abstract
In this work, aluminium based matrix composites with functionally graded properties are tested against cast iron in a pin-on-disc tribometer. SiC particulate reinforced F3S-20S aluminium matrix composite (Duralcan) was melted and centrifugally cast in order to obtain a gradient regarding the ceramic particle area fraction and mean particle diameter. Three different cross sections of the functionally graded material were considered for tribological characterisation. Friction and wear tests were performed at room temperature, constant sliding speed (0.5 ms(-1)) and at 5 N of normal load. The morphological features of the sliding surfaces were analysed by SEM/EDS in order to understand the prevailing wear mechanisms. The wear coefficient was relatively low for both matting surfaces (in the order of 10(-6) mm(3) N(-1)m(-1)), with the composites presenting the lowest wear values due to the combined effect of reinforcing particles as load bearing elements and the formation of protective adherent iron-rich tribolayers. A comparative analysis is established between the functionally graded properties of the aluminium based composites and the tribological response at different cross sections. Results suggests that there is a critical area fraction of SiC particles above which severe wear, attributed to lack in fatigue strength, is observed.
keywords
WEAR BEHAVIOR; SLIDING WEAR
subject category
Materials Science
authors
Gomes, JR; Miranda, AS; Rocha, LA; Silva, RF
our authors
