In熔体的结构变化与粘度变化之间的联系

Correlation of the Change of Structure and Viscosity of In Melt

利用高温液态金属X射线衍射仪在280℃、390℃、550℃、650℃、750℃研究了In熔体的结构.实验结果表明,In熔体的平均最近邻原子间距和原子配位数随温度的升高而减小,原子团簇出现热收缩现象,且收缩在390～550℃温度区间内发生突变,收缩明显.利用回转振动粘度仪对In熔体在液相线以上不同温度进行了粘度测量,结果表明,随温度升高,In熔体的粘度降低,总体上呈现指数变化规律,在430℃和470℃附近出现异常变化.粘度出现异常变化的温度与其结构发生突变的区间一致,表明熔体粘度与熔体结构之间有着密切的联系.

The structure of In melt was studied at 280℃, 390℃, 550℃, 650℃, 750℃ respectively by using an elevated temperature Xray diffractometer. The experimental results show that the nearest interatomic distance r1 and the coordination number Ns of In melt decrease with increasing temperature from 280℃ to 750℃, and thermal contraction phenomenon of atom cluster occurs.A sudden change of structure and obvious contraction occurs in the range of 390550℃. The dynamic viscosity of In melt was measured in a wide temperature range above liquids by using a torsional oscillation viscometer. The experimental results show that the viscosity of In melt decreases with increasing temperature and meets the expotential correlation on the whole. The anomalous change of viscosity occurs at about 430℃and 470℃. The anomalous change temperature of viscosity is in accordance well with that of structure,suggesting that the viscosity has close relation to the structure of melt.