Microstructure and wear resistance of electrodeposited RE-Ni-Mo-P-B4C-PTFE composite coating

Abstract

The structure, hardness and wear resistance of RE-Ni-Mo-P-B4C-PTFE composite coating have been studied by means of X-ray diffraction, scanning electron microscopy, abrasion testing and microhardness testing. The results show that the structure of RE-Ni-Mo-P-B4C-PTFE composite coating experiences a transformation from amorphous via a mixture to crystalline as the heat treatment temperature is increased. Crystalline particles in the coating become gradually finer with the addition of B4C, B4C plus polytetrafluoroethylene (PTFE) and B4C plus PTFE plus rare earths (RE), in that order. The hardness and wear resistance of the RE-Ni-Mo-P-B4C-PTFE composite increase with increasing temperature, reaching peak values at 400°C and 300°C, respectively. The wear resistance of the composite coating is greatly superior to that of other traditional coatings.