In this paper we studied the influence of pre-treating the surface of 100Cr6 steel by ion beam nitriding at low temperature (380°C) on the surface topography and wear resistance of thin TiN coatings deposited by reactive ion beam assisted deposition. The specimens were characterized by grazing incidence X-ray diffraction, scanning electron microscopy and atomic force microscopy. The wear resistance of the TiN-coated specimens was evaluated by means of ball on disc tests. The results showed that application of a preliminary ion beam nitriding treatment slightly increased the surface roughness but improved the wear resistance of the 100Cr6 steel due to the formation of a diffusion zone containing the γ'-Fe4N nitride combined with the TiN coating.

The current work presents a study of alternative methods of cooling-lubrication for the external plunge grinding of advanced ceramics using diamond wheels. These two alternative methods, which are intended to reduce cutting fluid expenses, are commonly referred to as the optimized cooling-lubrication method and minimal quantity of lubrication (MQL). The techniques were evaluated by process monitoring and by the assessment of output variables such as tangential cutting force, G ratio, roundness errors, surface roughness, microstructure and residual stresses measured by X-ray diffraction. The obtained results showed that the two proposed techniques can replace the conventional cooling-lubrication method, i.e., flood coolant. In particular, optimized cooling-lubrication method reduced wheel wear and produced workpieces with the best geometric and dimensional finishes, while MQL significantly reduced the amount of fluid employed in the process without harming the workpiece quality.