Mechanical Properties of PM CNT-Dispersed Cu Composite

Abstract:

Microstructural and mechanical properties of powder metallurgy (PM) with carbon nanotube (CNTs) dispersed copper (Cu) composites were investigated in detail. Pure copper powder was coated with un-bundled CNTs by using the zwitterionic surfactant solution containing CNTs. The powder rolling process was applied to increase the powder surface area to be coated with CNTs. The total rolling reduction of Cu-CNT composite powder by 5 steps rolling was about 75%. With increasing the number of rolling steps, the content of CNTs coated on the Cu powder surface increased because of the increment of the flat surface area of flaky Cu rolled powder. As a result, the CNT content was 0.67mass% after 5 steps powder rolling. It was about twice as that of as-coated Cu-CNT composite powder without rolling. The grain size of PM extruded Cu-CNT composite was about one fifth of that of the extruded monolithic Cu material without CNT. Yield stress of the extruded Cu-CNT composite via the rolling process was 192 MPa, which is about twice that of the extruded monolithic Cu material (88 MPa). CNTs distributed at primary particle boundaries were effective to prevent the grain coarsening by their pinning effects, and this grain refinement was the main strengthening factor of the Cu-CNT composite via rolling process.

• Periodical: Key Engineering Materials (Volume 737)
• Pages: 320-325
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.737.320
• Online since: June 2017
• Authors: Hisashi Imai*, Katsuyoshi Kondoh, Junko Umeda
• Keywords: Carbon Nanotube, Mechanical Properties, Pinning Effect, Powder Rolling, Pure Copper

References

[1] H. Atsumi, et al., High-strength Lead-free Machinable Duplex Phase Brass Cu–40Zn–Cr–Fe–Sn–Bi Alloys, Materials Science and Engineering A, 529 (2011), 275-281.

DOI: 10.1016/j.msea.2011.09.029

[2] S. Li, et al., The Effects of Ti and Sn Alloying Elements on Precipitation Strengthened Cu40Zn Brass Using Powder Metallurgy and Hot Extrusion, Materials Science and Engineering A, 535 (2012), 22-31.

DOI: 10.1016/j.msea.2011.12.036

[3] Y. Sakai and H.J. Chneider Muntau, Ultra-high Strength High Conductivity Cu-Ag Alloy Wires, Acta Matellurgica, 45(3) (1997), 1017-1023.

DOI: 10.1016/s1359-6454(96)00248-0

[4] N. Khandoker et al., Tensile Strength of Spinnable Multiwall Carbon Nanotubes, Procedia Engineering, 10 (2011), 2572-2578.

DOI: 10.1016/j.proeng.2011.04.424

[5] S. Xie et al., Mechanical and Physical Properties on Carbon Nanotube, Journal of Physics and Chemistry of Solids, 61 (2000), 1153-1158.

[6] K. Kondoh et al., Microstructural and Mechanical Analysis of Carbon Nanotube Reinforced Magnesium Alloy Powder Composites, Materials Science and Engineering A, 527 (2010), 4103-4108.

DOI: 10.1016/j.msea.2010.03.049

[7] K. Kondoh et al., Characteristics of Powder Metallurgy Pure Titanium Matrix Composite Reinforced with Multiwall Carbon Nanotubes, Composites Science and Technology, 69 (2009), 1077-1081.

DOI: 10.1016/j.compscitech.2009.01.026

[8] J.H.E. Jeffes: Ellingham Diagrams, Encyclopedia of Materials: Science and Technology (Second Edition), (2001) 2751-2753.

DOI: 10.1016/b0-08-043152-6/00490-3