Production of aluminium oxide particle rainforced aluminium matrix composites by mechanical alloy method and investigation of dry wear behavior

In this study, particle reinforced Al based metal matrix composites (MMC?s) were produced by mechanical alloying (MA) technique. Al2O3 particles were used as reinforced material. In the produced composites, the ratio of the reinforcing material of Al2O3 particle was chosen as 5 %, 10 % and 15 % by weight ratio. The metal powders produced by MA methods were prepared by mixing in a vertical ball mill for 1,5 and 3,5 hours at a rotational speed of 450 rpm. Mechanical alloyed Al-Al2O3 powders were compacted at 650 MPa. These blocks were then sintered at 600 °C for 2 hours in a pipe type of sintering furnace under a control of argon gas. The microstructural investigation of the composite specimens were carried out and the distribution of Al2O3 particles in the matrix was determined. Density, porosite, hardness of produced samples were carried out. Moreover, dry sliding wear behavior of Al-Al2O3 composite was investigated by using pin-on-disk technique. Scanning electron microscope (SEM) and energy dispersive X-ray (EDAX) analysis were used to characterize the worn surfaces of composites. The experimental results indicated that hardness decreased and weight loss increased with decreasing particle size. The weight loss also decreased significantly with increasing Al2O3 content in the composite because of its hardness. The density increased with increasing weight fraction and increasing size of particles, but it contained a little porosity. In vii addition, scanning electron microscopic observations of the worn surfaces revealed that oxidation and partical delamination were predominant in the unreinforced alloy, while plastic deformation was predominant in composites. Furthermore, plastic deformation increased with decreasing particle content. Howeover, there was little changes in smoothing mechanism with increasing Al2O3 content.