颗粒级配提高球形银粉振实密度的研究

Study on particle gradation to improve the tap density of spherical silver powder

以链烷醇胺为分散剂,用对苯二酚C6H4(OH)2还原硝酸银,通过调节硝酸银浓度、还原剂配比以及分散剂添加量等工艺参数实现对银粉粒径的控制。用扫描电镜(SEM)表征银粉的形貌、球形度和分散性;用激光粒度分布仪测试不同粒径银粉的粒度分布;参照GB 5162-85测试不同粒径粉体和级配后粉体的振实密度。结果表明:制备的银粉表面粗糙度低、球形度和密实度高,其流动性随粒径的减小变差,振实密度随之减小。合适的颗粒级配能有效提高粉体的振实密度,其最大值达到4.75 g/cm^3。

The alkanolamine is used as a dispersing agent,and the silver nitrate is reduced by hydroquinone C6H4(OH)2,and the particle size of the silver powder is controlled by adjusting the process parameters such as the concentration of silver nitrate,the ratio of reducing agent and the amount of dispersant. The morphology,sphericity and dispersibility of silver powder were characterized by Scanning Electron Microscope(SEM). The particle size distribution of silver powder with different particle sizes was tested by laser particle size distribution analyzer. Tap density of powders with different particle sizes and the powders after grading were tested with reference to GB 5162-85. The results show that the prepared silver powder has smooth surface,high sphericity and compactness,and its fluidity deteriorates with the decrease of particle size,so the tap density decreases accordingly. Proper particle gradation can effectively improve the tap density of powders which can reach up to 4.75 g/cm^3.