Role of Cutting Fluids in Workpiece Temperature and Surface Error in Peripheral Milling
 
 

Ashish Gandhi | MS | 1999

Manufacturers are devoting increased attention to cutting fluids because of the environmental and health consequences associated with their use. Many recent studies have focused on these negative characteristics, but little attention has been directed at describing the effects of cutting fluids on machining process performance. The emphasis of this thesis is on quantifying the role that cutting fluid application has on workpiece temperature and surface error in a peripheral milling operation. A three dimensional model for heat transfer in the peripheral milling operation that can be used for both dry and wet cutting is established and verified experimentally. Measured temperatures were used in concert with an inverse heat transfer method to estimate heat source strengths for dry cutting and convection coefficients for wet cutting. The machining parameters that have a significant effect on the workpiece temperature are also determined using a normal probability plot.
 

Periodically varying milling forces and high cutting temperatures deform the flexible cutter (end mill) and the workpiece structures. Thus, in peripheral milling, as in any machining process, the actual amount of material removed at the location of the tool is always different from that desired due to the inherent flexibilities of the machining system. This difference between the actual wall thickness of a machined workpiece and the wall thickness that would result if the workpiece was perfectly rigid is defined as surface error. In this thesis, the surface error of clamped-clamped-clamped-free (C-C-C-F) A1-6061 workpieces, machined in the presence and in the absence of cutting fluids, is compared. The important machining parameters affecting the surface error are also determined using a normal probability plot.
 

For the peripheral milling operation, using straight flute end mills, a model has been developed to estimate workpiece temperature in the absence and presence of cutting fluid. Convection coefficients in the presence of cutting fluid have also been estimated. Finally, the workpiece surface error is compared for dry and wet cutting.
 
 

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