Nanotribology studies of Cr, Cr2N and CrN thin films using constant and ramped load nanoscratch techniques

The nanotribological behavior of DC magnetron sputtered Cr, Cr2N and CrN th in films has been studied using nanoscratch techniques. Constant and ramped load (5 mN) scratches were made using a Nano Indenter II system on 500-nm- thick Cr, Cr2N and CrN thin films. Ramped-load scratch studies have been ca rried out an 10-nm-thick Cr, Cr2N and CrN. Wear tracks were imaged by atomi c force microscopy. The dependence of the displacement, residual wear depth , percent elastic recovery, and friction coefficient on load is compared in constant load and ramped load tests. Under the same (maximum) load, consta nt load tests exhibit higher displacements, residual depths and friction co efficients, but lower percent elastic recoveries. The chromium nitride film s (Cr2N and CrN) show less permanent damage, lower coefficients of friction and higher percent elastic recovery than pure chromium under the same (max imum) load. However, the adhesive strength of Cr2N needs to be improved. (C ) 2001 Elsevier Science B.V. All rights reserved.