A New insight into friction transfer behavior of MoCN coatings: the tribo-activated formation of carbonitride based nano-twisted helix wear debris

Abstract

Molybdenum carbonitride coatings were deposited onto 304 steel substrate by magnetron sputtering method. A novel transition behavior of tribo-activated carbonitride based nano-twisted helix wear debris was discovered. The structure, mechanical and tribological properties of the coatings were investigated systematically. As the carbon content increases, the cross-sectional structure of the coating gradually becomes denser, while the hardness gradually decreases. Tribological test results show that the friction coefficients of 304 steel and MoN coatings are about 0.8–0.9, and both are mainly characterized by adhesive wear. With the increase of carbon content, the friction coefficient of the MoCN coating decreases gradually from 0.8 to about 0.55. The wear rate of the MoCN coatings is significantly influenced by the tribo-activated carbonitride based nano-twisted helix wear debris formed at the contact interface perpendicular to the sliding direction.

Investigation of the Al-Mo-B(CN) Coatings Deposited Using Magnetron Sputtering of Al-Mo-B4C Target Produced by Detonation Spray Coating

“…The elemental composition of the cross-sectional surface of the AlMo-30B 4 C coating is shown in Table 4. inclusions but without the columnar elements usually observed in Me-B (C or N) coatings [15,[49][50][51]. Due to the columnar structure of coatings, mechanical properties deteriorate due to the diffusion of oxygen from the surface into the depth of the material along the boundaries of columnar grains [1,[52][53][54].…”

“…Figure 4b shows a characteristic image of cross-section fractures in the coating deposited onto a monocrystalline silicon substrate. It can be seen that the coating (thickness ~1 µm) is characterized by a dense homogeneity with a structure featuring small drip inclusions but without the columnar elements usually observed in Me-B (C or N) coatings [15,[49][50][51]. Due to the columnar structure of coatings, mechanical properties deteriorate due to the diffusion of oxygen from the surface into the depth of the material along the boundaries of columnar grains [1,[52][53][54].…”