Abstract: The irrationality of an existing heating resistance model is analyzed firstly. In view of the deformation characteristic of shear zone, a new heating resistance model coinciding with the real deformation state of shear zone is proposed. The relationship among the three components of this resistance and tool angle, cutting condition, deformation coefficient are studied theoretically and theoretic formula of heating resistance is obtained. Secondly, an accurate measurement method for this resistance is put forward according to the characteristic of heating circuit. The experiment results show that this resistance will decrease when cutting depth or feed is increased, while it will increase when cutting speed is increased, which are consistent with the theoretical analysis. An experiential formula for this resistance and the three factors of cutting condition is also obtained. Thirdly, it is pointed out that the variation of cutting condition can be detected by the variation of heating resistance, so heating current can be adjusted automatically according to the variation of this resistance. Finally, it is indicated that for the three components of heating resistance, the material resistance and spread resistance will improve the machining performance of workpiece material, while tool-chip touch resistance will aggravate the wear of rake face.

Key words: Electric hot machining, Heating resistance, Model, Resistance measurement, Tool wear