论文部分内容阅读
粉煤灰经热碱液活化后,采用葡萄糖作还原剂,通过向碱性溶液中缓慢滴入Ag NO3溶液的方法制备了镀银复合粉体。采用扫描电镜、能谱仪和X射线衍射进行形貌观察及成分分析,并探讨了热处理对镀银复合粉体的影响。结果表明:热处理对镀银复合粉体的导电性和晶粒尺寸影响较大。随保温温度的升高,复合粉体的电阻率先减后增,而镀层的平均晶粒尺寸则一直在增大;随保温时间的延长,电阻率和晶粒尺寸都呈先减后增的趋势。适当的热处理能够消除镀层生长缺陷,改善复合粉体的导电性。镀银复合粉体在250℃保温40 min后电阻率达到0.011Ω·cm。
After activation of fly ash by hot lye, glucose was used as a reducing agent, and AgNO3 solution was slowly dripped into the alkaline solution to prepare a silver-coated composite powder. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to observe the morphology and composition analysis. The effect of heat treatment on silver-coated composite powders was also discussed. The results show that the heat treatment has a great influence on the conductivity and grain size of silver-coated composite powders. With the increase of holding temperature, the resistivity of composite powder decreases first and then increases, while the average grain size of the coating increases. With the increase of holding time, the resistivity and grain size decrease first and then increase . Proper heat treatment can eliminate the growth defects of the coating and improve the conductivity of the composite powder. The resistivity of the silver-plated composite powder reached 0.011 Ω · cm after being kept at 250 ℃ for 40 min.