EFFECT OF HEAT TREATMENT OVER THE ELECTROCHEMICAL, MECHANICAL AND TRIBOLOGICAL PROPERTIES OF THE CR-DLC COATING

Diamond Like Carbon (DLC) with both sp3- and sp2-bonded carbon in DLC coatings is equipped with superior mechanical, tribological, electrical, and optical qualities. Depending on their composition and synthesis method, DLC films can be amorphous, hard, or strong. High residual stress in the film, however, limits its potential uses in many fields and results in poor adherence to the substrate materials. Increasing the deposition temperature, post-synthesis annealing, and vacuum furnace heat treatment are some popular techniques to lower residual stress. In this work, a DC magnetron sputtering method was used to create Cr-DLC thin films on silicon (100) substrates. Atomic force microscopy (AFM) and electrochemical testing, and nanoindentation test were used to assess the mechanical attributes of the thin film prior to production. According to the corrosion test, the annealing temperature increased corrosion resistance. The coating's young's modulus (E) and nanoindentation hardness (H) were computed. The internal stress of the produced coating was determined using Stoney's equation. The Cr-DLC coating was heat treated in a vacuum furnace at temperatures ranging from 270 to 360°C. Following heat treatment, nanoindentation was used to characterize the coating once more in order to evaluate its mechanical properties, such as H and E. The findings demonstrated that raising the heat treatment temperature to 360°C considerably reduced the coatings' residual stress. In contrast to the coatings' H and E decreasing, the residual stress of the coating heat treated at 300°C was somewhat reduced. From the electro chemical analysis, it was clearly understood that by increasing the temperature the corrosion resistance (CR) of Cr-DLC coatings' is increased up to 330°C. However, with the rise in temperature to 360°C the CR started decreasing.