Effectiveness of Machinability Enhancer in Responding the Machining of Common Sintered Ferrous Steels
The Fe-Cu-C family of steels are the most common materials used in producing powder metal components. After conventional sintering, these materials feature a microstructure composed of ferrite and pearlite with the diffused carbon content determining the ratio. The structure is also strengthened by copper as substitutional alloying element. As more than 95% of the matrix is constructed by the base iron powder, the chemistry (purity) and manufacturing method of the base iron powder are considered to play important role in the machinability. This study evaluated the machining responses of sintered Fe-Cu-C steels manufactured from different base iron powder grades and graphite additions to understand the contribution of the base iron and the ratio of ferrite and pearlite to the overall machinability. A commercial machining enhancing additive was selected to evaluate its effectiveness in improving the machining of such sintered materials made with the different grades of base iron powder.