Structure and properties of TiAlLaN coatings deposited at various Ar/N2 flow ratio using a mid-frequency magnetron sputtering system

TiAlLaN coatings were deposited on the cemented carbide substrates by mid-frequency magnetron sputtering system. The effects of Ar/N-2 flow ratio on the composition, structure, adhesion and hardness followed with elastic modulus and H/E ratio were investigated systematically. Results indicate that all the Ti/Al ratios of the coatings were higher than that of the Ti/Al ratio in the target; however, the Ti/Al ratio increased with the Ar/N-2 flow ratio changed. XRD patterns show that the intensity of (111) peak was elevated with the Ar/N-2 flow ratio increased. Meanwhile, the peak shifted to lower angles, which implied increases of the lattice parameter. The TiAlLaN coating under the Ar/N-2 flow ratio of 3:1 showed the best adhesion, the highest hardness and the lowest H/E ratio which indicated perfect wear resistance.