Thermo-mechanical coupling during belt grinding and corresponding surface integrity of titanium alloy

Belt grinding is a common surface machining method for titanium alloy parts. However, belt grinding can result in poor surface integrity when grinding forces or temperatures exceed a certain threshold. This study systematically studied belt grinding force and temperature under different parameters (i.e., belt speed, feed speed and normal displacement), and analyzed the surface integrity of titanium alloy under corresponding conditions, including three-dimensional surface morphology, surface roughness and grinding scratch morphology. As a result, it is revealed that the decrease of the belt speed, the increase of the feed speed and the normal displacement will lead to the increase of the grinding force, the decrease of the feed speed, the increase of the belt speed and normal displacement will cause the temperature to rise. Among many grinding parameters, the normal displacement has the most significant effect on the grinding thermal–mechanical coupling characteristics. High grinding force and grinding temperature will cause the surface quality to deteriorate and even more serious defects. As the grinding force increases, the surface roughness and the depth of grinding scratches show an increasing trend. When the normal grinding force reaches 21.4 N, the tangential grinding force reaches 12.6 N and the grinding temperature reaches 341.9℃, the surface roughness increases sharply, and the grinding burn will be formed on the workpiece surface. This research is of significance for better understanding the belt grinding mechanism and improving the surface integrity of titanium alloy.