Abstract: In repairing thin-walled variable-width blades through gas tungsten arc (GTA) and wire-based deposition, the management of collapse at sharp corners and the maintenance of uniform layer height pose significant technical challenges. Referring to the technical requirements for the repair of the damaged blisk blade, this study explored the technology of robot-operated GTA and wire-based deposition by designing a simulated blade of TC4 titanium alloy. A method for controlling the collapse of sharp corners and deposition by a shape-controlled restraint sheet was proposed. Aiming at varying heat dissipation conditions at the interface, with precise regulation of the heat input distribution through pulse current processing, consistent deposition width and height were achieved for the first five layers. The forming width of the deposition layer at this moment was uniformly distributed, and the fluctuation range of the upper surface height was within ±0.12 mm. Subsequently, 40 layers were deposited with consistent deposition parameters. The deposition area exhibited a wall thickness control accuracy of ±0.17 mm and each layer displayed a predominantly flat upper surface. The microstructure of the simulated repair part was fine and uniform with an average ultimate tensile strength and elongation reaching 92.5% and 94.7% of the matrix, respectively. This provides a solid technological foundation for high-precision blade repair.

Key words: GTA and wire-based deposition, shape-controlled restraint sheet, current regulation, pulse wire feeding, forming control