Impact wear behavior of WC/a-C nanomultilayers

Abstract

Abstract A novel design of WC/a-C multilayers with ultrathin modulation period ranging from 1.3 to 11.5 nm was fabricated by unbalanced magnetron sputtering process, and the influence of modulation period on the impact wear behavior of the films was investigated from impact dynamic response and typical wear analysis. Results show that the peak impact force, impact energy absorption rate and impact wear volume loss of the films decrease firstly and then increase with increasing the modulation period, and both reach the minimum value at Λ = 9.1 nm. High hardness, toughness and plastic deformation resistance originated from the ‘superlattice-like structure’ of the films at appropriate modulation period are proved to be responsible for the low peak impact force, low impact energy absorption rate and then the improved impact wear resistance. While, the films with low hardness and H3/E2 have severe plastic deformation and impact-induced graphitization during impact process which in turn further reduce the hardness and H3/E2 of the film itself, thus eventually resulting in severe impact wear.