MACHINING OF GRAY CAST IRONS AND COMPACTED GRAPHITE IRON

Paper in proceeding, 2007

Abstract: The aim of this paper is to compare the machinability of gray cast iron and compacted graphite iron (CGI), in terms of tool life and microstructure. Two gray cast irons with different graphite morphologies and one CGI were tested. After the tool life tests with carbide and Cubic Boron Nitride (CBN) inserts, microstructural changes on the machined surfaces was investigated and SEM analysis of the inserts were performed. The results show that CBN performed much better than Carbide tools when machining gray cast irons but did not work when machining CGI due to high diffusional wear. The shorter and thicker graphite flakes for one of the gray cast iron caused different chip contact and wear mechanism on the inserts. The comparison of machinability and tool wear gave better understanding of the wear mechanism of CGI.