抄録
Regarding the quenching effects of ordinary chill-cast specimens of the copper-rich Be-Cu alloys the author had previously been investigated and reported(1). In the present research, the same effect has been observed by the microscopic, röntgengraphic and dilatometric methods, with regard to the variations of those effects due to the differences of the crystallized directions of the specimens.
The alloys containing 2.2%_??_4.4% of Be were cast into the mould, as shown in Fig. 2., designed to ensure the special mode of crystallization, and from the ingot thus obtained, two kinds of specimens, i.e. (B); the normally crystallized, and (A); the uni-directionally crystallized, were taken. Now, these two kinds of cast specimens were respectively normalized and quenched, and then the dilatometric changes during heating were differentially measured. As the results of these experiments, it was found that the quenched specimens indicate the most remarkable variations of changes, according to the direction of crystallization; For instance, vigorous expansion was observed as the quenching effect of the specimen (A), while, a servere contraction was found in the case of the specimen (B), though its composition is the same as (A).
It was elucidated that the cause of those variations of the dilatometric changes in both kinds of specimens, may be considered to rest on the difference of the orientation of α- and β-crystallites.
Moreover, the similar studies were repeated in connection with the rolled specimens of the same alloys.
