仲钨酸铵对Ag-Sn合金粉末的氧化作用

EFFECT OF APT ON OXIDATION PROCESS OF Ag--Sn ALLOY POWDERS

本文采用氧化增重法(TGA),研究了添加少量仲钨酸铵(APT)对Ag-Sn合金粉末的氧化作用,用X射线衍射仪、电子探针和金相观察分析了粉末氧化前后相的转变、氧化物的分布、形貌。结果表明,Ag-Sn+APT混合粉末的氧化规律服从Wagner理论;APT的分解产物及形成的新相Ag_2WO_4作为活性氧原子源,促进Sn的氧化;添加剂APT在0～2.26wt-％成分范围内和相同温度、相同氧化时间条件下,氧化速率随添加量增加而加快;随氧化温度的提高,氧化速率加大,如在800℃下的氧化速率大于700℃下的氧化速率。

Oxidation processes of Ag-Sn alloy powders with a small quantity of additional APT were studied by gravimetric measurement (TGA). Microstructure, change of phase, distribution and morphology of oxide were analysed by X-ray diffractometer, scanning electron microscope and optical microscope. The results showed that oxidation process of the mixture agreed with Wagner's theory; dissociated pro- duction of APT and new phase Ag_2WO_4 formed in the oxidation were regarded as the sources of active oxygen atom, and enhanced the oxidation of Tin; when the temperature and time were the same, and in the component of 0～2. 26wt-%, oxidation ratio increased with the increase of APT.