Investigation of atomic and electronic structure of films generated on a cutting tool surface

It is established that oxygen-containing films named as secondary structures (SS) are developed on the surface of deformed composite powder material based on high-speed steel (HSS-based DCPM) tools during their operation at cutting. The composition, nearest atomic surrounding, and electronic structure features of these films were investigated by means of SEM, AES, ELS, and EELFS methods. It was found that structural features of these films differ from those of TiC, TiO2 (rutile), and films formed on the surface of the TiC powder heated in air. Disordering of atoms at long interatomic distances (beyond the third coordination sphere) and low localisation of ir-electrons make it possible to arrive at a conclusion on the amorphous-like structure of the films. Evolution of the atomic structure of DCPM tools at friction was revealed. It was discovered that favourable frictional properties and a high wear resistance of DCPM tools are followed from developing SSs that consist of the oversaturated solid solution of oxygen in titanium that possesses metal-like characteristics. (C) 1999 Elsevier Science B.V. All rights reserved.