount of the solid solute Ti in the above Cu–0.5Ti composite alloy matrix was 10% of the monolithic Cu–0.5Ti alloy, and resulted in the remarkable increment of its electrical conductivity due to the decrease of solid solute Ti content.
- MATERIALS TRANSACTIONS
MATERIALS TRANSACTIONS 55(3), 522-527, 2014
The Japan Institute of Metals and Materials