Comac C919 is a modern commercial airliner, developed by Comac, an aerospace manufacturing company from China. The aviation program started in 2008, with the prototype being created in 2011. In 2017, the Comac C919 flew for the first time and it said to enter commercial service around 2020. What makes this airliner unique? Well, there are many features to take into consideration but one seems to stand out the most and that is the usage of titanium for different parts.
According to the team of specialists who have worked on the aviation program, the airliner has titanium spars, which have been created with the help of 3D printing technology. Titanium alloy has been used for other parts of the aircraft, allowing Comac to gain a competitive advantage over other powerful names of the industry (Airbus, Boeing). It seems that the usage of titanium alloy has allowed for an important reduction in the overall structural weight, which will automatically transport into fuel and operation savings.
Comac collaborated with different companies for the aviation program, including a titanium producer from Russia (this was bound to supply the titanium forgings for the Comac C919). But the most interesting piece of news comes from the researchers in Xi’an, who have managed to use 3D printing technology, in order to create titanium wing spars from the aircraft in question. Not only is this equipment a true innovation in the aerospace field but it has managed to meet every standard required for passenger airplanes.
The aerospace industry is one that changes on a regular basis, with innovation being a word that is heard quite often. The competition is stringent, as there are a lot of aerospace manufacturers who are interested in gaining a piece of the action. For this reason, resorting to additive manufacturing and 3D printing technologies seems to be the logical thing to do. The main idea was to create top-of-the-line aircraft parts, without resorting to traditional manufacturing methods (these can be costly, both in relation to time and money).
Interestingly enough, the 3D printing technology can be easily used for the creation of new aircraft parts, allowing for the almost immediate replacement of those that are damaged. The technology is also known as LAM or laser additive manufacturing, being used for the reparation of aircraft parts. The main advantage is that the parts can be repaired, without their actual performance being affected at all.
The wing spar developed by the Chinese specialists is considered the world largest 3D printed component, made from titanium. It is a load-bearing structure that will reduce the weight of the aircraft, providing countless benefits on the side. This innovative equipment demonstrates how far titanium LAM has come, ever since the first research projects undertaken by China in 1995. Today, LAM is used on a regular basis, such as for the development of the central wing spar for the Comac C919.
The research and prototype development was undertaken by Chinese specialists, working at the State Key Laboratory of Solidification Processing, at the Northwestern Polytechnical University in Xi’an. The Comac C919 is actually the first aircraft destined for passenger/commercial service, which will have a structural element created with the help of 3D printing technology.
The fact that the aerospace industry has began to rely more and more on the usage of titanium is not a secret. In truth, titanium is one of the most used materials by the specialists in this industry, as it has a wide range of benefits to offer. The aircraft parts that are made from titanium present excellent strength and they are lightweight, especially in comparison to the ones made from steel or alloy steels.
The usage of the LAM technology for the creation of the central wing spar also ensured that this aircraft part will possess the standard mechanical properties of the industry (as forging parts already present). The technology, if used on a wide-scale basis, would allow for lower costs, in regard to the manufacturing of titanium parts (to 5% of the original costs). Moreover, if we were to compare the traditional manufacturing processes, we would also discover that a huge amount of money can be saved (up to 90%). As it was already mentioned, the usage of titanium would reduce the overall weight of the aircraft, which would mean lower operating costs.
The defense industry was the first one to use 3D printing and LAM technology, in particular to create innovative parts for military planes. Comac C919 paved the way for commercial applications, demonstrating that the aerospace industry is and will always be an essential market for 3D-printed parts. The Chinese aerospace manufacturer resorted to 3D printing technology, in order to bring the aircraft industry to the next level and gain the much-needed advantage over established companies. It was in 2001 that they began to study how this technology could be used for the making of aircraft parts, paying more and more attention to titanium alloy structural components.
Apart from the load-bearing wing spar, which was printed as one piece, Chinese specialists also used the 3D printing technology for windshield frames and landing gears (made from titanium alloy). The central wing spar remains the star, especially if we stop for a moment and compare its weight – only 136 kg – with the one of the forged part – approximately 1,607 kg. Moreover, performance tests demonstrated that 3D-printed aircraft parts deliver better results than the forged parts.
Even the vertical tail of the Comac C919 has attachment fittings made from titanium alloy, demonstrating the incredible versatility of the material. Titanium not only meets the requirements of the aerospace industry but it also guarantees the needed durability and strength for commercial flights. There are several advantages that 3D-printed titanium parts bring to the table, as it has happened with the Comac C919. First of all, one has the opportunity to develop equipment that has a complex design. Thanks to the LAM technology, it is easy to replicate the mechanical properties of the prototype. 3D printing also provides the advantage of quick turnaround and facile re-design, in case the latter is necessary.
The 3D printer simply follows a computer blueprint, in order to develop titanium aircraft parts, such as the central wing spar of Comac C919. The technology can be further extended to titanium alloy airframes, landing gears and even engine parts (disks, turbine blades). It contributes to the overall weight reduction of the aircraft, reduces fuel consumption and brings down operating costs.
Additive manufacturing technology will change the way the aerospace industry functions, with Comac C919 standing as the perfect example for what lies ahead. It will help companies from all over the world to develop aircraft parts that are highly sophisticated, allowing them to save precious resources and move further and further from traditional manufacturing methods. Basically, it will guarantee that the production of aircraft parts is not only cheaper but also faster.
While one cannot deny the significance of traditional manufacturing methods, there are drawbacks to take into consideration. For example, there are still a lot of aircraft parts developed with the help of injection molding. The main drawback to this particular technology is related to the mold design; no part can be manufactured without the mold design being created in the first place. This automatically translated into higher costs for such parts. By comparison, 3D-printed parts are more efficient and savvy from an economic point of view. The amount of time necessary for production and assembly is considerably reduced, allowing companies such as Comac to gain competitive advantages and come up with innovative parts, as the central wing spar for Comac C919.