Characterization of TiN Coatings Deposited on H11 Tool Steel by PECVD Method

摘要

In this work, TiN nanostructured hard coating was deposited on the quartz and H11 hot work tool steel substrates using by plasma enhanced chemical vapor deposition (PECVD) technique. The process was performed in a hot wall chamber containing Ar, N-2, and H-2 gases along with TiCl4 vapor for 2 h at the temperature deposition of 470 degrees C. Field emission scanning electron microscopy (FE-SEM) and EDS were used to determine thickness and chemical composition of the coating, respectively. Crystal structure of the coating was investigated by X-ray diffraction (XRD) technique which indicated strong reflections of highly crystalline TiN. This was further confirmed by X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectrometry (RBS). Potentiodynamic polarization test in 3.5% NaCl solution and pin-on-disc were used to evaluate the properties of the TiN coating. The results indicate that specimens coated with TiN coating has fine columnar grains and low friction coefficient (about 0.2). Also polarization curve exhibit a 10 times improvement in corrosion resistance compare to uncoated samples. This protection is attributed to formation a dense and adhesive layer of TiN nanostructured hard coating on the H11 substrate.