Change in the Chemical Composition of a Carbide Tool with TI–Al–N Coating Surface Layers During Machining.

In this study the results of investigating the change in the chemical composition in the surface layers of cutting tools at the beginning of machining are presented. To describe this change, physical modeling, imitating the initial stage of machining and wear, is performed. The investigated samples made of TT8K6 alloy with a Ti–Al–N coating is thermally and mechanically loaded at 700°C by an applied pressure of 0.5 GPa for 20 minutes. This corresponds to the thermal and mechanical loads on the coating during machining. The change in the chemical composition in the surface layers of coated tools are investigated by glow-discharge optical emission spectroscopy analysis. A variation in the titanium, aluminum and oxygen content in the surface layers after modeling is described. Qualitative elemental composition profiles are presented. In addition, the microstructure of the samples obtained by scanning electron microscopy is presented. Element distribution maps are obtained. [ABSTRACT FROM AUTHOR]