Title: High performance nanostructured Cr-WS₂ solid lubricant coatings prepared on mechanically textured substrates

Authors: B. Deepthi; Praveen Kumar; G. Srinivas; Harish C. Barshilia

Addresses: Surface Engineering Division National Aerospace Laboratories Bangalore – 560 017, India ' Surface Engineering Division, Nanomaterials Research Lab, CSIR-National Aerospace Laboratories, HAL Airport Road, Kodihalli, Bangalore – 560 017, India ' Surface Engineering Division, Nanomaterials Research Lab, CSIR-National Aerospace Laboratories, HAL Airport Road, Kodihalli, Bangalore – 560 017, India ' Surface Engineering Division, Nanomaterials Research Lab, CSIR-National Aerospace Laboratories, HAL Airport Road, Kodihalli, Bangalore – 560 017, India

Abstract: Cr-WS₂ nanocomposite solid lubricant coatings were prepared on mechanically textured stainless steel substrates. Micron-sized dimples of approximately 10-12 µm depth and 100 × 80 µm² area with uniform dimple spacing of 300 µm were created on the substrates using a knurling tool. Substrate surface texturing improved the tribological properties of Cr-WS₂ nanocomposite coatings significantly. Cr-WS₂ nanocomposite coatings prepared on textured steel substrates exhibited a friction coefficient of 0.1 after 28,800 cycles compared to coatings prepared on non-textured substrates which exhibited a friction coefficient of 0.45. The dimpled regions acted as solid lubricant reservoirs and also helped in trapping wear debris. The retention of solid lubricant material in the dimpled region was confirmed using field emission scanning electron microscopy and energy dispersive X-ray spectroscopy studies.

Keywords: Cr-WS2 nanocomposites; chromium; tungsten disulphide; nanocomposite coatings; substrate surface texturing; tribological properties; solid lubricant reservoirs; nanotechnology; textured surfaces; friction coefficient; wear debris.

DOI: 10.1504/IJSURFSE.2015.072070

International Journal of Surface Science and Engineering, 2015 Vol.9 No.5, pp.466 - 478

Received: 03 May 2014
Accepted: 03 Oct 2014
Published online: 30 Sep 2015 *

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