Abstract
Cast iron with surface pores was made by decarburizing flake graphite cast iron with 4 mass%C and 3 mass%Si at 1123 K in air. The pores were then pressure infiltrated by molten metals such as pure aluminum, AI-12mass%Si alloy or pure zinc at about 100 K higher than liquidus temperature of each metal. The thermal conductivities of pored iron and infiltrated irons were measured. The thermal conductivity value decreased greatly from that of untreated flake graphite cast iron with decarburizing. The thermal conductivities of perfectly metal infiltrated irons were calculated. Pure aluminum infiltration decreased the value, but Al-Si alloy or zinc infiltration decreased thermal conductivity compared with untreated flake graphite cast iron. However, experimentally Al infiltrated irons did not exceed the value of untreated cast iron, because of remaining pores by imperfect filling. These results clarify problems of thermal conductivity control of cast irons with the decarburizing and /or pressure infiltration technique.
