Response of aluminum alloys to multiple particle impacts

Samples of annealed 1100 aluminum and 7075-T6 aluminum were eroded to steady state conditions in a multiple particle erosion tester. The samples were sectioned through the eroded areas, and a mechanical properties microprobe was used to measure the hardness of the material. A rippled surface developed as a result of the oblique impacts, and the hardness at the top of a wave crest was approximately equal to that in the valleys. However, the total depth of hardening (as measured from the surface of the specimen after impact) was significantly greater in the wave crest and was a function of the material for both wave crests and valleys. The depth of hardening in the valleys was approximately equal to that for single impacts.