Chipping and Breakage of Carbide Tools

Abstract

<p>The purpose of this project was to study the failure mechanisms of carbide tools in turning operations due to fracture of the cutting edge. The study consisted of a combination of turning tests, examination of fracture surfaces and an analysis of the stresses in the tool as produced by the cutting force. Thermal stresses are so far not considered. It is concluded that chipping is a ductile failure due to high shear stresses at the cutting edge and breakage is brittle fracture originating at the rake face at a local maximum of tensile stress.</p> <p>For the finite element stress analysis a new method of successively refining mesh while diminishing the analysed area is introduced which is rather effective and economical in that all computation except for the final field is done only once for various loading cases.</p>