Mechanical and structural properties of AISI 8620 steel TiN coated, nitrided and TiN coated+nitrided

The mechanical and structural properties of TiN-coated, plasma-nitrided and TiN coated–nitrided AISI 8620 steel were investigated. The plasma nitriding process was carried out under various conditions of temperature (500°C), time (1, 4, 10 h), and gas mixture (70% N2+30% H2) at 10-mbar working pressure. The titanium nitride coatings were deposited using a closed-field unbalanced magnetron sputtering system (CFUBMS). Nitrided, TiN-coated and TiN+nitrided sample surface were characterized using microhardness tests, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The highest microhardness (10 gf) was obtained at 500°C for 4 h nitriding time. The alloy nitrides produced (CrN, Mn4N) showed a stable condition at all nitriding times. The adhesion of nitrided+TiN coated sample was obtained at 4 h using a plasma-nitrided process.