Material machining-induced near-surface residual stress states: An X-ray diffraction and electron-microscopy study on a tungsten plate

Abstract

In the present work band sawing, electrical discharge machining, cutting by means of cut-off wheel, grinding, turning and water jet machining were examined by X-ray diffraction with regard to the development of residual stresses in the machining zone. The deformation zone could be resolved by electron microscopy and electron backscatter diffraction. In all mechanical processes, shear forces occur perpendicular to the direction of the cut. These in turn are reflected in the occurrence and magnitude of the individual stress tensor components. All mechanical processes lead to compressive principal stresses. The stress states are triaxial in nature. The shear stress components are particularly pronounced when cutting with the cutting wheel, followed by grinding and band sawing. Wire electro-discharge machining proves to be a special case.