Ion Beam Modification of Powders in the Rotating Wing Drum

Most of the properties of powders are determined by their surface characteristics. Therefore, surface modification techniques are a promising tool for powder modification. Among these are ion beam methods such as ion implantation, ion beam sputtering and ion beam assisted deposition. These techniques are typical line-of-sight processes. Only those parts of a workpiece, or for the present case a powder particle, which are directly turned towards the source of ion or atom beam and are not shaded off, are treated properly. This renders uniform treatment of powders difficult. In the present study, facilities for ion beam treatment of powders are described. The features of a rotating wing drum for agitating the powder while under bombardment by an ion beam are discussed in detail. As an example, results of ion beam sputter deposition of alumina powder with gold are presented. Trace analytical methods were used to determine the amount of de posited gold in dependence on the process parameters. The powder grain surfaces were investigated with electron microscopy.