Tribological behavior of DLC and hard coatings against aluminium based materials

The use of high-strength aluminium alloys for massive forming parts plays an increasing role in lightweight construction. The usage of less/without lubricant during massive forming and tool surface modification operations are significantly important because of the economical and ecological aspects. Selection of the high wear resistance material, which is in contact with high-strenght aluminum alloys, is curial for improving the service life of the forming tools. In this study, coatings were deposited on steel substrate 1.3343 (HS6-5-3) by PVD (Physical Vapour Deposition) and CVD (Chemical vapor deposition) techniques. The frictional behaviour of coating systems was characterized by a pin-on-disk tribometer with and without lubricant conditions. Surface profilometry was used to compare the surface topography of the coatings. The coating systems doesn't show remarkably tribological improvement in comparison to the steel 1.3343 under lubricant conditions. Wear test results showed that the DLC-based coatings reduce the friction coefficient by up to 74% compared to steel under dry conditions. It has been found that the best performance of tribological system without lubricant improved with the type of plasma nitriding + DLC coating system.