Influence of Type of Process Control Agent on the Synthesis of Ag8ZnO Composite Powder

In this study, the effect of different types of process control agents on the particle size and morphology of Ag8ZnO composite powder was investigated. For this purpose, commercial elemental silver and zinc oxide powders were initially mixed with different types of process control agents and then milled in a two stationary planetary-type ball mill with a ball-to-powder weight ratio of 10:1 and a milling speed of 300 rpm. The usage of process control agents is advantageous to eliminate or minimize agglomeration and to decrease the tendency of excessive cold welding among powder particles. However, contamination from the process control agent essentially leads to interstitial contamination, since the process control agents used are mostly organic compounds containing carbon, oxygen, and nitrogen. Hence, it is of importance to investigate the nature of PCA and milling duration that both influence the performance of electrical contacts. Characterization of starting and ball-milled powders was investigated using scanning electron microscopy and laser diffraction analysis. It was found that final powder particle sizes significantly affected by the nature of process control agent. Besides, morphology of powders and microstructural analyses prove that the type of process control agent is also crucial in obtaining homogeneous mixture of the constituent powder particles.