Microstructural characterization of the tool–chip interface enabled by focused ion beam and analytical electron microscopy

A method based on focused ion beam milling and analytical electron microscopy to investigate the nature of the tool–chip interface is presented. It is employed to study tool–chip interfaces of the rake face of a (Ti0.83Si0.17)N coated PCBN insert after turning of case-hardened steel. Analytical electron microscopy shows the presence of a smeared adhered layer on the coating, which consists of steel elements from the work-piece, oxygen, and Si and N, most likely originating from the coating.