The Effect Of Friction On The Metal Cutting Essay

1813 Words 8 Pages
Friction is a crucial phenomenon in metal cutting which is very complex to model. It has a significant effect on the amount of power required for removing a given volume of metal, surface quality of the finished product, and the extent of tool wear. However, many studies assume no friction in the metal cutting process due to lack of experimental techniques to directly measure the coefficient of friction.
Sticking and sliding regions are the two contact regions along the tool-chip interface. A critical friction stress τ_c and coefficient of friction µ are assumed to exist in the sticking and sliding regions, respectively[42]. Most analyses have applied classical friction situation following Coulomb’s laws which is based on coefficient of friction [e.g., [55], [62]]. Frictional sliding force F is proportional to the force N normal to the interface at which sliding is taking place. This model can be expressed by:
However, the above equation fails to give accurate prediction in high normal stress conditions. Several studies applied modified Coulomb friction law [e.g., [42], [40], [63],[41]] in which critical friction stress depends on pressure normal to the tool-chip interface, coefficient of friction, and threshold value for the conventional Coulomb friction stress. In this model the contact point is in the sticking region and there is no relative motion between the chip and rake face of the cutting tool and shear stress parallel to the tool-chip interface is less than the…

Related Documents