Mechanical and Tribological Properties of Al2O3-TiC Composite Fabricated by Spark Plasma Sintering Process with Metallic (Ni, Nb) Binders

Abstract

Al2O3-10TiC composites were fabricated through the powder metallurgical process (mechanical milling combined with spark plasma sintering) with the addition of Ni/Nb as metallic binders. The effect of binder addition (Ni/Nb) on the processing, microstructure, and mechanical and tribological properties of the bulk-sintered composite samples was investigated. The microstructure of the composite reveals a homogeneous distribution of the TiC particles in the Al2O3 matrix. However, the presence of Ni/Nb was not traceable, owing to the small amounts of Ni/Nb addition. Hardness and density of the composite samples increase with the increasing addition of Nb (up to 2 wt. % Nb). Any further increase in the Nb content (3 wt. %) decreases both the hardness and the wear resistance. However, in case of Ni as binder, both the hardness and wear resistance increases with the increase in the Ni content from 1 wt. % to 3 wt. %. However, the composite samples with Nb as binder show improved hardness and wear resistance compared to the composites with Ni as binder.