Papers by Author: Jun Zhou

Abstract: In the present study, two-dimensional orthogonal slot milling experiments in conjunction with an analytical-based computer code are used to determine flow stress data as a function of the high strains, strain rates and temperatures encountered in metal cutting. By using this method, the flow stress of Al7050-T7451 is modeled. Through the comparison of cutting forces between FEM and experiment, the FEM model using predicted flow stress can give precise cutting forces. The work of this paper provides a useful method for material constitutive equation modeling without doing large number of cutting experiment or expensive SHPB tests.

Abstract: A burr formation process in micro-cutting of Al7075-T7451 was analyzed. Three stages of burr formation including steady-state cutting stage, pivoting stage, and burr formation stage are investigated. And the effects of uncut chip thickness, cutting speed and tool edge radius on the burr formation are studied. The simulation results show that the generation of negative shear zone is one of the prime reasons for burr formation. Uncut chip thickness has a significant effect on burr height; however, the cutting speed effect is minor. Unlike in conventional cutting, in micro-cutting the effect of tool edge radius on the burr geometry can no longer be neglected.

Abstract: In machining, the size effect is typically characterized by a non-linear increase in the specific cutting energy (or specific cutting force) as the uncut chip thickness is decreased. A finite element model of orthogonal micro-cutting was established to study the influence of tool edge radius on size effect when cutting 7050-T7451 aluminum alloy. Diamond cutting tool was used in the simulation. Specific cutting force and specific cutting energy are obtained through the simulation. The nonlinear scaling phenomenon is evident. The likely explanations for the size effect in small uncut chip thickness were discussed in this paper.