Naval Undersea Research Program Final Report: Surface and Fluidization Studies of Coated Aluminum Particles for Improved Flowability
Abstract
The over-arching goal of this work was to study hydrophilic and hydrophobic silanes as surface treatment agents to improve the flowability of aluminum powder. The project was broken up into three separate research areas: (1) evaluation of hydrophilic and hydrophobic silanes for improved flow properties; selection of silane for further study, (2) fractional factorial experiment ofthe parameters associated with the solution phase treatment purpose including: humidity, stir rate, and cure time, and (3) scale-up from laboratory to pilot scale batch and subsequent flow and fluidization powder testing. The results of the first two research areas are reported in the dissertation of Lillian Mawby. The main hypothesis of this study is that the molecular level properties of the coatings are responsible for the macroscopic fluid properties. To this end, we firstly studied both hydrophobic and hydrophilic coatings to better understand the inter-particulate interactions responsible for improved flow. We found that hydrophobic silanes performed better, and, after a down-selection process, we selected phenyl-triethoxysilane (PTES) for scale up and further testing using a full feeder system. In addition to testing PTES, we also studied various aluminum treated/raw powders, including those processed using alternative methods and with different particle size distributions (PSD), to probe for differences in the powder flow patterns through visualization using density based imaging. We found few discernable differences based on treatment and PSD. The various surface treatments were also difficult to differentiate based on the results of the large scale flow testing. The most apparent difference came from the powder with the high percentage of fines; the particle density was found to be higher in the plume than in the other powders tested.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 28, 2021
- Accession Number
- AD1156521
Entities
People
- Bellamarie Ludwig
- Teri M. Baker
Organizations
- Pennsylvania State University