Research On Failure Mechanism And Control Technology Of Fretting Fatigue

Fretting fatigue occurs at the contact surface between two components, where relative micro-slip at the interface between two surfaces in intimate contact plays an important role. Fretting fatigue is one of the most important phenomena for inducing a dramatic reduction of fatigue strength and consequently, of unexpected failure accidents. In this paper, the failure mechanism and control technology of fretting fatigue have been studied by means of fatigue testing and finite element analysis. The research work in this paper can be concluded as follows:The surface and cross-section topography of worn zones, and the abrasive dust layer are investigated by means of fatigue testing, metallography, EDX and scanning electronic microscope analysis. The change of the failure mode during the test process and the failure mechanism are studied.The effects of laser beam quenching (LBQ) on the tribological characters, microstructure, and failure topography are experimentally studied. The LBQ refines the crystals of TC4 titanium alloy and greatly reduces the fretting wear. The LBQ also makes some of the a phase change into phase, and the multiplayer structure is obtained.Finite element model is set up according the geometric shape, contact condition, and boundary condition. Analysis is conducted with this model. With this finite element model, the exact contact stress during the fretting fatigue procedure can be got by calculation, which greatly simplified the research work, and the effect of varied friction coefficient can be easily recognized instead of experiment.Based on the experiment research and finite element analysis, the procedure of fretting fatigue failure and the failure mechanism are made clear in this paper. The results obtained in this paper will do much help for further fretting fatigue study and the choice of fretting fatigue control technology.