High Performance Nanostructured Cr-Ws2 Solid Lubricant Coatings Prepared On Mechanically Textured Substrates

Cr-WS2 nanocomposite solid lubricant coatings were prepared on mechanically textured stainless steel substrates. Micron-sized dimples of approximately 10-12 mu m depth and 100 x 80 mu m(2) area with uniform dimple spacing of 300 mu m 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.