Investigation on specific milling energy and energy efficiency in high-speed milling based on energy flow theory

Manufacturing energy consumption affects both the environment and manufacturing costs. Therefore, evaluating the energy consumption of the metal cutting processes is required. Accordingly, the idle power and total power were separately measured with a multimeter. A mechanical milling force model was constructed and validated by high-speed milling experiments with the dynamometer. The specific milling force coefficients (with respect to different cutting parameters) were obtained through high-speed milling experiments and a mechanical milling force model. The specific milling coefficients show size effect, with the feed per tooth, axial milling depth and radial milling width decreasing owing to the size effect of the specific cutting force. A general mechanical milling power model considering the size effect was established and validated by the milling power measurements in the milling experiments. The specific milling energy shows the same trend as the specific milling energy coefficients. The specific removing energy increases with rotation speed, feed rate per tooth, axial cutting depth and cutting width decreasing, owing to the idle energy of spindle. The energy efficiency increases as the milling parameters increase, owing to the larger material removal rate (MRR) and the reduced consumption of idle power in specific removing volume. A larger feed per tooth is recommended in high-speed milling, owing to the higher energy efficiency and marginal utility.