Cu-4Ti合金调幅分解的TEM研究

A TEM Investigation of Spinodal Decomposition in Cu-4Ti Alloy

通过透射电子显微镜对Ｃｕ－４Ｔｉ合金的调幅分解过程进行了研究。确认调幅分解是Ｃｕ－Ｔｉ合金相变初期的过程之一。现有的淬火速度（盐水冷却）不能抑制调幅分解的发生，淬火态调幅波长约为５．７ｎｍ。研究表明，调幅分解与调幅组织的长大是两个完全不同的过程，分别属于连续相变和非连续相变。这两个过程的波长长大动力学分别符合λ［３］－λ［３］－＝Ｋｔ定律，长大激活能分别为１７６ｋＪ／ｍｏｌ和１３４ｋＪ／ｍｏｌ。

Spinodal decomposition in Cu-4Ti has been studied by transmission electron microscope (TEM) It is indicated that spinodal decomposition, which is not supressed by rapid quenching (brine cooling), is an elementary phase transformation process in Cu-Ti alloys The wavelength of the modulated as-quenched structure is approximately 5 7nm A new idea for the development of the modulated structure has been offered, that is, it takes place in the two stages: spinodal decomposition and growth of the modulated structure The law λ 3-λ 3 0= Kt holds for two stages The growing activation energy of mean modulation wavelength for the above stated two stages are 176 kJ/mol and 134 kJ/mol, respectively