الفهرس | Only 14 pages are availabe for public view |
Abstract In the present study, A356 aluminium alloy was reinforced with TiO2.particles using liquid metallurgy route (vortex method). In addition to the monolithic matrix alloy A356, two composite materials having 10% and 20% weight percents of TiO2 particles were prepared. The effect of the TiO2 particles weight percent on the microstructure, aging behaviour, hardness and wear resistance of the A356/TiO2 composites were evaluated. Examination of the microstructure of the composites showed that the porosity content of the composites is higher than the matrix alloy. Increasing the weight percent of TiO2 particles increases the bulk porosity of the composites. The top of the cast composite ingots exhibited the lower density when compared with the middle and bottom of the ingot. The bottom of the composite ingots exhibited the highest density. The hardness test results showed that, incorporation of TiO2 particles into A356 alloy increases the hardness of the alloy. The hardness of the composites increases with increasing of weight percent of TiO2 particles. An accelerated aging response was observed in composites. In general, it was found that the addition of TiO2 particles accelerates the aging kinetics and reduces the time required to reach the peak hardness. Dry sliding wear behavior of A356 aluminum alloy composites reinforced with the TiO2 particles were investigated by using a pin-on-ring wear tester. Pins of the composites were rubbed against SS 316 stainless steel ring at various sliding velocities and applied pressures. The wear resistance of composites was improved by the presence of TiO2 particles. The results obtained from wear tests showed that, the composites has better wear resistance as compared to the unreinforced A356 matrix alloy. |