Weight reduction in aircraft systems is of great significance for reducing the consumption of aircraft fuel, and therefore has always been crucial in the development of aviation equipment. The weight of electromechanical aviation products in aircraft systems accounts for approximately 30% of the whole aircraft, and the number of electromechanical parts accounts for approximately 60%, and are characterized by large weights and numbers, as well as complexity. Currently, there are two main approaches for reducing weight: upgrading materials and design. Conventional structural optimization and applications of lightweight metal materials to reduce weight have reached the optimization limit and are gradually becoming unable to meet new lightweight demands. Therefore, there is an urgent need to develop new materials, structures, and technologies to realize lightweight designs and manufacture electromechanical aviation products. Metal laser additive manufacturing technology with integrated design and manufacturing capabilities of material-structure-performance-function can provide advanced methods for lightweight design and high-performance manufacturing of electromechanical aviation products, improving the innovative design and rapid manufacturing capability of electromechanical aviation products and promoting the rapid development of the electromechanical aviation industry.

With its ability for highly flexible manufacturing and precision forming, laser powder bed fusion (LPBF) technology will be increasingly used in the design and manufacture of electromechanical aviation products. MOOG was the first company to apply LPBF technology to manufacture complex hydraulic parts and has accumulated considerable experience in pore control and material performance verification during the printing process of hydraulic products. MOOG has developed a new actuator structure and the next generation of aviation motor manifolds based on LPBF (Fig. 6). Based on LPBF technology, Liebherr developed a titanium hydraulic integrated valve block, which is 35% lighter than the original product and was certified for its first flight on the Airbus A380 in 2017 (Fig. 8). Domin Fluid Power, a British manufacturer of fluid power systems, developed a direct-drive servo valve using LPBF technology (Fig. 8). Materials Solutions developed a high-performance aerospace titanium alloy hydraulic manifold using an additive manufacturing (AM) design (Fig. 8). The hydraulic manifold is precisely shaped based on LPBF technology. The hydraulic manifold can satisfy the requirements of the most stringent aerospace working conditions while ensuring high safety and reliability. In the field of hydraulic products, an integrated hydraulic steering gear shell was successfully developed by Nanjing Engineering Institute of Aircraft Systems based on LPBF (Fig. 9), which demonstrated that LPBF can effectively solve the problems of multiple oil paths, multiple process plugholes, and complex structures in traditional steering gears. Compared to the traditional steering gear structure, the 3D printed steering gear shell reduced weight by approximately 51%, flow resistance by approximately 48%, and the manufacturing cycle by approximately 70%, showing high product reliability. In the field of fuel products, an integrated air refueling fuel hood was successfully developed by Nanjing Engineering Institute of Aircraft Systems based on LPBF (Fig. 11). By using a pneumatic edge layout, integrated precision forming of the fuel hood was realized. Compared with those by traditional manufacturing methods, the AM fuel hood achieves integrated airfoil forming, which significantly improves the yield and reduces the component weight and production cycle by approximately 41% and 50%, respectively. In the field of environmental control products, an integrated ejector was successfully developed by Nanjing Engineering Institute of Aircraft Systems based on LPBF (Fig. 13). The ejector realized an integrated design of the main pipe and ejector nozzle structures, which could reduce the risk of the manufacturing process. Compared with that by the traditional manufacturing method, the weight of the ejector was reduced by approximately 64%, processing cycle was shortened by more than 50%, and the heat transfer performance was improved by 9.3%. Moreover, multistructure integrated forming was realized, and the reliability of the product was greatly increased.

AM technology can help realize the integrated design and manufacturing of materials, structures, performances, and functions, aiding in the development of smart and lightweight electromechanical aviation products. Currently, AM is applied in the manufacture of various types of electromechanical aviation products, demonstrating great application potential. In the future, digital twin-driven AM technology, hybrid additive and subtractive manufacturing technology, and multimaterial AM technology will be the key research areas for the development of aviation electromechanical products.