Sn-Ag-Bi焊料熔体温度诱导液-液结构转变的研究  

Research on Temperature-induced Liquid-liquid Structure Transition of Sn-Ag-Bi Solders

作　　者：李小蕴[1,2] 吴炜[1] 祖方遒[2] 

机构地区：[1]合肥工业大学工业培训中心,安徽合肥230601 [2]合肥工业大学材料科学与工程学院,安徽合肥230009

出　　处：《金属功能材料》2011年第6期40-43,共4页Metallic Functional Materials

摘　　要：本文采用直流四电极法研究了Sn-3.5Ag-3.5Bi焊料熔体在连续两轮的升降温过程中电阻率随温度的变化关系,以此为基础进一步研究了该合金在650℃和800℃保温7h及随后的升温过程中电阻率的变化规律。结果表明,Sn-3.5Ag-3.5Bi合金中存在液-液结构转变,并且该结构转变在第一轮升温后是可逆的。结合保温及随后升温实验结果可知在第一轮升温过程中的结构转变是由不可逆和可逆两种不同类型的结构转变组成的。文章还从短程有序的角度分析了引起这两种转变的机制。In this paper,the temperature dependence of electrical resistivity of Sn-3.5Ag-3.5Bi;solder melts was measured at two heating and cooling cycles with the help of DC four-probe method.Based on it,further study was carried out on the resistivity of 650℃ 800℃ isothermal and subsequent heating experiments.The results show the liquid-liquid structure transition（LLST） does occur in Sn-3.5Ag-3.5Bi;melts,and the transition is reversible after the first heating process.Combined the results of isothermal and subsequent heating experiments,the LLST in first heating process is composed of irreversible and reversible types of structural changes.The transition mechanism is analyzed from the viewpoint of short-range orders（SROs）.

关 键 词：Sn-Ag-Bi焊料 液液结构转变 电阻率 

分 类 号：TG42[金属学及工艺—焊接]