抄録
The stacking disorder in the filed α2 phase af Cu–Al alloys was investigated by means of X-ray powder diffraction. The theoretical line profiles were calculated so as to reproduce the observed ones by using the diffraction theory of Kakinoki and Komura developed for one-dimensionally disordered structure. The values of the parameters in the diffraction equation, thus determined, indicate that the stacking mode in the filed α2 phase can be characterized by a statistical mixing of 3R, 9R in a negative sequence, and 2H. The annealing behavior of the filed α2 was examined and it was found that the filed α2 decomposes to (α+γ2), although the final stable state is the α2 phase. The annealing behavior observed is quite similar to that of the filed β1′ martensite of Cu–Al alloys.
