Effects of elastic modulus mismatch between coating and substrate on the friction and wear properties of TiN and TiAlN coating systems

TiN and TiAlN coatings deposited on copper, high speed steel and cemented carbide are used to study the effect of elastic modulus mismatch between coating and substrate on the friction and wear properties. Wear volume and failure mechanism are analyzed by optical profilometer, scanning electron microscope and focused ion beam techniques. It is found that the friction and wear properties of different coating systems are dependent on the substrate elastic modulus and hardness. Moreover, the wear performance of coating systems is related to the elastic modulus mismatch between coating and substrate materials. A weakening effect of substrate plastic yielding in hard coating system subjected to tangential loading is detected experimentally.