Depth prediction of plastic vortex toward vortex flow-based friction stir additive manufacturing

Vortex flow-based friction stir additive manufacturing (VFSAM) advances conventional FSAM by replacing the stir tool with a plastic vortex, eliminating tool wear in high-melting-point metals. However, the precise control of the vortex depth (which directly affects the deposition layer thickness and bonding quality) still faces the challenge of selecting process parameters. This study used the Order of Magnitude Scaling (OMS) method to establish a one-dimensional (1D) vortex depth analytical model, which enables rapid parameter selection for desired layer thickness. The core of the OMS method is to ignore the influence of secondary physical quantities and only retain the magnitude relationship of dominant factors, thereby achieving efficient parameter screening within the allowable error range. The 1D analytical model was applied to Ti-6Al-4V titanium alloy , with an objective function f ( N , R ) = NR identifying optimal parameters for maximum vortex depth. For Ti-6Al-4V, the optimal solution is f ( N , R ) = 6000, providing ideal parameters for achieving maximum depth. This streamlines the process optimization, enhancing VFSAM efficiency for high-performance applications.