Aluminium-alloy transfer to a CrN coating and a hot-work tool steel at room and elevated temperatures

The results show the strong dependence of the tribological properties of the hot-work tool steel and the CrN coating with respect to the aluminium alloy for the temperature together with a limited dependence on the sliding distance. At 20 °C the surface roughness was found to be the main initial cause of the aluminium alloy's transfer via mechanical interlocking. At higher temperatures (400 °C), this transfer occurred predominantly due to strong adhesion. However, at the highest tested temperature (500 °C) the CrN coating showed a notable decrease of the adhesion with a consequent reduction in the transfer of the aluminium alloy and limited transfer-film formation.