从液态锡的电阻率研究其结构变化的滞后性  

Study on the Hysteresis of Melt Structure Variation from the Resistivity of Liquid Tin

作　　者：常芳娥[1] 李卫军[1] 吕士勇[1] 杨晓琴[1] 坚增运[1] 

机构地区：[1]西安工业大学材料与化工学院,西安710032

出　　处：《西安工业大学学报》2010年第2期155-159,共5页Journal of Xi’an Technological University

基　　金：国家自然科学基金(50571076;50671075);国家973项目(2006CB605202)

摘　　要：采用基于四电极法的电阻动态测量系统，对过热和过冷液态锡在加热、冷却和保温过程中电阻率的变化规律进行了动态测定．结果表明，液态锡的电阻率先随熔体快速加热后保温时间的延长而减小、随熔体快速冷却后保温时间的延长而增大，保温时间达到7～15分钟后趋于稳定．升温速度对液态锡的电阻率有明显影响，快速升温熔体的电阻率明显大于慢速升温熔体在同一温度下的电阻率．过冷液态锡的电阻率变化规律与温度高于熔点液态锡的相同．研究结果表明，液态金属的结构变化存在滞后性和传承性．温度变化后，液态金属的结构不能随温度同步达到其在对应温度下的平衡状态．By using a dynamic test system based on four-point probe method for measuring resistance, the resistivities of liquid tin superheated and undercooled during heating process, cooling process and holding process have been measured . It is found that the resistivity of liquid tin first decreases with increasing the holding time after a rapid heating process,and then increases after a rapid cooling process and tends towards stability when the holding time is 7 ~ 15 min. The heating rate influences the resistivity of liquid tin. At the same temperature, the resistivity of liquid tin heated at a higher heating rate is evidently larger than that at a lower heating rate. The resistivity-time curve of the undercooled liquid tin after changing the temperature is similar to that of the superheated liquid tin. From the results of resistivity in liquid tin, it can be deduced that the structure transformation of liquid metal exist hysteresis and inheritance. When a temperature change process has finished,the structure of liquid metal can not reach its equilibrium state in step with the temperature.

关 键 词：锡 电阻率 熔体结构 滞后性 四电极法 

分 类 号：TG111[金属学及工艺—物理冶金]