"Cu-MoS2 composite coatings fabricated by cold spray and their tribological performances"

This present work is focused on the fabrication of copper-molybdenum disulphide (Cu-MoS₂) composite coatings using cold gas dynamic spray and their tribological behaviors. In order to obtain high quality coatings, measures carried out included modifications on spraying processing parameters (gas temperature, spraying distance, traverse speed), substrate temperature, morphologies of both Cu and MoS₂ powders, as well as the way feeding powders to the gun. The most promising changes were preheating the substrate and feeding the powders separately from two hoppers. Dry sliding wear tests were then performed on selected coatings. We used a custom-built in-situ tribometer to observe directly the formation and flow of “third bodies”—materials generated from the parent materials during wear process. Post-analysis by scanning electron microscopy (SEM) and Raman spectroscopy showed morphology and chemical compositions of wear tracks. Electron Channeling Contrast Imaging (ECCI) on wear track cross sections helped to reveal sliding-induced microstructures.