微动白层形成的控制因素及其对磨损过程的影响

在径向和复合(切向与径向复合)微动条件下，考察了2091铝锂合金在不同载荷水平和倾斜角度下的微动行为和损伤过程；结合不同阶段微动磨痕剖面分析，研究了微动白层(TTS)的形成条件，并详细分析了在不同微动阶段TTS的演变过程．结果表明，TTS形成的主要控制因素是表面切应力和切向位移，TTS形成过程呈现塑性变形特征；TTS对磨损过程具有重要影响．

Factors Controlling White Layer Initiation in Fretting and the Effect on Wear Process

The fretting and damage behavior of 2091 aluminum lithium alloy under radial and composite (tangential and radial) fretting against SAE-52100 steel at various loads and inclined angles were investigated in a ball-on-plate configuration. The cross-sectional morphologies of the fretted tracks of the Al-Li alloy at different stages were observed on an optical microscope, while the morphologies of the worn surfaces were observed on a scanning electron microscope, so as to determine the factors controlling the initiation of fretting white layer (i.e., the tribologically transformated structure, coded as TTS). Besides, the evolution of the TTS at different fretting stages was analyzed in detail. The results showed that no TTS was observed under radial fretting condition. The tangential stress and displacement of the contact surface were the factors controlling the initiation of TTS, which supported that the formation of TTS was characterized by plastic deformation. The TTS played a very important role in determining the fretting behavior of the Al-Li alloy/steel pair and exhibited different features in different stages of composite fretting.