【摘要】 系统地研究了 Zn-5% Al合金的快速凝固组织 .通过对合金激冷试样进行 X射线衍射、高分辨透射电镜、能谱分析试验 ,发现在 α相和 β相之间存在部分富 Al非晶相 ,在 DSC曲线上出现了一个明显的晶化放热峰 ,进一步证明非晶相的存在 .根据准化学理论和拐点分解机制提出一种新的液态金属分成波动模型 ,并利用此模型对非晶相产生的动力学过程及其稳定性进行了探讨 .更多还原

【Abstract】 The microstructure of a rapidly solidified Zn-5%Al alloy has been studied systematically. The quenched ribbons were examined by X-ray diffraction(XRD), high resolution transmission electron microscopy(HRTEM)and energy dispersive X ray spectra (EDXS). It was found that partial Al-rich amorphous phase exists between α phase and β phase, and further confirmed by an obvious exothermic peak for crystallization on the amorphous phase on the DSC curve. In order to explain these phenomena, a model of composition fluctuation of the liquid metal is put forward on the basis of the quasi-chemistry theory and the spinodal decomposition mechanism. The kinetic process of phase transformations discussed by means of this model.更多还原