金屬引張り試驗中に於ける組織變化

Abstract

The structural change of metals during tension test was studied by the x-ray back reflection method. In this experiment, it was convenient to compare the gradual change in x-ray patterns with the applied energy which could be easily known from the stressstrain curve (Fig. 7).Up to the yield point, all the Laue-spots showed the lateral elongation caused by the small distortion of the crystal plane. The photographs (Fig. 5). were taken with the cylindrical camera. (Fig. 3) and examined by the microphotometer (Fig. 6). The writer suggested that these phenomena are suitable for the investigation of yield point of metals., For specimens which show large elongation, the Laue-spots method was applied in order to obtain a continuous spectrum line from deformed specimens, but was not applicable for the study of the greater distortion in the specimen. The radial diffuseness or the displacement of spectrum lines caused by the change in crystal lattice was found in this stage and continued till the specimens were broken down. Some photographs and their microphotometer curves were given in Fig. 9 and Fig. 10, and the change in lattice constants were given in Table 2. It will be noted that all lattice distortions showed, on the average, an expansion of them, and Aluminium is a single exception whose spectrum lines remain very fine at the break down point. Lastly the writer calcluated the increase of the latent energy accompanied by the la ttice distortion following the consideration of Wood, and Haworth. The former calculated the latent energy as a heat energy and the latter as an elastic. energy. In both cases we must know the distribution of lattice distortion in the specimens which will be given by the shape of the spectrum lines, but in rough estimation the writer obtained the mean distribution(Δd/d)av (Table 3) by the same assumption as Wood. The calculated values of the latent energy were given in the fourth and fifth columns of the Table 3 and the applied energy obtained from the stress-strain curves in the last column, The values of fourth column are too great and those of fifth column seem to be somewhat too small. It is expected to make a new consideration involving the above two.