Papers by Author: Y.M. Rong

Abstract: This paper presented a finite element simulation model for the analysis of AISI D2 orthogonal cutting process using TiAlN coated inserts. Firstly, AISI D2 material constitutive model was built based on power law model, which was used in the FEM codes to describe the effect of strain, strain rate and temperature on the material flow stress. In modeling the chip formation, a damage model was employed to predict the chip separation. Then cutting edge radius and thickness of TiAlN coating of cutting tool were measured by SEM. Friction coefficients of cutting tool against AISI D2 steel were obtained by ball-on-plate friction tests on UMT-2 high speed tribometer. Finally, finite element simulations of AISI D2 orthogonal cutting processes were performed using AdvantedgeTM software. The simulated results of cutting forces and chip morphology showed good agreement with the experimental results, which validated the reliability of the cutting process simulation method.

Abstract: In this study, mechanical model of plowing process considering material flow process was built. Dynamic material model of workpiece (AISI D2) was included in this plowing model. The friction between diamond indenter against AISI D2 steel was obtained by the ball-on-plate test. The scratch tests with diamond indenter against AISI D2 steel were performed. The scratch morphology was investigated by white light interferometer. The scratch forces in the different loads were calculated by the mechanical model of plowing process. The calculated scratch forces showed good agreement with experimental results.

Abstract: Grain-workpiece interface, which resembles a micro-cutting process, directly modifies the workpiece surface and dominates all the output measures of a grinding process. The abrasive grains always become worn or dulled during grinding, which alters the grain-workpiece interface output and turns to be the primary factor that causes the transient or time dependent behavior in monolayer superabrasive grinding. Therefore, the study on how the grain wear influences the grain-workpiece interaction through micro-cutting analysis becomes necessary. As the emergence of the packaged FEM software for micro-cutting simulation, apart from single grit cutting test, it enables another qualitative and quantitative investigation method on grain-workpiece interface mechanism in an efficiency and effective manner. Based on previous efficacy verification of Third Wave AdvantEdge^TM, the FEM simulation is carried out to investigate the effect of grain wear on its micro-cutting performance. The simulation results provide an illustrative manner to interpret the phenomenon and mechanism, and the results can be used in the grinding process modeling in the future as well.

Abstract: The microstructure evolution of ground subsurface in AISI D2 steel surface grinding was investigated in this study. The effect of grinding parameters and grain size of wheels on white layer formation was presented. The surface integrity parameters of microstructure and microhardness were measured and analyzed. It was found that the white layer and dark layer may occur more easily when using finer grain size of wheel and white layer and dark layer may occur with the increase of grinding parameters, such as wheel rotation speed, workpiece speed and depth of cut.