Aligned carbon nanotubes in ceramic-matrix nanocomposites prepared by high-temperature extrusion

Carbon nanotube (CNT)–metal-oxide nanocomposites are extruded at high temperatures. The superplastic forming is made easier by the CNTs. It is possible to align the CNTs in ceramic-matrix nanocomposites, which are bulk materials rather than fibers or thin films. The CNTs withstand the extreme shear stresses occurring during the extrusion. In addition to electron microscopy revealing the alignment, the materials show an anisotropy of the electrical conductivity, which could be adjusted by controlling the amount of CNTs.