化学键参数和原子半径差与BMG合金的GFA关系

Research of the Relation Between Chemical Bonding Parameters and Difference in Atomic Size Ratios and GFA of BMG

综合大块金属玻璃 (BMG)的研究成果 ,用加权平均原则计算大块金属玻璃的原子半径差比率Δd、原子电负性差比率Δe以及离子率v三个物理参数 ,以大块金属玻璃的玻璃形成的临界冷却速度Rc 作为合金非晶形成能力 (GFA)的参数 ,用Origin软件分别对上述三个物理参量与Rc 的关系进行统计处理时发现 :Δd ,Δe ,及v与BMG的GFA的关系出现极小值现象 ,不同合金体系极小值的位置不同 ;玻璃形成能力强的合金体系 ,其各个组元的原子百分含量、组元原子之间的半径差以及电负性差三者之间的搭配是和谐的。金属玻璃合金的最优成分范围以及各种添加元素的最佳添加量现象可能与这三个物理参量与Rc 之间的极小值现象有关。

Three physical parameters such as the difference in atomic size ratios (Δd),the difference of atomic electronegativity ratios (Δe) and the ion ratio (v) were calculated by using the weighted average principle on the basis of the present BMG. The critical cooling velocity for forming glass (R_c) of the bulk metallic glass (BMG) was applied as the target parameter for the evaluation of the glass forming ability (GFA).The relation between the three related parameters and R_c was determined by using Origin,the results showed that a minimum was found in the relations between R_c and Δd,Δe and v,and for different alloy systems,the minimum positions were different one another. As for the BMG with higher GFA,the relations among atom percent,the difference of atomic size ratios and the difference of atomic electronegativity ratios between atom pairs were harmonious. The optimum compositional range of BMG and the optimum addition ratio of additive elements may be related to the minimum phenomena of the relation between three related parameters and R_c.