Throwing Power in Chloroaluminate Ionic Liquids: Effects of Metal Concentration, Additives and Waveform on Aluminum/Aluminum Alloy Deposition on Complex Geometries

Monday, 14 October 2019: 11:00
Room 310 (The Hilton Atlanta)
J. G. Abbott, S. Lucas (Xtalic Corporation), W. Li, and W. Zhang (United Technologies Research Center)
Al deposition from chloroaluminate ionic liquids necessitates the use of consumable anodes and near 100% plating efficiency in order prevent irreversible breakdown of the electrolyte. A significant side effect of this high plating efficiency is poor deposit thickness uniformity across current density gradients. For simple or axisymmetric geometries under ideal plating conditions it is straight forward to mitigate such issues through traditional thieving or shielding. However, as part geometries become more complex, and plating conditions less ideal (i.e. barrel plating of small parts), methods of improving poor throwing power resulting from secondary current density effects become less obvious. Addressing this issue is critical in enabling Al plating technologies to progress commercially. We have explored the effects of metal concentration, additives and plating waveform on deposit thickness uniformity for rack and barrel plated parts of increasing geometric complexity in order to minimize plating thickness distribution and improve throwing power of [AlCl3:EMIMCl] chloroaluminate electrolytes into high aspect ratio features.