X-ray diffraction method for measurement of elastic strain

A method is suggested, using diffraction line displacements, to facilitate simultaneous determination of one-dimensional strain in a particular direction in the surface of a polycrystalline material and of the lattice parameter corresponding to the unstressed state. A single exposure at perpendicular incidence of the primary X-ray beam enables both values to be obtained. Full advantage is taken of the ratios of diffraction ring diameters.