Investigation and optimization of properties of sintered iron/recycled grey cast iron powder metallurgy parts

In this work, the preparation of iron/grey cast iron powder metallurgy parts by recycling machining scraps using target jet milling method is studied. Cast iron powder percentage, compaction pressure, sintering temperature and sintering time are selected as input process parameters. The effects of selected parameters on the response density, transverse rupture strength and hardness of the sintered samples are investigated by response surface methodology, and optimal combinations of input parameters are obtained. Analysis of variance and regression analysis are used to determine the main and interaction effects of input parameters, develop mathematical models and evaluate the validity of the models. Scanning electron microscopy and optical microscopy micrographs are provided to discuss the obtained responses. The results evidenced that the combination of iron/jet-milled grey cast iron is promising for producing powder metallurgy parts with diverse properties and economical considerations. Also, by comparing the optimized results obtained from the proposed models to that from the confirmation tests, the models errors were found to be in a range of 1%−8%.