Evolution of tribolayer in GH2132/GH4169 fretting wear at elevated temperatures

To investigate the development of the tribolayer in the GH2132/GH4169 superalloy pair, a systematic tangential fretting wear interruption test was conducted to analyze the microstructure, chemical composition, formation mechanism, and evolutionary characteristics of the tribolayer at 600℃. The results reveal that in the early stages of fretting, severe plastic deformation of material in the contact area and dislocation accumulation within the grains promote dynamic recrystallization and crack initiation, ultimately resulting in significant adhesive wear. As the test progresses, tribo-sintering of oxidized debris and continuous grain refinement give rise to a dense nanocrystalline tribolayer with enhanced hardness. This tribolayer, which is composed of nanocrystalline metal oxides, unoxidized nanograins, and amorphous phases, forms at the contact interface and serves as a mechanically and chemically robust barrier. It suppresses metal-to-metal contact, slows oxidation, and significantly reduces the wear rate, thereby stabilizing the worn surface.