【作者】 刘想梅；

【导师】 郑冀；

【作者基本信息】 天津大学 ， 材料学， 2004， 硕士

【摘要】 摘要 本文采用溶胶－凝胶法制备纳米掺杂氧化物的 ＳｎO２粉末，并通过掺杂、包覆等工艺改善 ＳｎO２的导电性及 ＳｎO２和银的浸润性，得到的 AgSnO2 触头材料的具有低的接触电阻，较好的物理性能和热性能。　 实验过程中运用TEM 表征了溶胶-凝胶法制备的纳米掺杂氧化物ＳｎO２胶粒，采用 XRD 和 DTA-TG 方法对掺杂 ＳｎO２进行了分析；应用阿基米德法测量烧结后的掺杂 ＳｎO２试样密度，并通过桥式电阻仪测量其电导率；运用 XRD 分析了SnO2-TiO2 包覆粉的成分和晶粒度，SEM 及 EDS 表征了 Ag 在 SnO2-TiO2 粒子上的沉积状况；最后对获得的 Ag(SnO2-TiO2)电接触材料的电导度，硬度，密度等物理性能进行了测试，运用 DTA-TG 方法分析其热性能。 研究结果表明：采用溶胶-凝胶法制备纳米掺杂的 SnO2 凝胶（掺杂物分别为TiO2、ZnO、Sb2O3、CuO），得到的纳米掺杂氧化物-SnO2 凝胶胶粒尺寸为 50nm左右。DTA-TG 分析确定了纳米掺杂氧化物-SnO2 的热处理区间，XRD 分析进一步确定了最佳热处理温度为 500℃；掺杂离子与 SnO2 形成了置换固溶体；烧结后的纳米掺杂 SnO2 粒子的物理性能分析可知 Ti离子为最佳的掺杂物。包覆后的SnO2-TiO2 粉末能够在 Ag 基体上均匀分布，且增加了 Ag 与 SnO2-TiO2 之间的润湿性和结合强度。 Ag(SnO2-TiO2)触头材料的物理性能和热性能分析表明包覆制粉工艺提高了材料的力学和物理性能；最佳混粉时间为 30 分钟，最佳包覆工艺为后加水合肼进行还原。且制备 Ag(SnO2-TiO2)触头材料的性能超过国标，具有良好的应用前景。更多还原

【Abstract】 ABSTRACT Sol-gel method is used to prepared SnO2 powder nano-doped with oxidates andthe electrical conductivity of SnO2 and infiltration between oxidates and silver areimproved by coating process, through which AgSnO2 contact materials have lowcontact resistance, good physical and thermalperformances. SnO2 nano-doped with oxidates is analyzed by TEM. The relationship betweennano-doped SnO2 gel and temperature is obtained using DTA-TG and XRD. Thedopant with excellent physical performances is obtained through analysis of physicalperformances of samples such as density and electrical conductivity. The chemicalcompositions and grain size of cladded SnO2-TiO2 powder are analyzed using XRD.Using SEM and EDS investigate the deposition of silver on SnO2-TiO2 particles. Thephysical performances of Ag (SnO2-TiO2) contact materials, such as electricalconductivity, hardness and density are measured and their thermal performance isanalyzed using DTA-TG. The results are shown as follows: SnO2 nano-doped with oxidates (TiO2、ZnO、Sb2O3、CuO) can be prepared by sol-gel method, whose size is about 50nm; theanalysis of DTA-TG and XRD shows that the optimal temperature is 500℃ and thatsubstitution solid solution is formed between SnO2 and dopant ions. The analysis ofphysical performances of sintered nano-doped SnO2 particles indicates that Ti is theoptimal dopant ion. Coated SnO2-TiO2 powder can be distributed homogenously onsilver substrate, which strengthen the bonding strength and infiltration betweenSnO2-TiO2 and silver. The thermal and physical analysis shows that mech-physicaland thermal performances of Ag(SnO2-TiO2) contact materials are improved throughpowder coating process. The optimal coating process is: mixing for 30 minutes;adding hydrazine hydrate lately.更多还原