Magnesium Technology 2014 - TMS 2014 143rd Annual Meeting and Exhibition, San Diego, CA, United States Of America, 16 - 20 February 2014, pp.429-433
Carbon nanotube (CNT) reinforced magnesium (Mg) matrix composite rod was successfully fabricated by mechanical ball milling followed by hot extrusion processes. CNTs used were multi-wall carbon nanotubes (MWCNTs). The starting Mg chips were ball-milled under argon atmosphere for 3 h to coat the surface of Mg chips with the pretreated MWCNTs. The CNT-coated Mg chips were then mixed with aluminum (Al) powder at the compositions of Mg-6 wt.% Al-x wt.% CNT (x = 0.5, 1, 2 and 4). The mixture was cold compacted and finally hot extruded. The distribution of CNTs was analyzed using a Scanning Electron Microscopy (SEM). Furthermore, the effect of CNTs and their amounts on the mechanical properties and corrosion behavior of the Mg composite were studied. Microstructural analysis revealed that the CNTs were well dispersed at the chip surfaces and were aligned with direction of the extrusion in the composites. As CNT content increased, chip size, density and electrical conductivity of the Mg composites decreased, a relatively constant value was obtained in the microhardness but a reduction was determined in compressive strength. While an increase up to 2 wt.% in CNT content reduced the corrosion rate of the composites, the corrosion rate increased at higher addition rates.