Effect of heat treatment on the wear behavior of zircon reinforced aluminium matrix composites

Effect of heat treatment on the wear behavior of LM13/zircon reinforced composites have been studied. Stir casting process was used for the fabrication of composites with 10 wt% fine and coarse zircon particles. Further, T4 and T6 heat-treatment were carried out on the composite specimens. The hardness of the fine particle sized composites was superior in comparison to coarse particle sized composites. For T4 heat-treatment, maximum hardness of 201 BHN was obtained after natural aging of 20 days, beyond which the hardness value remained near-about constant. For T6 heat-treatment, maximum hardness of 212 BHN was observed for the artificial aging at 180 °C for 4 h. Maximum improvement in hardness (over the non-heat treated composites) observed for T6 a fine and T6 coarse composite was 15% and 13% respectively. Further, heat-treatment decreased the wear rate of the composites. Best results were obtained for T6 heat-treated composites. A maximum reduction of 25% and 27% (over the non-heat treated composites were obtained for T6 heat-treated coarse and fine samples respectively. Finally, SEM analysis revealed that abrasive wear mechanism was dominant for lower contact pressures (0.2 MPa). Whereas, for high contact pressure (1 MPa) adhesive wear mechanism was dominant.