Particle size effects on the slurry erosion of aluminium alloy (AA 6063)

The effect of particle size on erosion wear of aluminium alloy (AA 6063) has been investigated in a slurry pot tester. Eight different sized quartz particles with mean size varying between 37.5 and 655 mu m have been used. The wear specimens are rotated inside the pot at 3 m/s velocity with orientation angle of 30 degrees and 90 degrees in a sand-water mixture of 20% concentration (by weight). It is seen that the erosion wear increases with increase in mean particle size. Two distinct mechanisms are noticed for mean particle size above 200 mu m and below this size for the range of parameters under this investigation. It seems that a threshold kinetic energy of impacting particle may exist, which results in change in the wear rate at a particular particle size. The threshold kinetic energy for different operating conditions has been determined and its relation with the change in erosion mechanism is discussed. (C) 2009 Elsevier B.V. All rights reserved.