Investigation of mechanical and electrical properties of multi̇-walled carbon nanotube reinforced copper matrix nanolamine composite

In this study, the mechanical and electrical properties of carbon nanotube reinforced copper matrix composite materials were investigated. Powder metallurgy method was used in the production of composite materials. Multi-walled carbon nanotube particles of 0%, 0.5%, 1%and 1.5%by weight were added into the copper matrix powders Before mixing, the surfaces of the carbon nanotubes were cleaned and activated by applying acid. Subsequently, copper and carbon nanotubes were placed in a ball mixer with a ball/powder ratio of 10:1 and mixed for 120 minutes at a mixing speed of 400 rpm. Mixed powders were compressed unidirectionally in a steel mold at 500, 600 and 700 MPa pressures. The samples produced after compression were subjected to sintering process in argon atmosphere at temperatures of 850°C and 920°C. Microstructure analysis, XRD analysis, hardness measurement and electrical conductivity measurement were performed to determine the effects of production parameters on the physical and mechanical properties of the samples. According to the results, carbon nano tube particles were spread as agglomerate in the structure and this affected the properties of the produced composites. With the increasing carbon nanotube, porosity and agglomeration in the microstructure became evident. As a result, a reduction in relative density of up to 90.47% occurred. There was no significant difference in XRD peaks depending on pressing pressure and sintering temperature, but not for the carbon nanotube. In addition, the electrical conductivity of the composites decreased with increasing content. Depending on the increase in the applied load in the hardness measurements, the samples exhibited a behavior in the form of a trace size effect. In addition, the electrical conductivity of the composites decreased with the increasing amount of carbon nanotubes. The highest electrical conductivity was determined as 76.06 IACS (0%CNT-500 MPa- 920oC) and the lowest electrical conductivity was 39.64 IACS (1.5%CNT-500 MPa- 850oC). KEYWORDS: Composite copper, CNT, powder metallurgy, electrical conductivity