During this year's TCT Asia 3D Printing Exhibition and Zhuhai Air Show, "mass manufacturing" has become the latest vocabulary to describe metal 3D printing technology. "Providing more possibilities for mass production of aerospace parts" and "for mass production" not only makes us wonder, is metal 3D printing developing so fast and so reliable?
The reason for the brand owner to make such publicity is because there are reliable cases to support this rhetoric. The most typical representative is that GE Aviation has achieved the manufacture more than 100,000 nozzle heads and applied them to the most advanced engines:
GE9X on Boeing 777X
LEAP-1A on Airbus A320 NEO
LEAP-1B carried by Boeing 737MAX
LEAP-1C on Chinese C919
It combines 20 parts made by welding into a precise whole, which reduces the weight of the product by 25% compared with the previous generation, improves durability by 5 times, and increases the cost-effectiveness by 30%. Its complex feature structure requires only It can be manufactured by the 3D printing process. The success of this case shows that metal 3D printing is feasible for mass production.
Although domestic cases of mass manufacturing of metal 3D printing in the aerospace field have not been published, clues can still be captured. In the latest application case of the Sixth Academy of Aerospace Science and Technology, it is stated that in the development and manufacturing process of the 85-ton open-cycle liquid oxygen kerosene engine, "the key components of 3D printing have been tested dozens of times in long-term tests. assessment". This proves from the side that the quality of parts manufactured by metal 3D printing technology is reliable and can be accepted by the aerospace field. Next, from a production point of view, what factors affect mass production in the aerospace sector will be described.
1. Product consistency, a key factor for repeatable manufacturing
The realization of batch manufacturing means that each part manufactured by metal 3D printing in a single batch or in multiple batches is completely consistent in terms of part quality, performance, and dimensional accuracy, that is, the technology has achieved repeatable manufacturing quality. This puts strict requirements on printing equipment and process standards.
The tuning of the equipment must meet strict standards and be able to achieve repeatable manufacturing quality, so as to have the basic conditions for mass production. But this is only a systematic description, but it involves a wide range, such as the removal of smoke and airflow regulation in the forming space during the printing process, the stability control of laser power, and the regulation of the energy of each part of the platform within an acceptable range, printing The oxygen content control in the chamber and the post-processing required after the construction is completed, etc., the number of sensors that need to be arranged can reach thousands. GE has also carried out detailed research, analysis, and transformation on the acquired Concept Laser printers to meet the capacity of mass manufacturing.
2. Well-trained engineers are critical
For metal 3D printing technology, a lot of professional knowledge is bound to be required, but it does not require one person to be multi-skilled. This technology involves a lot of technical details, such as design for additive manufacturing, skilled operation and maintenance, printing process development and material quality control, post-processing, and so on.
Almost all of these involved processes will directly affect whether the manufacturing quality of the product is uniform. For suppliers committed to providing services to the aerospace industry, talents in these links are indispensable, especially those who are well-trained engineers. Developing engineers with these specialized skills is expensive and time-consuming, but necessary.
3. Manufacturing costs must continue to decrease
It should be pointed out that 3D printing technology will not be widely adopted and mass-produced unless the return on investment exceeds other available production methods. For the aerospace field, cost does not seem to be the most important thing, but cost still affects whether mass production can be achieved.
The high cost of the machine itself is a major problem. However, after ten years of technology accumulation and R&D iterations, the equipment cost of 3D printers has dropped considerably compared to the early days. Likewise, there is a consistent trend in material costs. No matter from the perspective of mature technology or from the perspective of competition, the continuous reduction of manufacturing costs will be inevitable.
4. There will be more and more automatic adjustments and production
Minimizing human error is very important for metal additive manufacturing. For example, when adjusting the parameters of spot size and multi-laser overlapping, the judgment of engineers may be different. Therefore, some equipment manufacturers such as Farsoon Hi-Tech independently developed a "Multi-laser intelligent calibration system" which solves the challenge of multi-laser overlapping consistency to the greatest extent, making the printing quality and performance more uniform.
Other human-induced errors include leveling of build substrates, powder cleaning of piping inside parts, and support removal and post-processing. Current software and hardware are making these processes smarter. Although the current degree of automation is still limited, it can be seen that this will be a trend.
Summarize
The application advantages of metal additive manufacturing technology in the aerospace field include liberated design, high material utilization, low manufacturing cost, and rapid manufacturing. After experiencing early doubts, it began to develop rapidly.
Metal 3D printing is not just "can be printed", the performance must meet the installation requirements, mass production must be stable, efficient, and consistent, the cost must continue to be reduced, and the innovation ability of design and process improvement and upgrading must continue to improve. Only in this way can it become an indispensable part of the manufacturing supply chain, and this once "non-mainstream" process can survive in the cold winter.