Effect of Alumina Nanofibers Content on the Microstructure and Properties of ATZ Composites Fabricated by Spark Plasma Sintering

Abstract

Abstract In this work, 3\xa0mol.% yttria-stabilized zirconia was used as a matrix for the fabrication of alumina toughened zirconia (ATZ) composites. Alumina nanofibers were reinforcing additives with an amount of 1, 5 and 10\xa0wt.%. Fully dense ATZ composites were obtained by spark plasma sintering. Microstructure observations of the composites showed the mixed fracture mode, which favorably affects the fracture toughness. It is shown that the fracture toughness and Vickers microhardness of ATZ composites were significantly improved by the addition of Al2O3 nanofibers compared with monolithic ZrO2. The fracture toughness of composite with 1\xa0wt.% nanofibers addition is 4.40\xa0MPa·m1/2. The microhardness of composite with 5\xa0wt.% nanofibers is 16.75\xa0GPa. The toughening and strengthening mechanisms were analyzed.