Wear behaviors of PcBN milling insert in high-speed dry milling nodular cast iron

Nodular cast iron is an important material for internal combustion engines inside automobiles and tractors. However, its poor machinability, low efficiency, and severe tool wear during cutting limit the application to a certain extent. In this paper, a novel type of uncoated and coated PcBN milling inserts (C-PcBN) are used for high-speed dry milling of nodular cast iron. The effects of the cutting speed on the wear characteristics, mechanisms, and service life of the milling inserts are systemically investigated by comparing the counterparts of cemented carbide-coated milling inserts (C-YG) with the same model. Additionally, the relationships between cutting speed and the cutting force, temperature, system vibration, and service life are analyzed. The results revealed that the cutting speed has a significant influence on the cutting performance of the three milling inserts. PcBN and C-PCBN are superior to C-YG milling inserts in cutting performance with small wear amount, long service life, and low machining surface roughness value at high speed (more than 400 mm/min).