To evaluate the application of alkoxide sol-gel method in fabrication of 3YSZ-MWCNTs nanocomposites, in an attempt to improve its mechanical properties

Abstract

In the present research work, fabrication of YSZ-CNTs composite system through alkoxide sol-gel processing was evaluated, in an attempt to improve its mechanical properties. Nanocomposites containing 0.5-2 wt% MWCNTs were then fabricated through the hydrolysis and condensation processing of the solution mixtures containing alkoxide and inorganic precursors along with the functionalized CNTs under basic condition and its final sintering by the SPS technique at 1400°C. Results showed the formation of a nanocomposite powder based on pure 3YSZ matrix, with well dispersion of CNTs and its good adhesion to the matrix particles in composite containing 0.5 wt% CNTs. The fracture toughness of sintered samples showed around 24% increase for the composite containing 0.5 wt% CNTs. The fracture toughness, hardness, and density decreased due to the agglomeration of CNTs over 0.5 wt%. Toughening mechanisms including pullout and crack bridging were observed on the polished and fractured surfaces.