Exploring hard-rock cutting performances by a master–slave follow-up disc cutter

In this paper, a self-developed master–slave follow-up disc cutter is used to conduct rock-breaking tests on hard sandstone samples. Different working parameters were employed in the tests (e.g. cutting depth, cutting speed, cutting angle, and rotational speed) in order to explore their influences on cutting performance. The results indicate that the thrust, torque, vibration velocity, and roughness all increased continuously with increase of the propulsion speed and cutting depth. At the same time, the specific energy consumption was found to decrease continuously. As the rotational speed was increased, the thrust increased at first and then decreased. In contrast, the torque and roughness continuously decreased, and the specific energy consumption and vibration speed continuously increased. When the cutting angle was increased, the thrust remained unchanged. However, the torque, specific energy consumption, and vibration speed all decreased continuously, and the roughness increased continuously. The temperature of the surface of the cutting tool was found to be relatively uniformly distributed during the rock-breaking process; the highest temperatures generated were in the range of 200–300 °C. As the propulsion speed, cutting depth, and cutting angle were increased, the proportion of tensile fractures produced appeared to increase and the proportion of shear fractures decreased. As the rotational speed was increased, the proportion of tensile fractures decreased and the proportion of shear fractures increased. The results could provide useful information on the rock-breaking behavior involved and can be used to offer technical support for engineers using master–slave follow-up disc cutters in the field.