Low velocity impact wear behavior of MoS2/Pb nanocomposite coating under controlled kinetic energy

In this study, low velocity impact tests were performed to MoS2/Pb nanocomposite coating and its substrate (304 -stainless steel, for comparison). The machine is controlled based on kinetic energy and can achieve dynamic response during the tests. The MoS2/Pb coating exhibits better impact wear resistance, as shown by its favorable dynamic response. The energy absorption ratio evolution of MoS2/Pb coating indicates there were several impact damage forms during the tests, which was relevant to varied dominant impact damage mechanisms. In addition, tests with varied impact conditions were conducted, and distinct results were obtained, revealing the effects of tests parameters. Moreover, comparative analysis between values obtained from the Hertz theory and the measured revealed that the yield strength of MoS2/Pb coating was approximately 686.5 MPa, and the substrate was always under elastoplastic deformation although its impact kinetic energy was the lowest. The low velocity impact morphology was characterized by fatigue delamination because of the shearing stress in the subsurface. (C) 2017 Elsevier B.V. All rights reserved.