Abstract
The appearance of the striated structure of copper-aluminium light alloys was investigated in the case of various heat-treatment. The reseaches also on the effects of cold-working and content of copper were thoroughly carried out. The results obtained maybe summarized as follows: - (1) The structures of the alloys quenched at about 0°, are most remarkablly striated, even in the case directly after quenching as well as tempering. When ever the temperature of the quenching medium be higher or lower than the above case, the striation weakens and at last disappears. It is carefully to be watched that the greater the quenching effect is, the more the striation of the structure increases. (2) The hardness increases slightly followed by the appearance of the striated structure. (3) No effect of cold-working upon the striation of the structure is observed. (4) The striated structure begins to appear in the alloys containing over ca. 1.5% copper, and the more the content of copper increases, the more the striation, of the structure intensifies. Lastly X-rays analyses were carried out on the single crystals of the specimens containing 3.85% copper. From these results together with above-mentioned ones, we arrive at a conclusion that the striated structure appears as the result of the slipping along the plane parallel to the {III} face, owing to the quenching stress. Futhermore, the author confirmed in the present research that both Gayler's and Wassermann's theories, with regard to the formation of the striated structure, were not to be proper.
