Description
This thesis involves investigations into powder metallurgical and powder processing techniques for producing single matrix nanocomposites and studying their properties. Carbon Nanotubes (CNTs) have gained a great deal of attention over the past couple of decades for their outstanding properties. These properties have accelerated material scientists to pursue research into new era of preparing CNT reinforced composites. Currently, CNTs are being widely used as reinforcements in metals and ceramics. In this thesis a novel technique called "Spark Plasma Extrusion" was used to fabricate extrudates of CNT-Al single matrix composites in addition to extrudates of milled aluminum. SPEX milling was used to control the CNT dispersion in aluminum powder, in addition to the CNT-aluminum composite powder size and morphology prior to subsequent consolidation. The effect of milling time on the particle size, and shape evolution was investigated in addition to the nano-matrix crystal size. In addition, spark plasma sintering (SPS) was also used to sinter CNT-Al single matrix composites. Characterization of the powder samples, extrudates and sintered samples of CNT-Al composites have also been carried out. The "Spark Plasma Extrusion of CNT-Al single Matrix composite exhibited properties superior to those composites produced using spark plasma sintering. This is largely due to a better consolidated product with refined microstructure.
