Abstract:TiAlSiN nanocomposite coatings were prepared by multi-plasma immersion ion implantation and deposition (MPIIID). The chemical composition, microstructure and mechanical properties of these coatings were investigated by energy dispersive X-ray (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nano-indentation and scratch tests. XRD patterns reveal that the main reflection in the as-deposited coating corresponds to a strong TiN (200) preferred orientation. XPS results show that AlN, Si₃N₄, Al₂O₃ and Ti₂O₃ are also formed in the coating. Comparing with the TiN coating, when the Si content in the coating is 0.9%, the film shows an increased hardness of 32 GPa, while its fracture toughness and adhesion strength are weak. When the Si content is increased to 6.0%, the coating exhibits a super hardness of 57 GPa as well as excellent fracture toughness and adhesion strength.

Key words: TiAlSiN; ion implantation; deposition; structure; nanohardness