Role of Forming In Micro‐ And Nano‐Scale Material Removal Mechanisms During Surface Machining of Ductile Materials
The material detachment mechanisms of ductile metal surfaces are studied experimentally during dry grinding operation in a simulated experiment with near single grit contact with the surface. The spectra of the cutting and thrust forces are recorded and analyzed. It is found that the thrust force changes its direction from a compressive to a tensile mode. The ratio between the thrust and cutting force is consistently found to be greater than 1. In the grinding process, the chip is found to be much shorter and thicker than those predicted by traditional continuum cutting theories. From the analysis of chip dimensions and cutting forces, we speculate that the cutting process during a grinding operation comprises of three phases as follows: (i) lifting up of the surface ahead of the abrasive particle, (ii) segmentation through shear instability, and finally (iii) chip tearing from the surface. Accordingly, the heating cycle is much longer with a lower mean temperature, compared to those of macro machining. In addition, the proposed deformation field leads to loss of constraints ahead of the cutting grits, and possibly reducing the thrust to cutting force ratio. This suggests that forming took place prior to material detachment in grinding.
The following article appeared in AIP Conference Proceedings 712 (2004): 123, and may be found at doi: 10.1063/1.1766511.