Additive Manufacturing Lightweight Seat Frame Saves up to 550 kg
Autodesk has designed a generative lightweight seat frame for commercial planes that saves up to 550 kg per plane and thus fuel for millions of dollars. This is one of example how the casting sector benefits from this further development of additive manufacturing by the use of 3D printing.
Generative design and 3D printing are new territory for most companies. Many of them are still waiting for additive manufacturing technologies to become more mature. There are practical reasons for this. Today, for example, there are still less than a dozen materials available for additive metal manufacturing. For traditional metal casting, on the other hand, hundreds of different alloys are available. In addition, huge components can be produced by metal casting, while metal printers are limited to small parts. Another important aspect is the cost and time involved in the manufacturing process. Equipment for direct laser melting is extremely expensive and the components produced with it require a great deal of post-processing. Certification of 3D printed parts is also difficult. Metal casting, on the other hand, is a well-known and proven process. Despite the advantages of additive manufacturing, such as the possibility of producing particularly complex structures, a great deal of time and money can often be saved by resorting to traditional metal casting.
3D Printed Mold Enables Mass Production of Generative Designs
Metal casting and additive manufacturing unfold their full potential only in combination with each other. With the help of generative design and digital optimization, high-performance structures can be designed using specialized software. The casting molds for these structures are produced by metal-free additive manufacturing. Then modern casting processes using the appropriate metal are used for the final part. An impressive example of the effective combination of both processes is a generatively designed lightweight seat frame for commercial planes developed at the Autodesk Pier 9 Technology Center in San Francisco. The project combines traditional manufacturing methods and modern technologies such as generative design and industrial 3D printing.
"Additive manufacturing has a huge potential to determine the future of production. For product developers and designers, however, it is still an extremely new concept. The metal casting process, on the other hand, has been perfected over thousands of years. Countless experts, engineers, foundries and factories have in-depth expertise in this field. This is incredibly valuable, especially for the production of components that are especially complex, such as our seat frame," explains Andreas Bastian, Principal Research Scientist at Autodesk.
The manufactured seat frame is based on a design developed generatively by a software algorithm in Autodesk Netfabb. Series production of the component takes place in a hybrid manufacturing process using additive 3D printing and traditional metal casting.
Seat Frame Made of Magnesium Reduces Weight by 35 % Compared to the Aluminum Version
For the production of the seat frames, Autodesk's developers were supported by an experienced partner: The Aristo Cast foundry in Michigan. "We were immediately enthusiastic about the idea from Andreas and Autodesk. We also learned a lot about advanced design and optimization possibilities for the manufacturing process. Both are still relatively new approaches in our industry," explains Paul Leonhard, Vice President of Aristo Cast. Instead of using aluminum, which is widely used in aircraft construction, the experts from Michigan recommended a magnesium production process to manufacture the seat frame as initially planned. This approach promised additional weight savings of 35 % compared to an aluminum variant.
For the hybrid manufacturing process, the team starts by printing a plastic model of the seat frame, which is then coated with ceramics. The plastic part can then be melted away and liquid magnesium poured into the resulting ceramic mold. The result is a seat frame that is 56 % lighter than current aircraft models. This is due to the material used and the generatively generated grid structure. In aviation, where every gram counts, this is tantamount to a revolution. If a 615-seater Airbus A380 were equipped with seats of this kind, fuel costs of $ 100,000 could be saved within one year.
The project also dispels the myth that the production of components by metal casting takes about one and a half years. In fact, a company using the process described only needs two days to manufacture the end product — i.e. in less time than would be required in most cases of metal printing.
Investment Casting and Generative Design Save Kerosene and Costs
The special casting and melting process allows for detailed accuracy within the sub-millimeter range. Even a fingerprint on the model would later be visible on the end product. For the aviation industry, this approach offers undreamt-of possibilities, and could save enormous amounts of kerosene, CO 2 and costs in the long term. In an Airbus A380, the use of seat frames would lead to a weight reduction of 557 kg, which would save 63 tons of kerosene and 190 tons of CO2 per year and aircraft. Converted to a fleet of 100 aircraft and a period of twenty years, this equals 126,000 tons of CO2, and over 200 million dollars in fuel costs.
This article was first published by konstruktionspraxis