Aircraft landing gear is a class of components that are subjected to enormous forces, and in order to adapt to the stressful environment, these parts are forged from high-strength steel. However, since the introduction of titanium alloys, aircraft landing gear gradually switched to titanium alloy forgings, because titanium alloys have both high strength and low density, but also can reduce its mass by more than 25%, which is very important for aircraft. Aircraft landing gear using titanium alloy for Ti-10V-2Fe-3Al, tensile strength of 1190MPa, almost 7075 aluminum alloy 2.2 times, Boeing B777 aircraft landing gear many parts with its forging. Landing gear is still in use Ti-6Al-2Sn-2Zr-2Mo-2Cr alloy has high strength and toughness, but the price is higher. In addition, Ti-6Al-4V alloy is mostly used for forging helicopter landing gear parts, is the most widely used aerospace and general-purpose machinery titanium alloy, lower price, strength and performance than the above titanium alloy is low.
Aero-engine blade working conditions are extremely harsh, not only high temperature, but also to withstand high pressure and high-speed airflow scouring. In the "three high" harsh environment, aero-engine blades are very easy to damage, especially the tip of the blade, so the maintenance workload. According to the U.S. "Aviation Week" website reported on September 15, 2023, in order to reduce the maintenance workload and extend the working time of the blade, the U.S. Optomec (Optomec) and Acme Robotics Systems (Acme) about 2 years to jointly develop the maintenance of aero-engine titanium alloy pressurized airfoil blades of the automated work cell is the world's first. The repair system was designed and manufactured to repair titanium compressor blade tips that have been worn out during engine operation, as well as repairing nickel-based alloy blade tips and blade leading edge damage. The automated work cell consists of three stations for blade tip grinding, 3D printing laser cladding and post-processing, with an automated pallet loading and unloading station, a pallet turning station and a robotic material handling system, and can be equipped with other features such as an automated coordinate measuring machine and a cleaning station.
Optomec says the automated workcell offers a number of advantages over traditional processes for repairing titanium blades such as CNC machining and tungsten inert gas welding (TIG): the speed of completing blade finishing is approximately three to four times faster than CNC machine finishing or manual finishing; the quality of the repairs is more consistent compared to manual processes; the cost is reduced by more than 70% without the need for manual welding and manual finishing, the quality of repair is greatly improved. Optomec says that the use of efficient and repeatable robotic finishing technology enables engine repair centers to greatly improve the quality of work and reduce repair costs. The automated robotic system, which is capable of repairing 85,000 titanium compressor blades per year, has been certified by civil aviation regulators in several countries, and long-term commercial applications have shown it to be completely safe and reliable.
According to the British aero-mag network reported on September 17 this year, the British Institute of Aerospace Technology (ATI) launched a research and development project called "landing gear industrial breakthrough (Ⅰ-Break)", an investment of 22.5 million pounds. The project is led by Airbus, participating in the work of 15 companies, research institutions and colleges, will be the first time in the world 3D printing aircraft landing gear parts.
The Ⅰ-Break project consists of four work packages: WAAM3D is responsible for developing the industrialization of arc 3D printing production speed improvements, microstructure and mechanical property control for high integrity structural applications, industrialization of in-line non-destructive flaw detection, and the production of prototype parts of the appropriate sizes and complexity on an upgraded version of the RoboWAAM system; and Cranfield University is primarily responsible for the research of new WAAM processes and solutions and validation of the deposition of key alloys; the University of Strathclyde is responsible for innovative in-line flaw detection technologies; PeakNDT, a manufacturer of high-performance conventional and phased-array ultrasound instrumentation, is also responsible for in-line NDT research.
The research and development of 3D printed aircraft landing gear components, which could reduce time to market, improve product quality and reduce CO2 emissions by 20%, is scheduled to be completed by 2026. The world's aircraft landing gear components manufacturing process will gradually shift from forging to 3D printing.
