Fretting wear of sintered iron under low normal pressure

Abstract

Fretting wear of sintered irons of relative density 80%, 85% and 90% under a low normal pressure of 2 MPa has been investigated. Wear was generated in air, with no lubrication, between test-pieces of the same density. The nominal contact area was (100 mm) 2, normal load was 200 N and average sliding speed was 0.01 ms −1. Three different peak-to-peak sliding strokes, 0.05 mm, 0.2 mm and 0.5 mm were used with the corresponding total number of sliding cycles of 10 6, 2.5×10 5 and 10 5 respectively. All the three materials gained mass but lost volume under all test conditions. Both mass gains and volume losses decreased with increasing density, but increased with increasing stroke. Mass and volume changes can be interpreted by a model involving packing of debris into surface breaking pores. Density had no significant effect on friction coefficient. Higher friction coefficients always coincide with higher frequency and lower sliding stroke even though the amount of wear changed in the opposite sense.