Development of an analytical model based on Mohr-Coulomb criterion for cutting of metallic glasses

摘要

The tension-compression asymmetry of metallic glasses has shown that the Mohr-Coulomb yield criterion can better determine the fracture characteristics of metallic glasses than the traditional Tresca and Von Mises criterion. Available cutting models based on the traditional yield criterion cannot describe the cutting mechanism of metallic glasses. An orthogonal cutting mechanics model of metallic glasses based on the Mohr-Coulomb yield criterion taking into account the influence of normal stress and temperature on shear plane is established. The analytical expressions for cutting force, shear angle and average temperature rise on shear plane are derived. Orthogonal turning experiments were designed and carried to validate the developed model. The analytically calculated cutting forces from the developed model considering cutting temperature rise were compared with the measured forces and the results show that a small difference of 7.7% was found, which is contrary to the prediction from traditional model based on von Mises yield criterion (nearly 60%) and the prediction from the model based on M-C without considering cutting temperature rise (more than 70%). The comprehensive comparison results show that the developed analytical model can accurately predict cutting process for metallic glasses. (C) 2016 Elsevier Ltd. All rights reserved.