The erosion behaviors by repeated impacts with a particle (steel ball of 4mm diameter) on the same material surface has been investigated to make clear the mechanism of sand erosion. The effects of impact velocity (V) and angle of attack (α) on erosion damage were discussed. The material used was polymethyl-methacrylate, and the impact velocity of particle was varied from 12 to 24m/s, and the angle of attack was from 40 to 80 deg.
From the observation of behaviors of crack growth caused by particle impact, it was found that the new ‘erosion factor’ presented as f=V3.6·sin2.8α·cos0.8α would be very useful in understanding the erosion behavior, and it was concluded that the ‘erosion factor’ was closely related to the energy given to the material by impact.
Moreover, the ‘erosion factor’ was found to be applicable for erosion by multiple particle impacts if ‘f’ was generalized as f=Vn·sinn1α·cosn2α (where n=n1+n2). A linear relationship was held between the erosion rate (R) and ‘f’. By using this new generalized ‘erosion factor’ the erosion rate under arbitrary condition could be estimated.