文摘
The surface integrity of a titanium workpiece is closely related to its surface quality and performance. In order to improve the surface integrity, low plasticity burnishing is adopted. In this study, the effects of burnishing pressure (5–20 Mpa), speed (50–600 mm/min) and feed rate (0.05–0.5 mm) on the surface integrity are studied by single factor experiments. Four aspects of the surface integrity are investigated, namely surface roughness, surface microhardness, surface residual stresses, and surface topography. The results show that increasing the burnishing pressure or number of passes can improve the surface microhardness and the residual stress. However, increasing the burnishing pressure or number of passes contributes to reducing the surface roughness. Increasing the feed rate also leads to an increase in the surface roughness. Decreasing the burnishing speed is beneficial for increasing the surface residual stress. The analysis results of power spectral density profiles reveal that the burnishing pressure and feed rate are the dominant factors on the surface topography of the burnished workpieces. The surface residual stress changes from −67.7 Mpa to −400.5 Mpa after the burnishing process. The surface roughness reaches the minimum value of 0.057 μm at the feed rate of 0.05 mm. There is nearly a 36 % increase in the surface microhardness as compared to that of the unburnished workpiece. It shows that low plasticity burnishing can efficiently improve the surface integrity of a titanium workpiece.
