Properties of surface layers produced on the Ti–6Al–3Mo–2Cr titanium alloy under glow discharge conditions

The recent rapid progress in surface treatment techniques requires that titanium alloys should have an improved resistance to frictional wear without any loss of their high corrosion resistance. These requirements can be satisfied by producing surface layers of specified microstructure and phase composition. The paper presents the results of examinations of the structure and properties of surface layers formed on the Ti–6Al–3Mo–2Cr titanium alloy by glow discharge assisted nitriding and modified process known as carbonitriding (characterized by an alteration of the gaseous atmosphere in which the process is conducted). The investigations included: metallographical examinations, determination the phase and chemical composition of the layers, measurements of their corrosion and frictional wear resistance and scratch tests. The carbonitriding process increases the hardness and improves the wear and corrosion resistance compared to the nitriding technique.