in Cutting Process

Abstract:The plastic deformation of materials obeys different laws under different strainrate loading conditions.In order to correctly understand the effect of strain rate on dynamic deformation，based on dislocation motion analysis，the viscous behavior of material deformation under different strain rate is deduced，the plastic deformation process from 102/s-105/s (and above) strainrate range is obtained through Hopkinson compression tests and metal cutting process experiments，the strainrate effect of 7075 aluminum alloy is studied，three parameters characterizing the strainrate effect are summarized，and the corresponding calculation method is proposed.It is found that the plastic deformation control mechanism of 7075 aluminum alloy will change from thermal activation to dislocation damping when the strain rate increases to a certain critical value (greater than 104/s and less than 1.5×104/s)，and according to the analysis of chip deformation in the cutting process，it is believed that insufficient time for material to fully deform and insufficient softening time are the main reasons for the strainrate effect.