Novel Characterizations of Mechanical Properties for a Copper/Single-Walled Carbon Nanotube Nanocomposite Synthesized by Laser Surface Implanting

In our previous studies, we have developed a wet process, denoted laser surface implanting (LSI), to synthesize a copper/single-walled carbon nanotube (Cu–SWCNT) metal nanocomposite as an implant onto the surface of a pure copper substrate. The nanostructure of this Cu–SWCNT composite was confirmed independently by several methods, including transmission electron microscope (TEM) images, which show discernable SWCNT clusters in nano sizes inside the copper matrix. The hardness was measured by micro-hardness tests to indicate over three times hardness over that of pure copper could be achieved. In this paper, we present several unique ways to further characterize the mechanical properties of the Cu-SWCNT nanocomposite. Nano-hardness tests are first performed to confirm that hardness improvement, about three times that of pure copper, is achieved, consistent with the micro-hardness test results. A new toughness measurement based on focus ion beam (FIB) bombardment was performed to demonstrate 2.5 times toughness improvement. Finally, a new compression test rig was designed to conduct plane strain compression test for an array of Cu-SWCNT implants. The results confirmed that the Cu-SWCNT nanocomposite exhibits a stress-strain behavior consistent with the results of the hardness and FIB tests.