Experimental study on the alumina fine powder internal compression characteristics under gas pressurization

The compression characteristics at the different positions inside a powder bed under gas pressurization were experimentally studied by a visualization tank. It was found that the pressurization rate had an important effect on the powder compression which accelerates the arrival of high pressure. The compression characteristics of the beds at different positions differed significantly and the compression ratio increased with the increasing bed depth. The smaller the pressurization rate, the more significant the difference in compression ratio of different powder layers; conversely, the compression processes of different powder layers tend to be consistent at higher pressurization rates. The prediction model of relative compaction density variation was established with the error within ±5%. The paper provides an important reference for regulating the flow of the compressed powder bed.