Abstract. In this work 3D visualization of wear in milling inserts has been investigated by Focused
Ion Beam tomography. It has been observed that the morphology of the cracks differs in the z-axis
direction, allowing particular characteristics of the microstructure and wear evolution to be visible.
Two types of cracks develop: principal and lateral cracks. The formation of lateral cracks is strongly influenced by the degradation of the binder phase in the regions surrounding the principal crack. The lateral cracks and the deflection of the main cracks present a particular semi-elliptical geometry, which correlates with the stress field originated during the input of a cycling load in a fatigue condition
