Mechanical and microstructural characterization of Cu/CNT nanocomposite layers fabricated via friction stir processing

Abstract

In this study, the effect of incorporation of carbon nanotubes into pure copper was investigated through friction stir processing (FSP). To this end, FSP has been performed using one and three passes. Moreover, the changes in peak temperature of one-pass friction stir processing performed by tools with different shoulder diameters have been recorded. It was found that for the tool with smaller shoulder, the process temperature peak has been significantly reduced. Remarkable reduction in grain size of Cu/carbon-nanotube nanocomposites was observed as compared with the pure copper. Raman spectroscopy results proved a higher extent of degradation of carbon nanotubes upon increasing the friction stir processing passes. On the other hand, microhardness and wear results showed that as the carbon nanotubes are introduced to the pure copper, hardness of composites processed via one-and three-friction stir processing passes showed enhancements of 65 and 105 %, respectively, and the weight losses were also decreased 31 and 68 %, respectively. It was also observed that friction coefficient of one-pass processed composite is lower than that of the pure copper due to the presence of carbon nanotube clusters. Whereas, the friction coefficient of three-pass processed composite was increased regarding to the pure copper. The reduction in slope of wear weight loss upon increasing the applied force at the wear test signified the higher efficiency of the processed composites under harsh conditions.

Assessment of tool wear and mechanical properties of Al 7075 nanocomposite in friction stir processing (FSP)

“…Input parameters including rotation speed, traverse speed and pass number were adjusted in five levels in order to investigate the effect of friction stir processing on tool wear, microhardness, EDS analysis and topography of metal matrix composite aluminum base. The range of input parameters has been selected according to screening tests, literature and previous studies [29][30][31][32]. The total number of experimental tests was 7.…”

Surface integrity of metal matrix nanocomposite produced by friction stir processing (FSP)

“…Main parameters, including rotational speed, pass number, and traverse speed, were set in five levels in order to investigate Al-SiC nanocomposite produced by friction stir processing. The parameters range has been chosen according to the literature, screening tests, and previous researches [19][20][21][22]. The central point was considered with three tests.…”

Effect of Plunge depth on Mechanical properties of Friction Sir welded copper joints

“…This was attributed due to dynamic recrystallization and grain refinement [20][21]. Process parameters and tool parameters are important for generation of heat during friction stir welding [22][23]. For generating the appropriate heat generation suitable process parameters have to select in order to get sound welded joint with enhanced mechanical properties.…”