Mechanical and Thermal Stresses in Clamped, Brazed, and Bonded Carbide Tools

Abstract

A model based on the finite element method is presented for determining of thermal and mechanical stresses in a carbide insert due to heat and cutting forces induced during metal cutting with a brazed, clamped, and bonded carbide insert. Analysis revealed a high temperature gradient in the brazed insert, thus causing high thermal stresses. For the bonded insert a low temperature gradient but high temperatures were found, leading to possible tool edge chipping and a significant reduction of the bond layer strength. Finally local maxima of tensile and compressive stresses were identified on the rake face just after the chip had lost contact with the tool face. The estimated tensile stresses were close to the transverse rupture strength of sintered carbide. Shear stresses were at a maximum close to the tool edge at levels nearly equal to the shear flow strength of carbides. High compressive stresses can produce chipping at the tool tip.