Wear behaviour of alumina-toughened-zirconia composites with different phase arrangement under ball-on-flat tribological tests

ABSTRACTAn alumina-toughened zirconia (ATZ) material, fabricated using a procedure consisting of the common sintering of two different zirconia powders, was tested using the ball-on-disc method in a temperature range between room temperature and 400°C. Tetragonal zirconia balls were used as a counterpart. Two different types of microstructure were designed, one consisting of separated alumina inclusions in a zirconia matrix and another one which was a combination of two continuous phases, penetrating the whole volume of the composite. It was detected that at elevated temperatures both materials showed a distinct decrease in the wear rate. Composite with a low alumina content showed minimal wear rate at 300°C and composite with higher amount of alumina showed it at 400°C. There are some observations that this minimal wear rate result is connected with a pseudoplastic behaviour of a layer formed between co-operating elements of tribological pair. This layer is composed of the debris of both, sample and counterpart, and its behaviour during sliding is connected with the mean grain size of this debris which is correlated with the mean grain size of sintered material.KEYWORDS: Alumina toughened zirconiaTribologySliding wearBall-on-disc test Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis work was supported by subvention of the Polish State Ministry of Education and Science for AGH University of Science and Technology under projects 16.16.160.557 and 16.16.130.942. Tribological investigations were performed in Laboratory of Tribology and Surface Engineering of Department of Machine Design and Technology of AGH University. Microstructural investigations were performed in Laboratory of Scanning Electron Microscopy and Microanalysis of Faculty of Materials Science and Ceramics of AGH University.