A ring-jig additive friction stir deposition method for efficient additive manufacturing of metal laminates

Metal additive manufacturing (AM) has attracted attention for producing high-mix, low-volume, meter-scale components, especially for industrial applications. However, conventional AM requires high-energy input, expensive powders, and long processing times, limiting scalability and cost-effectiveness. To overcome these challenges, solid-state AM methods are being explored for lower energy use and higher build rates. This study presents a solid-state AM technique derived from friction surfacing, in which uniform layers are formed by direct friction between a rotating metal bar and a substrate. The proposed method achieves a maximum build rate of 8,000 cm³ h^-1, while fusion-based AM method achieves 800 cm³h^-1 and conventional solid-state AM method achieves 2400 cm³h^-1 in maximum. Compared with other processes, the proposed method offers significant gains in deposition speed. Combining high build rate with sound interfacial bonding, the proposed method provides a promising approach for scalable, cost-effective production of large structural metal components.