Wear corrosion behaviour of TiN coated tool steel

The increasing environmental restrictions on the use of coolants and lubricants make the introduction of aqueous liquids more and more attractive. Water has some advantages over organic liquids or emulsions such as better cooling capacity, easier production, maintenance, recycling and lower costs. The introduction of water in a wear contact may lead however to the appearance of new phenomena. The interaction of wear and electrochemical processes may result in positive as well as negative synergetic effects. For the investigation of the combined corrosion and wear behaviour of hard coatings, a ball-on-disk test machine was designed and constructed. Introductory tests indicate the relative importance of environment and testing parameters on the wear corrosion behaviour of TiN coated tool steels. By introduction of demineralised water in the contact point, wear damage can be significantly reduced, compared to wear testing in air