Mg-Ni-Nd非晶合金晶化温度与晶化驱动力的预测

通过对Buschow提出的预测二元非晶态合金晶化温度的“最小空位”模型进行扩展，并进一步结合Miedema理论得到了一种预测三元非晶态合金晶化温度和晶化驱动力的理论方法.利用该方法计算了(Mg_70.6Ni_29.4)_1-xNd_{x(x＝5,10,15)非晶态合金的晶化温度、晶化驱动力以及晶化焓.其中晶化温度和晶化焓的理论预测值与实验值的相对误差分别小于8%和7%.同时发现较高的晶化驱动力会降低 关键词： 非晶态合金 晶化温度 晶化驱动力}

Prediction of the crystallization temperature and crystallization driving force for Mg-Ni-Nd amorphous alloys

A method for predicting the crystallization temperature and crystallization driving force of ternary amorphous alloys was provided. This method is an extension of the smallest-vacancy model suggested by Buschow for evaluating crystallization temperatures. The crystallization enthalpy and crystallization driving force are evaluated by using Miedema's semi-empirical model and the crystallization temperature is predicted. Calculation of the crystallization temperatures and enthalpy for (Mg_70.6Ni_29.4)_1-xNd_x(x＝5,10,15) amorphous alloys are performed by using this method. The calculated results accord well with experimental data and the relative error is less than 8% and 7% for crystallization temperature and crystallization enthalpy, respectively. It is found that with the increasing of crystallization driving force the retention rates of discharge capacity of Mg-Ni-Nd amorphous alloys decreases. For the (Mg_70.6Ni_29.4)_1-xNd_x(x＝1—20) amorphous alloys, the lowest crystallization driving force appears when the Nd content reaches 6.3%. That means (Mg_70.6Ni_29.4)_93.7Nd_6.3 amorphous alloy could have better retention rate of discharge capacity.