Researches On Preparation And Mechanical Properties Of Multifunctional Cr Doped Diamond-like Carbon Films

Diamond-like carbon film is composed by diamond phase (sp3 carbon hybrid structure) and graphite phase (sp2 carbon hybrid structure), which makes it have many excellent performance, such as high hardness, low friction coefficient, good light transmittance, stable chemical properties and good biological compatibility. DLC film is a new type of film material that can be widely used in mechanics, optics, electronics, biomedical and other fields. However, in the process of research and application, the defects of DLC films like high internal stress, poor toughness and thermal stability weaken its performance and lifetime. To improve these detects, researchers have been done a series of studies and find that methods, including basal surface pretreatment, doping heterogeneous elements, using interlayer film, annealing treatment, all can improve the performance effectively.This paper focus on the effects of Cr doping, Cr interlayer designing and the synergy of the previous on the structure and properties of DLC films.The films are deposited by the different arc (pulse cathode arc and DC arc cathode) evaporation technology. The pulse cathodic arc generator can be used to evaporate graphite target to prepare DLC films. DC cathodic arc generator with the magnetic separation device can be applied to evaporate Cr metal target to do Cr element doping and Cr interlayer deposition. In this paper, DLC, Cr/DLC, DLC:Cr and Cr/DLC:Cr were deposited on silicon and stainless steel substrates. Raman, XPS, AFM and SEM were operated to analyze the phase microstructure, element content and surface morphology, respectively. Nano indenter, atomic-Profiler, friction-abrasion testing machine were used respectively to measure the hardness and elastic modulus, thickness and the internal stress, friction performance. And the wettability and corrosion resistance were also tested. Through comparison, the influence of pulse frequency, DC cathode arc and Cr interlayer on the element composition, microstructure and properties were explained, which provides theoretical basis for DLC films application.