【摘要】 研究了电磁场作用下Al Mg扩散偶的界面结构组成和界面中间相的成长规律。结果表明 ,电磁场作用下Al Mg扩散偶界面中间相 (γ相和β相 )的厚度增加 ,并且界面中间层的厚度随电磁场强度和频率的增加而增加。电磁场作用下界面中间相的成长符合抛物线长大规律。计算了非电磁场与电磁场作用下Al Mg扩散偶界面中间相 (γ相和β相 )的成长常数和激活能 ,电磁场增加了扩散偶界面中间相的成长常数 ,提高了原子扩散过程中原子的跃迁频率及激活熵 ,提高了扩散过程中原子的自由度 ,加快了原子的扩散过程 ,从而加速了中间相的长大速度 ,使中间相的厚度增加更多还原

【Abstract】 The influence of an alternative magnetic field on the structure and growth of the intermediate phase in Al Mg diffusion couple was studied. The experimental results show that electromagnetic field increases the thickness of the intermediate phase, namely β and γ phase, and the effects increase with the intensity and frequency of the electromagnetic field. The parabolic rate law is obeyed in the growth of the layer β and γ phases in the Al Mg diffusion couple. The frequency factor( k 0) and the activation energy for intermediate phases growth with and without electromagnetic field were calculated. The influence of the electromagnetic field is mainly on the pre exponential frequency factor and not on the activation energy for the process. It suggests that the effect of the electromagnetic field is to increase the frequency of the atoms involved in the thermally activated process and/or the activation entropy rather than the barrier height. Entropy will increase if the AC magnetic field increases the degrees of freedom at the saddle position in the thermally activated event. As a result, the diffusion process of atoms is promoted and the growth rate of the intermediate phases is increased.更多还原