Investigation of green properties of iron/jet-milled grey cast iron compacts by response surface method

Grey cast iron powder was produced from grey cast iron scraps by jet milling method and mixed with commercial pure iron powder. The morphology of the produced powders and characteristics of the powder mixtures were investigated. The mathematical models were successfully developed to predict green properties of iron/jet-milled grey cast iron compacts using response surface methodology. Using response surface methodology, the effects of the percentage of jet-milled cast iron powder and compaction pressure on green density, green strength, and hardness of the green compacts were analyzed and the optimal combinations of the input process parameters were obtained to maximize the responses. The main and interaction effects of the input process parameters and also the validity of the models were evaluated by using analysis of variance method. Scanning electron microscopy micrographs of the powders and the fracture surfaces were provided to discuss the obtained responses. The results indicated that in addition to fast production rate and economical considerations, the iron/jet-milled grey cast iron powder compacts have adequate green properties for most of the different combinations of the input process parameters.