Dry sliding wear behaviour of in situ Al–TiB2 composites

Aluminium matrix/titanium diboride reinforced (Al/TiB2) composites were fabricated by in situ process. The wear behaviour was studied by using a pin-on-disc wear tester at room temperature. The coefficient of friction and wear rate were calculated experimentally for the Metal Matrix Composites (MMC) prepared from the Al/TiB2 system. The wear properties of MMC has improved significantly as a result of formation of fine TiB2 particles which are more uniformly dispersed in the aluminium matrix. Furthermore, strong particle/matrix bonding in Al/TiB2 composites enables the in situ particles to be retained in the wear surface during sliding, thereby effectively resisting the shear deformation. The worn surface were analysed using Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectroscopy (EDS). This paper presents the relationship between various dominant mechanisms of wear that are observed to occur under different conditions as well as the anticipated rates of wear.

Wear rate against testing conditions at different loads. Figure shows the wear rate of Al/TiB2 composites obtained in different testing conditions under different applied loads. It is clear from the figure that the wear rate increases with the increase in the load for each condition. But the variation is more predominant in condition 14; it is clear from the figure, the increased content of TiB2 in the composites results in their increased wear resistance. Reduced wear rates were obtained when 6 wt.% of Al/TiB2 maintained at 900 °C casting temperature for 30 min at reaction time.Figure optionsDownload as PowerPoint slideHighlights
► Coefficient of friction and wear rate increases with increase in load.
► Maximum wear resistance for 6 wt % of TiB2 MMC at 30 min. reaction time and 900°C.
► Ironing mechanism dominated at mild wear regime.
► Ploughing dominated at severe wear regime.
► Delamination dominated at ultra severe wear regime.