Improved resistance of alumina to mild wear by aluminium titanate additions

The wear behaviour of an alumina (Al2O3)-aluminium titanate (Al2TiO5) composite containing 10 vol.% of second phase is studied and compared to that of single phase alumina. A careful control of the microstructure has been done in order to compare materials with similar alumina grain sizes. Wear tests have been performed on a pin on disk tribometer with an alumina ball as pin, at room temperature, under a normal force of 10 N and at sliding speeds from 0.06 to 0.15 m/s. Extensive analyses of the microstructural modifications due to wear have been done by a combination of field emission scanning microscopy and confocal microscopy. Mild wear conditions were attained for both materials. The main wear mechanism identified in both materials involves the formation of a hydroxide film and its cracking and delamination. The composite specimens presented increased wear resistance compared to the single phase ones. (C) 2013 Elsevier Ltd. All rights reserved.