Duplex treatment of AISI 304 austenitic stainless steel using rf nitriding and dc reactive magnetron sputtering of titanium

In this work, duplex treatment has been carried out using radio frequency (rf) plasma nitriding process and direct current (dc) magnetron sputtering of titanium. Nitriding of AISI 304 stainless steel, using rf plasma technique, created a thick modified layer of approximately 20 μm for short plasma processing time of 10 min. After nitriding process, a thin titanium nitride film has been deposited using dc magnetron sputtering of titanium for different nitrogen/argon gas pressure ratios. The treated samples were characterized via glow discharge optical spectroscopy, X-ray diffractometry, scanning electron microscopy, profile meter and Vickers microhardness tester. The elemental composition, thickness and microhardness values of the duplex treated layers are found to be gas composition dependent. The data shows that the microhardness of the duplex treated layer increases to 1.42 fold relative to the associate value of the nitrided one. Moreover, high deposition rate of 110 nm/min is obtained.