Effects of Alumina Particles and Carbon Monoxide Gas Bubbles Within the Melt on the Graphite Morphology and Microstructure of Gray Cast Iron

In this study, the effects of adding of alumina particles and carbon monoxide gas bubbles through the runner system on graphite morphology and microstructure of gray cast iron was studied. To add alumina particles, thermite reaction of aluminum and iron oxide powders in runner was used and for production of carbon monoxide gas bubbles in runner, reduction reaction of iron oxide by carbon was carried out. Light microscopy, scanning electron microscopy and XRD were investigated. The burning of sand in chamber of powders provided that reactions were performed in according with the expected and their heat caused the sand burning of Microscopic evaluation showed that the addition of alumina particles has great influence on the graphite morphology. The presence of these particles in the liquid was cased heterogeneous nucleation of graphite and as a result, B type of graphite and Kish-graphite were produced. Alumina particles have no affected microstructure. Bubbles of carbon monoxide have no effect on the graphite morphology and microstructure.