X線小角散乱法によるCu-4%Ti合金の低温時効初期過程の研究
1973 年 37 巻 1 号 p. 61-67
詳細
1973 年 37 巻 1 号 p. 61-67
The decomposition process of Cu-4% Ti alloy during the isothermal aging at relatively low temperatures, 200∼260°C, has been studied by means of X-ray small-angle scattering technique. From the analyses of the data of the integrated scattered intensity and the application of Porod’s law, it is suggested that spinodal decomposition takes place in the early stages of aging of this alloy and that sinusoidal composition fluctuations are produced in the alloy. The determination of the values of the amplification factor demonstrates that the kinetics of the decomposition is well in accord with Cahn’s theory of spinodal decomposition. At the later stages of the aging, the sinusoidal composition wave is considered to transform into a step-like one with well-defined interface between matrix and solute-enriched regions. The critical temperature, below which the alloy is allowed to decompose spinodally, is estimated to be about 350°C.
