Machinability study on dry machining of white cast iron by polycrystalline cubic boron nitride inserts

Abstract The polycrystalline cubic boron nitride (PCBN) insert has been widely used in machining high chromium white cast iron (HCCI), which has the high hardness and abrasiveness. The aim of this article is to reveal that micro-mechanical properties play an essential role in assessing the machinability of high chromium cast iron. Grid nanoindentation is applied to measure the micro-hardness distribution. Based on grid nanoindentation results, the micro-hardness distribution is proposed to study the machinability. After the machining test of HCCI by the PCBN insert, the cutting force, tool wear, surface roughness, and chip formation showed that the micro-hardness distribution of materials has the better results than macro-hardness in machinability evaluation, and abrasive wear occurred on the rake and flank face of the cutting tool. The abrasiveness index that is related with the micro-hardness distribution and the abrasive wear effect in machining, for the most of high abrasion materials, has the possible to evaluate the dynamic cutting process and tool life in dry machining by using the PCBN insert. The micro-hardness distribution imported into the machinability model may propose a new way to improve the data exchange capability in the modern manufacturing process.