Self-lubricating bearings: microstructural and dimensional evolution under industrial processing conditions

摘要

In the aim of understanding the behaviour of microstructural and dimensional evolution in the industrial practice, a self-lubricating bronze bearing alloy and different part geometry were studied under industrial sintering conditions. Theelemental mixes were made in a "Y" mixer; and the parts were sintered in a push-pull furnace. Some compacts were also sintered in a batch furnace, a dilatometer; and a differential thermal analyser (DTA) with the purpose of understanding the reactionsthat occurred during heating and sintering. So, dilatometries at different heating rates, DTA with different densities and the microstructural evolution during the industrial sintering cycle are presented. The parts sintered in the batch furnace had their dimensions measured and the influence of density, temperature and velocity of passing through the furnace on final dimensional change are reported. The results obtained showed that the sintering cycle, part geometry and density affect the microestructural evolution, strength and dimensional variation. The usual strength were easily obtained showing that the dimensional accuracy shall be the focus of processing control.