High-Temperature Oxidation Resistance of CrMoN Films

Abstract

The CrMoN film is deposited on the surface of M2 tool steel using the closed-field unbalanced magnetron sputtering technology. We measured the surface morphology, composition, phase structure, hardness and film/base bonding strength of CrMoN film using a scanning electron microscope, x-ray diffractometer, nano-indenter and scratch tester after oxidation at room temperature, 500, 600, and 700°C for 1 h. The results of this study demonstrated that the crystal structure and mechanical property of CrMoN film at room temperature are maintained after oxidation at 500°C for 1 h. In addition, with the increase in oxidation temperature, there is an increase in the evaporation of MoO 3 on the film surface and the oxidation degree of the film along with the appearance of fine pores. Moreover, the mechanical property and film/base bonding strength of CrMoN film significantly decrease after oxidization at 700°C for 1 h.

Wear Resistance, Patterns of Wear and Plastic Properties of Cr,Mo-(Cr,Mo,)N-(Cr,Mo,Al)N Composite Coating with a Nanolayer Structure

“…With the introduction of molybdenum into the composition of the (Cr x ,Mo 1−x )N system, a substitution solid solution based on the cubic structure of CrN is formed, but with an increase in the content of Mo, a phase of γ-Mo 2 N is also detected. When the content of Mo is prevailing (69.3 at.%), a certain amount of the bcc-Mo phase also arises [35]. Changes in the phase composition of the coating also affect its mechanical properties.…”

“…Changes in the phase composition of the coating also affect its mechanical properties. In particular, the introduction of molybdenum into the composition of the system increases the hardness of the coating, but with an increase in the Mo content to 45 at.% and above, a decrease in hardness is detected [35,36].…”

“…On the one hand, if the content of molybdenum is too low, there is no noticeable change in the tribological properties since a sufficient amount of molybdenum oxide is not formed [48]. On the other hand, an excessive increase in the content of molybdenum (more than 45 at.%) leads to a decrease in the hardness of the coating [35,36,48]. The temperature threshold for the onset of active oxidation noticeably increases at a content of 17 at.% Mo [32].…”