Additive Friction Stir Deposition - Understanding layer interfaces of aluminum builds

Recent improvements in additive friction stir deposition (AFSD) have enabled printing of aluminum alloys without the need for graphite lubrication. Modifications of tool geometries and tool materials; however, challenges remain to achieving acceptable properties in the build direction. Characterization of the as-deposited and heat-treated materials are evaluated by means of static and dynamic mechanical testing. Additionally, macro and microscopic characterization of layers, interfaces and fractures surfaces are presented to substantiate the results of mechanical testing. Comparisons between properties of builds made from discrete feed systems and continuous feed systems are presented as a means of demonstrating the robust nature of the process.