不同还原剂对镀银铝粉的微观结构与性能影响

Effects of different reducing agents on the microstrcture and properties of Ag/Al powder

为提高镀银铝粉镀液中银离子利用率,通过改进还原剂体系的方法,采用化学镀工艺,以甲醛、葡萄糖+酒石酸、葡萄糖为不同还原剂制备镀银铝粉。用X射线衍射仪、场发射扫描电镜及粒度分析仪等表征了镀银粉体的微观结构,使用矢量网格分析仪测试其电磁屏蔽性能。结果表明:用葡萄糖+酒石酸复合还原剂作为制备镀银铝粉的还原剂,其银包覆性最好,且银层无脱落,优于其他2种还原剂。压实电阻率低至11.3 mΩ·cm,镀银铝粉振实密度值为1.651 g/cm^(3),松装密度为1.352 g/cm^(3),频率8.2~12 GHz范围内的平均电磁屏蔽效能可达到28.62 dB。用双还原剂体系制备的镀银铝粉能应用于日常生活。

In order to improve the utilization rate of silver ions in Ag/Al powder plating solution,Ag/Al powder was prepared by improving the reducing agent system,using three different reducing agents:formaldehyde,glucose,tartrate and glucose to plating silver on the surface of aluminum powder.The microstructure of silver-plated powder was characterized by X-ray diffraction instrument,field emission scanning electron microscope and particle size analyzer,and its electromagnetic shielding performance was tested by vector grid analyzer.The results show that the silver coating is the best when glucose and tartrate are used as the reducing agent for the preparation of Ag/Al powder,and the silver layer does not fall off,which is better than the other two reducing agents.The compaction resistirity is as low as 11.3 mΩ·cm,and the vibration density of Ag/Al powder is 1.651 g/cm^(3),and the loosening density is 1.352 g/cm^(3);the average electromagnetic shielding performance in the frequency range of 8.2~12 GHz can reach 28.62 dB.Ag/Al powder prepared with a double reducing agent system can be applied to daily life.