Effect of the Formation of Tribo-Layer on the Wear Performance of TC4 Alloy

The wear performance of TC4 alloy was investigated under the load of 50~250 N at the ambient temperature of 200,400 and 600 ℃ by using MG-2000 type pin-on-disc high temperature wear tester. The morphologies, compositions and phase of worn surface and worn cross-section for the specimen were observed and analyzed by scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy. The results show that tribo-layers, which chemical composition was different from the matrix, were formed on the worn surfaces. The composition and distribution of tribo-layer had an important impact on wear performance of TC4 alloy. At 200 and 400 ℃, the tribo-layer with no or trace tribo-oxides distributed unevenly and was not protective. Wear rate increased with an increase of the temperature. At 600 ℃, the tribo-layer of tribo-oxides TiO₂ and TiO distributed uniformly and wear rate substantially decreased. Thus, the tribo-layer which was rich in tribo-oxides markedly improved the wear performance of TC4 alloy.