This study investigates the electrochemical corrosion resistance and fatigue life of as-fabricated Al 7075 parts made with high-rate additive friction stir deposition (AFSD). The relationship between microstructural changes and corrosion behavior was examined, along with assessments of bending fatigue life and damping capacity. Al 7075-T6 feedstock rods were deposited with a high feed rate (254 mm/min) and a high tool traverse velocity (276.9 mm/min). Tafel polarization test results revealed increases in corrosion current density from 1.9 × 10 ⁻⁴ A/cm ² for the feedstock to 3.3 × 10 ⁻⁴ and 3.8 × 10 ⁻⁴ A/cm ² for the deposition top and bottom layers, respectively. Additionally, the corrosion potential decreased after processing, with a more pronounced reduction observed in the bottom layers, from − 0.95 to − 0.99 V. Electrochemical impedance spectroscopy results showed that the high-frequency capacitive arc decreased after AFSD, indicating reduced corrosion resistance, especially in the bottom layers. Moreover, a decline in fatigue life was observed, decreasing from 221,000 cycles to 174,000 and 164,000 cycles for the top and bottom deposition layers, respectively. The reduction in fatigue life from the top to the bottom layers was accompanied by an increase in damping values in the as-fabricated parts. These changes were attributed to the microstructure alterations during the AFSD, particularly the nonuniform distribution and coarsening of MgZn-rich precipitates. Coarsening was more pronounced in the bottom layers due to prolonged heat exposure during processing.

In this paper, laser powder bed fusion (L-PBF) prepared GRX-810 samples with different yttria contents (from 0.3 to 1 wt%) were systematically examined. The mechanical properties and thermal properties were measured under as-built and Hot Isostatic Pressing (HIP) heat treated conditions. The results indicate that yttria content significantly affects the thermal properties of as-built L-PBF GRX-810. Higher yttria reduces thermal diffusivity and conductivity by up to 6% in of as-built samples. HIP restores thermal properties to low-yttria levels, indicating that L-PBF-induced microdefects and porosity, rather than composition, primarily cause the thermal degradation. Based on the mechanical testing results, yttria content up to 0.45% provides the most favorable strength–ductility balance in the present dataset. Higher yttria content (from 0.5 to 1%) leads to the reduction of the elongation from 27% to around 4% in the as-built samples. Following HIP, the yield strength decreases from ~ 785 MPa in the as-built state to ~ 685 MPa. The elongation increases from 4% in the as-built state to ~ 42%. HIP samples with yttria content less than 0.45% exhibit a high ductility at approximately 40% maximum elongation, while HIP samples with yttria content higher than 0.5% exhibit a moderate ductility of approximately 18% maximum elongation at failure. These thermal and mechanical performance studies provide valuable guidance for GRX-810 applications and provide a reference for further AM-ODS alloy optimization.

Additive friction stir deposition (AFSD) is a solid-state additive manufacturing process that enables the fabrication of fully dense metallic components without common fusion-related defects. Inconel 718, widely used in aerospace and energy sectors, requires high structural reliability; therefore, evaluating its response to AFSD is essential for advanced applications. This study investigates the effects of AFSD on IN718 by comparing the mechanical properties and microstructure of the as-deposited material with the feedstock condition. Tensile testing showed that the ultimate tensile strength (UTS) increased by 5% along the traverse direction, whereas elongation was reduced compared to the feedstock. In contrast, build-direction tensile specimens exhibited lower UTS and substantially reduced elongation, revealing mechanical anisotropy. Microhardness increased by 20%, consistent with substantial grain refinement from 11 µm to 3 µm due to dynamic recrystallization during deposition. X-ray diffraction (XRD) revealed no clearly detectable secondary phase formation after AFSD within the resolution limits of conventional XRD, suggesting that the increased hardness and traverse-direction strength can be partly explained by grain refinement. Elemental mapping detected oxygen-enriched Al/Ti regions at interlayer boundaries, which may contribute to the reduced build-direction ductility. Overall, AFSD refined the microstructure, enhanced hardness, and improved traverse-direction strength, while build-direction tensile testing revealed anisotropic mechanical behavior.