Influence of surface topography on the surface durability of steam oxidised sintered iron

Abstract

Durability of surfaces has been reported as the main factor affecting tribological behavior of steam oxidised sintered iron. The presence of surface pores and their negative influence on load bearing capacity, suggest that surface topography might play an important role on the durability of the oxide layer. In this paper, the influence of compaction pressure and powder grade on surface topography, and as a consequence, its effect on the tribological behavior of steam oxidised sintered iron has been analysed. Specimens prepared from atomised iron powders with different sizes were compacted using 4 different pressures, sintered, and then subjected to steam treatment. Tribological characterisation was carried out in a reciprocating sliding wear test. Although the processing parameters affected the surface topography to a considerable extent, the main influence may be attributed to powder grade. A strong influence of surface topography on the durability distance, evaluated in terms of the evolution of contact resistance with total sliding distance, has been highlighted. Surfaces which were smoother and had high load-carrying capacity were always associated with a higher durability distance.

Fundamental characteristics of material removal and surface formation in diamond turning of porous carbon

“…Therefore, increasing feed rate will cause both surface roughness (S a ) and core roughness (Sk) to rise. Although increasing S a is not desired, increasing Sk is advantageous because it will improve the capability of carrying the load after initial running-in period for air bearings (Mello, 2005). The effect of depth of cut on Sk indicated the same trend.…”

“…This shows that despite of different cutting conditions, Spk is negligibly small. This fact demonstrated again that it is advantageous for using a diamond turned porous carbon surface in air bearing applications (Mello, 2005).…”

Tribological evaluation of self-lubricating sintered steels

“…Because of the remaining pores, sintered materials have worse mechanical and wear resistance than that obtained using standard metallurgical processes such as casting and forging [23][24][25][26]. However, some authors describe the pores as potential reservoirs of lubricants.…”