Nano‐Twisted Double Helix Carbon Debris Improves the Wear Resistance of Ultra‐Thick Diamond‐Like Carbon Coatings. Issue 20 (26th August 2020)

• Record Type: Journal Article
• Authors: Sui, Xudong; Wang, Xinyu; Zhang, Shuaituo; Yan, Mingming; Li, Wensheng; Hao, Junying; Liu, Weimin
• Is Part Of: Advanced materials interfaces. Volume 7:Issue 20(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-08-26
• Subjects: diamond‐like carbon -- friction and wear -- nano‐twisted double helix -- wear debris; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202000857
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: Thick diamond‐like carbon (DLC) coatings with different silicon (Si) transition layer thickness are deposited by hollow cathode plasma immersion coating technology. The results show that the internal stress of the coating can be tuned by changing the deposition time of Si transition layer, thereby obtaining good adhesion strength. Friction and wear results show that all coatings have good tribological properties. The coating with 8 min Si transition layer (Si‐8) demonstrates the lowest friction coefficient (μ ≈ 0.03), even achieves ultralow friction (μ ≈ 0.008) for a short time. However, the wear rate of Si‐8 coating is found to be the largest (2.1 × 10 −16 m 3 (N m) −1 . The low friction coefficient of Si‐8 coating is related to its high degree of graphitization, complete transfer film and fine wear debris. In contrast, the Si‐16 coating has the lowest wear rate of about 5.6 × 10 −17 m 3 (N m) −1 with a relatively high friction coefficient (μ ≈ 0.1). This is due to its high hardness and the formation of a nano‐twisted double helix carbon debris during the friction process. This nano‐twisted double helix structure can consume additional plastic deformation energy, while reducing the interface contact area and increasing the interface bearing capacity, thereby improving the wear resistance of the thick DLC coating. Abstract : The unique nano‐twisted double helix carbon debris was first found during the rubbing process of the as‐deposited thick diamond‐like carbon (DLC) coating. HRTEM shows these debris have a composite nanostructure comprising a fullerene‐like structure and an amorphous carbon skeleton. The formation of this nano‐twisted double helix structure can improve the wear resistance of the thick DLC coating.