Effect of nano-sized TiN additions on the electrical properties of vacuum cold sprayed SiC coatings

Three different contents of nano-sized TiN powers of 20 nm in size were added to nano-sized SiC powders of 40 nm. Vacuum cold spray (VCS) process was used to deposit SiC-TiN composite coatings on Al ₂O ₃ substrates. Microstructure and phase structure analysis of the samples was performed by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Sheet resistance of the VCS coatings was measured using a four-point probe method. The influences of TiN additions on the electrical resistivity of SiC-TiN composite coatings and the conductive mechanisms were investigated. The electrical resistivity of SiC-TiN coatings decreases with increasing TiN contents, reaching a minimum of 1.82 Ω m with 50 mol% TiN.