Behaviors of ZTA (zirconia toughened alumina) reinforced iron composites under impact abrasive wear conditions

Abstract

This paper reports our investigation of the behaviours of ZTA (zirconia toughened alumina) particle reinforced iron composite materials (ZTAp/Fe45) during impact abrasive wear tests. The samples were produced by vacuum sintering and tested on an MLD-10 Impact Wear Rig using Fe45 as comparative material. The results show that most ZTAp/Fe45 composites have higher impact wear resistance than Fe45 matrix material due to the impeding role of ZTA particles against the impact of SiO2 abrasives. The wear resistance of ZTAp/Fe45 composites firstly increases and then decreases with the increase of particle size of ZTA, achieving best performance when the ratio between average sizes of the ZTA particles and SiO2 abrasives approaches 0.5. The wear mechanisms of Fe45 matrix material are mainly micro ploughing, impact plastic deformation and fatigue induced flaking. The failure process and mechanism of the ZTA particles are that cracks nucleate and propagate preferentially along the phase boundaries between the alumina and zirconia, resulting in micro peeling-off in the double phase mixture zone and eventually the delamination of alumina grains.