In this research, ductile and high-strength Cu-carbon nanotube (Cu-CNT) composites with different volume
fractions of CNTs were fabricated using powder metallurgy route including mechanical milling and
hot pressing and microstructure and tensile properties of the resulting materials were studied.
Microstructural characterization through scanning electron microscope and quantifying the CNT
agglomeration revealed that uniform dispersion of CNTs in Cu matrix decreases with increasing CNT
volume fraction. In case of the higher volume fraction of CNTs (i.e., 8 vol.%), 40% of CNTs were
observed as agglomerates in the microstructure. Compared to unreinforced Cu, the yield and ultimate
tensile strengths increased considerably (about 33% and 12%, respectively) with incorporation of CNTs up
to 4 vol.%, but remained constant afterward. Meanwhile, the elongation decreased from 15.6% for Cu to
6.9% for Cu with 8 vol.% CNT. The relationship between the change in yield strength of the composite and
the microstructure was investigated using analytical models. The results showed good consistency between
calculated and measured data when the negative effect of CNT agglomerates in the models were taken into
account.