Novel additive friction stir deposition method for highly efficient fabrication of metal laminates

Metal additive manufacturing (AM) has recently garnered attention because of its potential to produce high-mix, low-volume products on a meter scale, such as spacecraft components. However, most AM methods demand high-energy input, metal powders, and prolonged production times. To reduce production costs and increase build rates, AM processes utilizing friction heat are increasingly being explored. Among these, friction surfacing, a process that involves the formation of layers through direct friction between a metal bar and a metal plate, offers a promising solution for reducing energy and time requirements. Nevertheless, achieving uniform layer shapes via friction surfacing remains challenging. In this study, we developed a novel additive friction stir deposition (AFSD) method based on conventional friction surfacing. This novel AFSD method successfully produces layers with superior surface quality and robust joining. Additionally, the build rate was significantly improved by applying a higher load to the bar against the plate. This increased load enabled the novel AFSD method to achieve an exceptional build rate compared with conventional AM techniques. To summarize, compared with existing methods, a novel AM approach is demonstrated for fabricating metal objects with lower energy consumption and higher time efficiency.