3D finite element investigations on textured tools with different geometrical shapes for dry machining of titanium alloys

摘要

Effect of texture shapes and texture area density for machining applications is a potential topic of investigation. However, it is difficult to fabricate perfect dimensions by using available micromachining techniques. Finite element simulations can be an effective way to understand the effect of texture density, texture depth and different geometric shapes on machining performances. The present study deals with the 3D finite element investigations of different texture shapes to predict cutting forces during machining of titanium alloy under dry condition. Available Johnson-Cook material model parameters have been investigated to select suitable parameters for 3D finite element studies in titanium machining. Different geometrical shapes (circular, square, triangular and elliptical shape) with the constant area are modeled at the rake face of cutting tools to incorporate textures. The effects of texture shape are studied for variation in cutting forces with different texture area density and depth. The effect of texture shape is found to be less influential for dry cutting however area density is found to have the most dominant effect on cutting forces. Further, the linear regression model for tool-chip contact length has been developed for the textured and untextured tools under different machining parameters. The developed model has incorporated the chip serration effect (serration peak and valley heights) in the contact length model. The contact length model for the textured tool has been developed for the first time, and the contact length variation has been compared with the plain tools. The results reveal that textured tools have limited applicability for dry cutting of titanium alloys. Further, the associated mechanism of contact area reduction for textured tools has been found to be not applicable at increased feed and cutting speeds due to chip embedment into textured space.