The effect of gas phase polydimethylsiloxane surface treatment of metallic aluminum particles： Surface characterization and flow behavior

作     者：Bellamarie Ludwia Jennifer L. Gray 

作者机构：Applied Research Laboratory The Pennsylvania State University North Atherton Street State College PA 16801 USA Materials Research Institute The Pennsylvania State University USA 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2017年第15卷第1期

页      面：92-101页

核心收录：

学科分类：07[理学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：supported by the Office of Naval Research 

主　　题：Aluminum powder Polydimethylsiloxane X ray photoelectron spectroscopy Diffuse reflectance infrared Fourier transform spectroscopy Flowability FT4 powder rheometer 

摘      要：Aluminum particles were exposed to gaseous polydimethylsiloxane （PDMS） to produce a hydropho- bic surface coating for enhanced flow and fluidity. Surface retention of the intact PDMS was confirmed through infrared and X-ray photoelectron spectroscopy. Transmission electron microscopy was used to image cross-sections of the treated particles and energy dispersive spectroscopy element maps demon- strated the presence of a surface layer consisting of silicon and oxygen. Density measurements provided evidence for improvements in the Hausner ratio and Carr index of the PDMS-treated aluminum, indicating a reduction in inter-particulate cohesion through increased bulk density. Stability, compressibility, shear, aeration, and permeability of the particles were assessed by powder rheometer. The compressibility was reduced by approximately 32% following surface treatment, revealing a reduction in void space, while Mohr＇s circle analysis and shear testing determined that the extrapolated cohesion value was reduced by approximately 53% and the flow factor at 6 kPa was doubled. Aeration testing showed that the air velocity required to obtain a fluidized bed was on the order of 0.35 mm/s for the treated powder, whereas the raw powder could not be uniformly fluidized. PDMS may be a viable option for the large-scale treatment of aluminum powder for flow applications.