On the stress field redistribution of tool–chip interface for micro-groove textured tools

The stress field redistribution at the tool–chip interface of micro-textured tools was examined. The effect of stress field redistribution on the cutting performance was also investigated, including cutting forces, friction characteristics, and chip morphology. The findings have shown that the main cutting forces were reduced by 18% through the decrease of average shear strength and tool–chip contact area. The equivalent average friction coefficient u_a deceased from 0.66 to 0.64 with the groove texture width increasing from 80 to 140 μm. The chip deformation coefficient also decreased from 3.4 to 2.77 with the increase of groove texture width, which was mainly attributed to the improvement of friction characteristics at the tool–chip interface. In order to characterize the stress field redistribution at the tool–chip interface, an improved theoretical model of stress field redistribution for micro-textured tool was proposed based on Zorev’s assumption. The stress field was assumed as zero in the groove texture zone and had a maximum local stress because of the appearance of derivative cutting. The proposed model was validated by the calculations of normal and friction forces. Combined with the theoretical calculations and experimental findings, the results have shown that with the increase of groove texture width, the decrease of normal and shear stress in the groove texture zone was enlarged. And the increase of normal and shear stress, caused by derivative cutting, was reduced. Then, under the combined effect of groove texture and derivative cutting, the friction characteristics at the tool–chip interface can also be improved. The present findings give more insight in to the stress field redistribution of micro-groove textured tools and the underlying friction mechanisms at tool–chip interface.