Measurement of stress using synchrotron x-rays

Abstract

Stress analysis in polycrystalline materials reveals that stress can vary considerably amongdifferent subpopulations of grains. Samples of MgO and mixtures of MgO and spinel havebeen studied. After the onset of plastic flow, stronger grains or orientations will supportmore stress than the weaker grains. A grain to grain fabric develops that enables this stresspartitioning. The stress partitioning and the resulting fabric can invalidate staticmeasurements of elastic moduli. However, high temperature flow mechanisms reveal a moreisotropic strength behaviour resulting in a more uniform variation of stress withorientation.