MICROSTRAIN CHARACTERIZATION OF METALS USING HIGH-RESOLUTION NEUTRON-DIFFRACTION

Two neutron diffraction arrangements were used for the investigation o f residual microstrains in metals. A high instrumental resolution was reached exploiting the neutron-optical properties of bent perfect Si c rystals, Delta d/d = 2.6 x 10(-3) for the three-axis arrangement and D elta d/d = 8 x 10(-4) in the case of energy-dispersive transmission di ffraction geometry. Low-carbon steel subjected to small tensile prestr ains was tested by using both instruments. Microstrain distribution wa s deduced from the width and shape of Bragg diffraction peaks and edge s, respectively.