Properties of AA7075 Produced with Additive Friction Stir Deposition – Graphite Free

Recent improvements in additive friction stir deposition (AFSD) have enabled printing of 7xxx series aluminum alloys without the need for graphite lubrication. Modifications of tool geometries and materials in addition to updated processing parameters have improved deposition rates while printing materials that can achieve T7 properties of forgings. A discussion of the tooling, machine parameters and heat-treatments that enable these properties are presented. 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.