Effect of impinging velocity on the erosive wear behaviour of polyamides

Various parameters, such as type, size and velocity of erodent and impact angle, are important for the erosive wear behaviour of materials. In this work, the erosive wear behaviour of various polyamides (PAs), viz. PA 6, PA 66, PA 66/610, PA 11, PA 12 and aromatic PA with difference in the methylene to amide (CH2/CONH) ratio in the backbone, was evaluated at two impact angles (30° and 90°) and at two impact velocities (80 and 140 m/s) using silica sand as erodent. The influence of impact velocity on erosion rate was more dramatic at an oblique impact angle (30°) than at normal impact angle (90°). Microscopic analysis of the eroded samples revealed that brittle fracture was the principal mode of failure in all the PAs at the normal impact. At the oblique impact, on the other hand, chipping off of material by microcutting and severe plastic deformation were observed.