Influence of Si content on structure and mechanical properties of TiAlSiN coatings deposited by multi-plasma immersion ion implantation and deposition
(State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China)
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