The use of physical vapor deposition (PVD) for hard coatings, especially Al 2 O 3 , TiN, and CrN coatings, has been considered as an ideal method in the coating. Among hard compounds, TiN, due to high hardness, high chemical and physical stability, and low electrical resistance, has been utilized as a popular coating in the industries in the recent decades. [1][2][3] The significant decrease in the TiN coating hardness, its low resistance to oxidation at temperatures higher than 500°C (work temperature restriction), and its low corrosion resistance to corrosive environments are, however, among the most important disadvantages of this coating. 4,5 CrN coating has been introduced as an appropriate substitute for TiN. This is because of the higher fracture toughness, more corrosion resistance and also a lower friction coefficient for the CrN coatings, as compared to TiN coatings. One of the most noteworthy disadvantages of CrN coatings is their low hardness. Many studies have been carried out to improve the CrN hardness. 4,6 In this regard, multicomponent and multilayer coatings have been studied; by producing CrAlN, TiCN, TiAlN, and TiCrAlN new coatings, a significant step has been taken toward the development of hard and corrosion-resistant coatings. 7-10 Addition of aluminum to transition metal nitrides has led to a new group of hard coatings improving oxidation and corrosion behavior, thermal stability, and their hardness. [11][12][13][14][15][16] Triple nitride coatings on the Cr base can prevent oxygen diffusion into the coating by forming dense protective oxides like Cr 2 O 3 and Al 2 O 3 , improving the corrosion properties of the coating. Also, chrome oxide layers are denser than titanium oxide layers, so nitride coatings on the chromium base can have a higher corrosion resistance. 5,17,18 Hence, more advanced coatings, like CrAlN multilayer coatings, have a better performance than the simple nitrides. 12,[19][20][21][22] It has been found out that