Acceleration effect of a graphite dust environment on the fatigue crack propagation rates of Al alloy

An experimental set-up for the fatigue testing of Al alloy in dusty environments was developed and the effect of a graphite dust environment on the fatigue crack propagation behaviour of 2524-T3 Al alloy was investigated. The fatigue crack propagation rates (FCGRs) are higher for the sample in graphite dust especially at low Delta K-levels and tends to be similar to those in air with increasing Delta K. This acceleration effect of graphite dust is due to the lubrication of the absorbed graphite particles on the mating fracture surfaces which decreases the extent of crack closure and promotes microcrack growth.