中性子回折による銅と銅合金の引張変形中の集合組織その場観察

抄録

Copper and copper alloys exhibit wide varieties of deformation textures depending on the chemical compositions and production process. Precise analysis and modeling of texture evolutions are important for developing the various copper alloys efficiently. In this study, we conducted in–situ neutron diffraction experiments during tensile tests of pure Cu and Cu–Mg alloy at iMATERIA beamline in J–PARC (Japan Proton Accelerator Research Complex). Texture evolutions of the copper alloys were evaluated by a time–of–flight neutron diffraction method. Neutron shielding sheets were used to mask areas of the tensile specimens to maintain a constant volume section for analyses. These careful measurements revealed that increasing rate of <111> component during tensile deformation of pure copper was higher than that of Cu–Mg alloy in larger strain region (above 0.22 in true strain), whereas the increasing rates of pure copper and Cu–Mg alloy were similar in smaller strain region (below 0.22 in true strain). We also conducted the crystal plasticity finite element calculation of tensile behaviors of the copper alloys. The initial crystal orientations that well reproduced initial textures of in–situ experiments were used for the calculation. Same material parameters of crystal plasticity were used for pure copper and Cu–Mg alloy. Texture evolutions of calculation results qualitatively agreed with experimental results. Under the present calculation condition, the increasing rate of <111> component of Cu–Mg alloy was higher than that of pure copper as opposed to the experiments.