CALCULATION OF THE SPECIFIC CUTTING COEFFICIENTS AND GEOMETRICAL ASPECTS IN SCULPTURED SURFACE MACHINING

ABSTRACT

This article presents a method for obtaining the shear and ploughing specific cutting coefficients for a ball-end milling cutting force model. Thus, by using the proposed calculation method, the need for introducing variable shear cutting coefficients has been identified. This fact is due to the dependency among the specific cutting coefficients and the cutting edge inclination angle, which is variable in ball-end mills. Linear, quadratic and cubic polynomial shear cutting coefficients have been calculated, and the degree of adjustment obtained in each approach has been analyzed. At the same time, the expressions of the ploughing specific coefficients have been analyzed. The proposed calculation method has been applied to the following materials: a 7075-T6 aluminum alloy and a 52HRC AISI H13 tool steel. The results obtained from the validation demonstrate how the obtained coefficients are capable of predicting cutting forces over a wide range of cutting conditions. Finally, the results from applying the coefficients calculated in horizontal slot milling tests have been introduced in a model capable of calculating cutting forces in slope milling cases, which validates the calculation method proposed as a generic method for estimation of cutting coefficients.

Keywords:

• Complex Surfaces
• Cutting Force
• Specific Cutting Coefficient

ACKNOWLEDGMENTS

Thanks are addressed to Mr. E. Sasia and Mr. J. Muñoa for their help in the work. We thank the Spanish Ministry of Science and Technology for the financial support to this project, MICYT DPI2002-04167-C02-02, MCYT DPI2000-0075-P4, and Basque Government O/D-04-UN58.

Notes

Ball-end mill 30° helix angle, carbide K10 + TiAlN.