Meiling Dong

The mechanical and corrosion resistance properties of Ti/TiN multi-layer films produced by physical vapor deposition

Purpose – The aim of the present paper is to investigate the mechanical performance of multi-layer films. With the wide application of optic and electronic thin-films, membrane materials and membrane technology have become one of the most active fields of research in contemporary materials science (Dumont et al., 1997). Multi-layer films have evolved as candidates for these applications because of their unique properties. TiN and Ti/TiN multi-layer films were fabricated using the DC magnetron sputtering method. A nano-indentation tester and electronic film distribution tester were utilized to evaluate the mechanical properties and residual stress of the films. The existence of interface effects on the mechanical properties and corrosion resistance of the films were analyzed. Design/methodology/approach – In this study, the Ti/TiN multi-layer films were fabricated using the DC magnetron sputtering method. The films were deposited on polished 45# steels. Ti was used as the sputtering target. Ar and N2 were ...

Effect of Different Substrate Temperatures on Microstru- cture and Residual Stress of Ti Films

Abstract The influence of different substrate temperatures of Ti film prepared by the direct current (DC) magnetron sputtering on the internal residual stress of Ti film were investigated experimentally by nanoindentation technique including Suresh model and Lee model. The results of the nanoindentation method and the curvature method were compared. At the same time, the surface morphology and the microstructure of Ti film were analyzed using atomic force microscope (AFM) and X-ray diffraction (XRD). The results show that the residual stress value obtained by Suresh model is almost the same as that by the curvature method, so the Suresh model is more suitable for calculating the residual stress of Ti films. Together with the nanoindentation data and micro-structure analysis, it is found that with the substrate temperature rising, the grain size of Ti films increases first and then decreases; the residual stress of the Ti film changes from the compressive stress to the tensile stress.

Effect of surface nanocrystallisation on the microstructure and wear resistance of vacuum carburised alloy

ABSTRACT In this work, a nanocrystallisation surface layer with an average grain size of 29 nm was fabricated on the 12Cr2Ni4A steel by the supersonic fine particles bombarding (SFPB). The vacuum carburising process was carried out on the original and the SFPB pre-treatment samples. X-ray diffraction, scanning electron microscopy and hardness tester were employed to study the phase constituents, grain size, hardness and residual stress of the two carburised samples. Experimental results showed that compared to the coarse-grain carburised layer (without SFPB), the carburised layer with SFPB pre-treatment has smaller martensite and carbide, and its thickness, hardness, compressive residual stress and wear resistance have been significantly improved. The dominant wear mechanisms of the two carburised samples were both abrasive wear and fatigue wear.