An investigation of the nanoindentation and nano/micro-tribological behaviour of monolayer, bilayer and trilayer coatings on cemented carbide

The mechanical and tribological properties of monolayer TiCN, bilayer Al2O3–TiCN and trilayer TiN–Al2O3–TiCN coatings on cemented carbide substrate have been investigated. Mechanical properties have been determined by nanoindentation and tribological properties assessed by micro-scratch and nano-impact testing. The trilayer system shows improved performance in the scratch and impact tests despite its outermost coating layer having the lowest H/E ratio. The importance of the ratio of elastic to plastic deformation during indentation (composite H/E) of these systems on their behaviour in nano-scratch and nano-impact tests is considered.