Wear and Adhesion Optimization of Thin TiAlN Films by Structure Design

The structure of TiAlN and other thin films depends on the coating method, parameter variation and an eventual treatment of the coating after deposition. Concerning the coating process, reactive sputter and evaporation parameters influence structure formation as well as plasma driven chemical reaction on the substrate surface. Besides, crystal formation and agglomeration depends on energetic level and flow rates in the coating system, the kind and number of reactive partners, temperature and specific parameters of the coating plant. Post-deposition treatments on the other hand may influence the formation of residual stresses but not the crystallization of different phases within the complete coating. Besides, mechanical treatment may change the coating’s morphology which may be important depending on the application since sometimes a columnar structure is to be optimized in size, amount and location. Thus a homogeneous coating is not always the optimum solution. In the experiments presented here we investigated the wear properties of thin TiAlN films. They were post-treated by sandblasting and heating in order to reduce frictional forces between the contacting bodies or analyze the effects of elevated temperatures respectively. These wear properties were evaluated by turning of 42CrMo4V at low cutting speed.