Continuously Growing Ultrathick CrN Coating to Achieve High Load-Bearing Capacity and Good Tribological Property

Abstract

Continuous growth of traditional monolayer CrN coatings up to 24 h is successfully achieved to fabricate ultrathickness of up to 80 μm on the 316 stainless steel substrate using a multiarc ion plating technique. The microstructures, mechanical properties, and tribological properties evolution with the CrN coating continuously growing was evaluated in detail. The transmission electron microscopy observations and inverse Fourier-filtered images reveal a relaxation mechanism during the continuous growth of CrN coating, which can lead to a decrease in the residual stress when coating growth time exceeds 5 h. The scratch test and friction test results both show that the load-bearing capacity of coating is significantly increased as CrN coatings growing thicker. During the scratch test, the ultrathick CrN coating of thickness 80.6 μm is not failed under the load of 180 N, and the dominant failure mechanism is the cohesive failure including wedge spallation and cracking. The dry-sliding friction test results show the mean coefficient of friction and the wear rate of ultrathick CrN are respectively decreased by 17.2 and 56.8% at most compared with the thin coating (thickness is 5.4 μm). The ultrahigh load-bearing capacity and excellent tribological property are attributed to the relaxation mechanism and limited contact pressure as the coating grows continuously.

Design of Fe-Based Bulk Metallic Glasses with Improved Wear Resistance

“…On the contrary, other studies , indicate that the maximum shear stress would appear at the surface rather than below it, and the observed cracks originated at the surface and then propagated in the subsurface region before they emerged again on the surface. To verify whether the cracking originates from the large contact stress induced by normal loading, we theoretically calculated the stress state with a ball-on-plate contact configuration according to the Hertzian contact model. , On the basis of the materials parameters (e.g., Poisson ratio v Si 3 N 4 = 0.26 and v BMG = 0.316; E Si 3 N 4 = 320 GPa and E BMG = 223 GPa) and wear conditions (normal load of 40 N and sliding speed of 5 mm s –1 ) adopted in this study, the maximum contact stress and shear stress were calculated to be 2.47 GPa and 755 MPa, respectively, at a position of around 40 μm beneath the surface. The values of the maximum contact and shear stress are much less than the fracture strength of the BMGs studied (∼4.0 GPa).…”

Mechanical Properties of Nanostructured CoCrFeNiMn High-Entropy Alloy (HEA) Coating

“…In the past decades, binary Li et al, 2018), ternary (Yao et al, 2015; and quaternary Wang et al, 2017) transition metal nitride or carbide coatings have been well explored and applied in many industrial and engineering fields. These coatings possess very high hardness, but their brittle property has impeded its application in certain areas, such as automotive parts, mold, tools etc.…”

Preparation and tribological performance of CrAlTiCN coatings on 316L and TC4 substrates in sea water

“…Compared with the pure CrN coating [8], the surface of CrAlTiCN coating is denser, and the grain size tends to decrease. The reason is that Al, Ti and C atoms enter the CrN crystal structure to replace the Cr or N atoms, which hinders the crystal growth and refines the grain size [28]. Figure 3(c) shows the cross-section micro-morphology of CrAlTiCN coating.…”