New Method for the Development of Porous Gray Cast Iron Castings

The presence of porosity in castings is usually considered a defect and raises concern about the quality of the material. However, porous metals are extremely useful in specific applications because of their peculiar combination of physical and mechanical properties such as a high strength to weight ratio with good energy absorption characteristics. There has been considerable interest in these properties for industrial applicability and scientific viewpoint. Since the inception of metal foam, several processes have been developed to introduce large size pores, almost uniformly distributed, in metallic materials. This paper covers the formation of porosity in cast materials, especially in gray cast iron. It also summarizes the experimental work done to investigate the possibility of forming porous structures along with the inspection methods to confirm the pores formed in and throughout the casting. The density and percentage porosity of the produced castings are presented.