Effect of sample geometry on texture measurement of metallic materials using angle dispersive neutron diffraction

角度分散型中性子回折による金属試料の集合組織測定に及ぼす試料形状の影響

徐 平光   ; 山本 和喜 ; 岩本 ちひろ*; 高村 正人*

Xu, P. G.; Yamamoto, Kazuyoshi; Iwamoto, Chihiro*; Takamura, Masato*

While the bulk crystallographic textures are usually evaluated through the relative difference in neutron diffraction intensities of polycrystal materials from various sample orientations, an irregular sample geometric shape (different from a sphere and a cube) has an evident effect on the stereographic orientation distribution of neutron diffraction intensities due to the change in locally diffracted gauge volume and the neutron penetration path, which disturbs the quantitative calculation of real preferred orientation of materials and leads to clear uncertainty in nondestructive bulk texture measurements of finished or semi-finished products. Here, the stereographic diffraction intensity distributions of several high strength low alloy steel samples with same microstructure and texture but in various shapes and sizes were measured using RESA angle dispersive neutron diffraction. By referring to the classic neutron attenuation correction theory, the absorption correction reliability was examined to enable that the relevant intensity ratios among the rolling direction, the normal direction, the transverse direction, etc. are almost consistent with the corresponding data from a referred cubic sample. In the poster session, the recalculated bulk textures using the intensity-corrected diffraction profiles of different shaped samples will be given out to make a further comparison and discussion.