Sintering for Grinding Swarf of Bearing Steel by Pulsed Electric Current Sintering

This paper deals with sintering behavior of grinding swarf of bearing steel, which abundantly discharged while ball or roller bearings are manufacturing. The grinding swarf is investigated whether it is possible to use as P/M raw materials applied to machinery parts. Two kinds of sintering processes were used as a powder forming method, that is pulsed electric current sintering (PECS) and vacuum sintering (VS). The effects of sintering temperature and pressing pressure in the sintering on their mechanical properties and microstructure were evaluated. The density for PECS materials was higher than that for VS materials. In addition, the bending strength for PECS materials with high density was extremely higher than that for VS materials. It is concluded that the PECS is a suitable sintering method for the grinding swarf to get high density and high strength materials.