SnO2表面改性对Ag/SnO2复合粉末烧结组织及性能的影响

采用沉积法和蒸发法分别对SnO2粉末进行WO3、Bi2O3 CuO表面改性处理,并用化学镀方法制备Ag/SnO2复合粉末.通过粉末冶金的方法对Ag/SnO2复合粉末进行烧结实验,并通过光学显微镜、扫描电镜观察烧结体的金相组织及复合粉末的形貌,对SnO2表面改性方法及添加剂种类对Ag/SnO2烧结性能和组织的影响进行了研究.结果表明:沉积法改性使烧结体组织中的SnO2分布更均匀,且能明显提高烧结体Ag/SnO2的致密度.Bi2O3 -CuO改性可消除SnO2的网络状分布,而WO3改性则显著改善电弧侵蚀后的表面组织.

Influences of Tin Oxide Surface Modification on the Morphology and Performance of Sintered Ag/SnO2 Composite Powders

Ag/SnO2 composite powders were prepared by electroless silver plating on SnO2 powders those were modified by the addition of WO3 and CuO+Bi2O3 and with the methods of precipitation and evaporation, respectively. The Ag/SnO2 composite powders were then sintered by the powder metallurgy process. The influences of modifying method and additive agent on the sintering behavior and morphology of Ag/SnO2 samples were investigated by means of optical microscopy and scanning electronic microscopy(SEM). The results indicated that the modifying method of precipitation is superior to evaporation on improving density and uniformity of SnO2 dispersion in the silver matrix. The net like distribution of SnO2 is improved by the combination of additives CuO and Bi2O3, while the surface morphology of AgSnO2 contact after arc erosion is obviously improved by the addition of WO3.