The Additions of V and Cu on the Microstructure and Mechanical Properties of Mo-N Coatings

Abstract

Due to the excellent lubricity of V2O5 and soft metals, V and Cu have been added to Mo-N based coatings to further improve the tribological properties. In this study, the Mo-V-Cu-N coatings were deposited by high power impulse magnetron sputtering (HIPIMS). The effects of V and Cu on the microstructure and mechanical properties of Mo-N coatings were investigated. With increasing V/Cu content ratio, the deposition rate decreased from 15.4 to 6.5 nm/min, and the microstructure transformed from a featureless structure into a dense columnar structure. At low Cu contents, less than 6.5 at.%, the Mo-V-Cu-N coatings exhibited a single solid solution phase of c-Mo2(V)N. When the Cu content reached 29.7 at.%, the Mo45V1Cu30N24 coating showed the lowest surface roughness of 2.0 nm, and the coating changed into a double-phase of c-Mo2(V)N and c-Cu. The adhesion strength gradually increased from 32.2 to 87.8 N with an increasing V/Cu content ratio. Due to the microstructure densification, a maximum hardness of 27.3 GPa was achieved for the Mo46V15Cu1N38 coating, which was accompanied by a high compressive residual stress.

Effect of V/Mo Atomic Ratio on the Microstructure and Mechanical Properties of MoVCuN Coatings

“…When the V/Mo atomic ratio increased, a greater number of accelerated V ions were directed towards the coating surface under substrate bias voltage, thereby enhancing the ion bombardment effect. Prior to coating deposition, the polished cemented carbide substrate showed a low surface roughness of 2.7 nm [ 12 ]. However, the surface roughness of the coatings increased sharply.…”

“…These ions were accelerated to bombard the coating surface under substrate bias voltage, thereby intensifying the ion bombardment effect. Strong ion bombardment increased the mobility of surface adatom during deposition, resulting in the formation of a dense and fine columnar crystal morphology [ 12 , 32 ].…”

“…Wang et al [ 10 ] reported that the MoN-V (22 at.%) coating demonstrated the highest hardness and the best wear resistance, as well as the lowest friction coefficient at 700 °C, which was mainly associated with the formation of lubricious glaze layers of V 2 O 5 and MoO 3 . Similarly, the addition of V into the Mo-Cu-N coatings also improved the coating hardness and wear resistance [ 11 , 12 ]. Due to the synergistic lubrication effect of MoO 3 , CuMoO 4 , and V 2 O 5 , an excellent wear performance was achieved at room temperature.…”

Electrolytic Co-Deposition Mechanisms, Texture Layers, and Residual Stresses in Nanocomposite Coatings Processes: A Review

“…The aluminum substrate goes through a series of chemical treatment processes that aim to change its surface's nature and enable adhesion of the coated Nickel on the substrate, as Nickel will not reside on oxides. The four substages of pre-coating are alkaline degreaser, alkaline etching, acidic etching, and zincating [1].…”

“…Hence, aluminum is lighter and has a higher strength-to-weight ratio than steel, even if it has lower wear resistance. Aluminum 2024-T3 alloy contains 4% -5% Cu [1] [2] [3] [4]. Corrosion of this alloy can be accelerated due to a galvanic pair created between Al and Cu.…”