Dry sliding wear in high density Fe-2%Ni based P/M alloys

Dry sliding wear behaviour of Fe-2Ni-0.47C (material A) and Fe-2Ni-0.2C (ma terial B) powder metallurgy (P/M) alloys has been studied on a pin-on-disc wear tester using an alloy steel pin and disc of hardness HRC 62. The P/M a lloys in the as sintered (similar to 90 HRB) as well as in the hardened and tempered (similar to 30 and similar to 40 HRC) conditions were investigate d for their wear behaviour. Wear rate was found to initially decrease and t hen remain constant with sliding distance in all the materials, it being le ast for the specimen hardened and tempered to similar to 40 HRC, Optical mi croscopy was performed to characterise the basic microstructures associated with different heat treatments. SEM observations of the worn surface revea led plastic deformation with delamination of surface layers by subsurface c racks as the mechanism in the as-sintered condition. Microploughing and for mation of surface platelets and traces of their detachment was found to be the dominant wear mechanism for the hardened and tempered specimens. (C) 20 00 Elsevier Science S.A. All rights reserved.