The Sillimanite reinforced metal matrix composites of 5, 10 weight percent was fabricated by vacuum casting method and their properties such as density, hardness, tensile and impact strength are reported. For comparison pure aluminum is taken into consideration and found that the addition of sillimanite reinforcement increase the hardness, tensile, impact strength only up to 5 wt.% after that there is no substantial improvement in the mechanical properties. The erosive behaviour of sillimanite reinforced aluminum metal matrix composites is evaluated at different experimental conditions. Alumina oxide is used as erodent materials. The varying operating conditions are the erodent velocity within 41, 72 and 100m⁄s, angle of impingement within 45, 60 and 90 degree on the prepared composite. It is witnessed that, at higher velocity, the erosion rate is higher irrespective of reinforced metal matrix composites and pure Aluminum. At lower impingement angle, the erosion rate of the pure Al is greater than the reinforced composites. The effect of addition of reinforcement reduces the erosion rate of the composites at certain level i.e. up to 5wt. % only; beyond this addition of reinforcement is not having any significant effect in the reduction of erosion rate. The erosion rate of 10 wt. % reinforced composites is higher than the pure Aluminum. A dimensional analysis is also performed to correlate the relation between the erosion rate and input parameters.

This paper presents the results of studies to understand the influence of hybridisation on mechanical and tribological behaviour as well as dry sliding wear of aluminium metal matrix composites. Sillimanite and boron carbide (B₄C) were used as primary and secondary reinforcements and pure aluminium was used as the matrix material. The composite was fabricated by using a vacuum assisted stir casting process. Different research instruments were used, including a scanning electron microscope with EDX spectrometer, a surface measurement device, a thermal image analyser, as well as a tribotester. The results show that tensile, impact strength and hardness of the hybridised composites are superior (a step ahead) than unreinforced and primary composites. The wear behaviour of the fabricated specimens was tested for the dry sliding wear behaviour under the load range of 10–50 N with the steps of 20 N for the sliding velocities 0.75, 1.5 and 2.25 m/s over a distance of 1000 m. The wear rate increased with load and decreased as the wt.% of reinforcement increased. The wear rate of the composite with 10 wt.% Al₂SiO₅ was approximately 44% lower than that of the composite with 5 wt.% Al₂SiO₅. The same dependence was noted for hybrid composite (5 wt.% Al₂SiO₅ + 5 wt.% B₄C)—the wear rate was approximately 50.8% lower than that of the composite with 5 wt.% Al₂SiO₅ under the same test condition. The friction coefficient decreased as the weight percentage of the reinforcement (Al₂SiO₅ and B₄C) increased due to the uniform distribution of the reinforcement on the surface of the composites. The main wear mechanism of the studied materials was abrasion wear. The wear mechanism of the composite had tribochemical type. It involved the oxidation and transfer of the material, which formed protective tribolayers ensuring an additional sliding process. The mechanism that played the main role in the wear process of the composites was a combination of abrasive, adhesive and oxidative wear.