Three body abrasion wear behaviour of functionally graded aluminium/B4C metal matrix composite using design of experiments

摘要

Functionally graded aluminium metal matrix composite (Al-Si5Cu3/B4C) was fabricated through liquid metallurgy route followed by horizontal centrifugal casting method. The casting was obtained under the centrifugal die rotating speed of 1250 rpm and has the dimensions of length 150 mm, outer diameter 160 mm and thickness 20 mm. The microstructural test was performed at the surfaces those were at the distances of 3, 9 and 15 mm from the outer periphery of the casting. The tribological performance of the composite was studied using Design of Experiments. The wear experiments were conducted on the dry abrasion tester as per L_(27) orthogonal array using silica sand AFS 50/70 as an abrasive medium. The parameters such as load (28, 40, 52 N), speed (100, 150, 200 rpm) and distance (3, 9, 15 mm from the outer periphery of the casting) were varied for three levels. The response studied was wear rate and the wear performance was analysed by choosing "Smaller-the-better" characteristics. The influence of parameters such as applied load, sliding speed and distance from the outer periphery of the casting on the response was studied by using Analysis of Variance and Signal-to-Noise ratio. The results revealed that distance from the outer periphery of the casting has the major impact on the wear rate followed by load and speed. The worn out surfaces were subjected to Scanning Electron Microscope analysis and the wear mechanisms were observed.