Pure Ni Raman spectroscopy wear map CNT-Ni Raman spectroscopy wear map In situ Chemical Diagnostic Tribology of Dry and Lubricated Thin Film-Based Technologies Thomas W. Scharf, Department of Materials Science and Engineering, The University of North Texas Auger electron spectroscopy map of unworn carbon nanotube (CNT) - Ni composite Pure Ni Raman spectroscopy wear map CNT-Ni Raman spectroscopy wear map Green=Ni and Red=C. 50 mm 50 mm 1200 1400 1600 1800 D' G Raman Shift (cm -1 ) Intensity (arb. units) 1604 D 1582 worn Ni-CNT 400 600 800 1000 NiO Intensity (arb. units) Raman Shift (cm -1 ) 553 unworn Ni-CNT CNT powder Raman determined wear-induced: Formation of an in situ, low interfacial shear strength graphitic film. Increased graphitization indicated by shift in G-peak, increased ID/IG and peak FWHM. 500 nm Mechanisms of solid and self-lubrication have been determined for Ni-CNT composites by in situ Raman spectroscopy spatial mapping worn surfaces to determine the formation of tribochemical products. The composites exhibit a self-lubricating behavior, forming an in situ, low interfacial shear strength tribochemcial graphitic film during sliding, resulting in a decrease in coefficient of friction (COF) compared to pure Ni.