Effects of Cr2O3 addition on the mechanical properties, microstructure and wear performance of zirconia-toughened-alumina (ZTA) cutting inserts

The effects of Cr2O3 addition on microstructure, the mechanical properties and wear performance of ZTA were investigated. The powders of alumina, yttria partially stabilized zirconia and chromia were mixed and uniaxially pressed into rhombic cutting tool inserts and subsequently sintered at 1600 degrees C for 4 h in air. The effects of the cutting tool inserts' microstructures on their mechanical properties and wear performance were carried out. The microstructural observations show that the Al2O3 grain size is significantly dependent on the amount of Cr2O3 additives used. The Vickers hardness and fracture toughness tests are directly related to the results of wear area, where the cutting insert with the minimum wear area also showed the highest hardness and fracture toughness. The results show that an addition of 0.6 wt% of Cr2O3 produces the minimum wear area. ZTA cutting inserts fabricated with Cr2O3 additives show an increase of 26% in wear resistant capability. (C) 2011 Elsevier B.V. All rights reserved.