Microstructure, chemical states, and mechanical properties of V–C–Co coatings prepared by non-reactive magnetron sputtering

• Published in: Thin solid films 2013-07, Vol.540, p.135-141
• Main Authors: Zhang, Xiaojuan, Wang, Bo, Zhan, Zhaolin, Huang, Feng
• Format: Article
• Language: English
• Subjects: Charge transfer; Coatings; Columns (structural); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Exact sciences and technology; Hardness; Magnetron co-sputtering; Magnetron sputtering; Materials science; Mechanical and acoustical properties; Mechanical properties; Methods of deposition of films and coatings; film growth and epitaxy; Microstructure; Nanocomposite; Nanoindentation; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Other topics in nanoscale materials and structures; Physical properties of thin films, nonelectronic; Physics; Strong Co/VC interface; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Toughness; V–C–Co coating
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.06.027

V–C–Co coatings have been prepared by non-reactive magnetron co-sputtering from VC and Co targets. The microstructure, chemical states, and mechanical properties are examined as a function of Co content in the coatings. The coatings are dense, with columnar growth structures. High resolution transmission electron microscopy (HRTEM) studies identify a nanocomposite microstructure for the 12.4at.% Co coating, in which ligament-like Co-rich regions partially separate the nanocrystalline VC grains. X-ray photoelectron spectroscopy studies reveal a noticeable charge transfer from Co 2p states to C 1s states. This charge transfer, in addition to the ligament-like Co-rich regions as revealed by HRTEM, points to the formation of a strong Co/VC interface. The nanoindentation hardness of the coatings drops steadily with the Co content, from 29GPa for pure VC to ~21GPa for the 12.4at.% Co coating. Meanwhile, the plasticity characteristic increased from 0.42 to 0.53. •Nanocomposite V–C–Co coatings with strong Co/VC interfaces were formed.•Found nanocrystalline VC grains separated by ~1nm thin Co-rich ligaments.•A noticeable amount of CCo bonds between VC and Co is identified.•V–C–Co coatings exhibited a higher plasticity characteristic than VC.