Evaluation on dry sliding wear behavior of (TiB+TiC)/Ti-6Al-4V matrix composite

Abstract

The dry sliding wear tests were performed for 10 vol.% (TiB+TiC)/Ti-6Al-4V matrix composites at various test conditions. The morphology and phases of worn surfaces and cross-sectional surfaces were investigated by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The wear loss of composites with the increase of load, but the wear behavior got more complex when the sliding speed and ambient temperature got higher. Low wear loss was achieved at lower sliding speed with higher temperature or higher sliding speed with lower temperature. A tribo-layer was always formed on worn surface during testing. It possessed different features and thus presented different effects during sliding wear. Meanwhile, the TiB and TiC particulates strengthened the Ti-6Al- 4V matrix, which increased the thermal stability of composites and postponed the occurrence of severe plastic deformation. In the mild wear region, those particulates could directly resist wear by reducing adhesive wear. In the steady stage, fractured TiB and TiC particulates participated in forming the tribo-layer together with wear debris, which effectively hindered the plastic deformation and thermal softening of the matrix. Experiment results suggest that the existence of different characteristic tribo-layers would result in the variation of wear behavior.