In this study, all TiN coatings were deposited by cathodic arc evaporation (CAE) technique using a vacuum chamber with 70 cm in diameter and 70 cm in height (Fig. 3). A water-cooled metallic Ti- cathode with a diameter of 6 cm was used. Samples of stainless steel 304 L with dimensions of 30 30 2 mm3 were used as substrates for the deposition of TiN coatings. Before introducing into the vacuum chamber, these samples were firstly polished and then cleaned with acetone and propanol in an ultrasonic bath for 15 min. Some of the coatings were deposited under Argon gas (Ar) atmosphere in order to study the effect of introducing Ar on the performance of the resulted coatings. During the coating process for all samples, coating pressure was kept at 1 Pa (E7.5 103 Torr). However, the different substrate temperatures recorded (not imposed) during the coating deposition process are given in Table 1.
A universal indenter (Fisher hardness tester) was used to evaluate the Vickers Hardness and Young's modulus of the studied samples from loading–unloading curves. Twenty individual