Tribological behaviour of titanium alloy modified by carbon–DLC composite film

In sheet metal stamping, galling is initiated and developed aggressively at the mould radius, where sheet metal undergoes large plastic deformation. This study sheds light on correlating the level of sheet plastic deformation with galling initiation on the mould surface. The 3D topography facilitated the observation of galling evolution process on the surface of quenched/tempered mould. The observation on the sliding sheet counterpart showed that with larger plastic deformation, zinc-coated surface tended to become rough and a large number of intermittent micro-cracks formed, leading to earlier initiation of galling. Furthermore, the surface of mould was treated by physical vapour depositing (PVD) of CrN. In the specific sliding tests under the same level of plastic deformation, critical total slid distance at which galling initiated was increased significantly. The major factor causing galling initiation on the PVD(CrN)-coated mould was identified.

Section: Performance Of Galling Resistance Of Pvdtreated Mouldmentioning

confidence: 99%

Developing of galling during the forming and its improvement by physical vapour depositing

Zhou

Gao

Zheng

et al. 2018

“…Moreover, relatively low adhesion strength was also one of the important factors that resulted in a relative high wear rate. 28,29 12 Worn surfaces of the four types of GLC films…”

Section: Effect Of Thermally Driven Processmentioning

confidence: 99%

Structure and properties of GLC films deposited by PEMS

Yong¹,

Guo²,

Wang³

et al. 2016

In this paper, an unbalanced plasma enhanced magnetron sputtering system was adopted to deposit four types of the graphite-like carbon (GLC) films under different currents of ion source. The results show that a moderate Ar + bombardment effectively adjusts the content of sp 3 hybrid structure, and significantly improves the film's compactness. With the increase of ion source current, the hardness, H/E and H 3 /E 2 ratios of the film present a change rule of increasing first and decreasing subsequently, and all achieve their maximum values under the ion source current of 10 A. Moreover, the average values of the studied GLC films are all below 0.05 with slight fluctuation, while the wear rate of the film presents a significant difference with the increase of ion source current. Especially, when the ion source current is 10 A, the friction coefficient and the wear rate of the GLC films are 0.01 and 1.7 × 10 −16 m 3 N −1 m −1 , respectively, presenting excellent tribological properties.

“…It demonstrates a low friction coefficient, high wear resistance, high hardness, chemical inertness, hydrophobicity, and excellent corrosion resistance [6][7][8]. The friction coefficient of DLC films can be as low as 0.1-0.15 [9]. DLC films are usually used as hard and solid lubricating coatings for tools and anti-friction and anti-corrosion films for electromagnetic parts.…”

Section: Introductionmentioning

confidence: 99%

DLC (H) coated 13Cr SMSS by high-pulsed power CVD technique

Zhang

Chen

Deng

et al. 2020

Hydrogenated diamond-like carbon (DLC: H) films were successfully fabricated on the surface of 13Cr super martensitic stainless steel by high-pulsed power chemical vapour deposition. The mechanical and tribological properties of the films related to the substrate bias voltages were investigated. The results showed that the surface hardness and tribological properties of the substrate after DLC film deposition were improved. The DLC films became dense, the grain size and roughness reduced, and the deposition rates increased as the bias voltage increased. In addition, the dense DLC films directly led to high nanohardness and elastic modulus. The H content decreased with an increase in the bias voltage, which may be the primary reason for nanohardness and modulus enhancement. Due to the relatively high H/ E* and H 2 /E* 3 ratios of films corresponded to high elastic strain and plastic deformation resistances reduced the wear loss, and the localized graphitization on the surface provided solid lubrication.