3D Printing a Large Aircraft: An 81-Year-Old Academician's "New Long March"
Lu Bingheng, photo provided by the interviewee
■ Reporter: Tian Ruiying, China Science Daily
On a table full of materials sits a model of the C919 aircraft, with several strips of capsule medicine scattered beside it. To save commuting time, 81-year-old Lu Bingheng, an academician of the Chinese Academy of Engineering, has moved into the office next door. Every morning, his wife reminds him to take his medication on time—five stents have been implanted in his heart.
Lu Bingheng is the founder and pioneer of additive manufacturing technology in China. Over the years, in order to accelerate the use of 3D printing to manufacture major sections of large aircraft—such as the nose, tail, fuselage, and wings—and to open a new Chinese track for aircraft manufacturing, his work intensity has never changed, with more than 100 days each year spent on business trips, research, and visits.
Just the day before the interview, Lu Bingheng had landed in Xi'an from Sichuan in the early morning. He told China Science Daily that "3D printing large aircraft" is his biggest goal at present. In his view, the technical route of "3D printing large aircraft" not only serves the nation's major needs, but also "is expected to drive a market with an annual output value of hundreds of billions of yuan."
As the first person to propose the technical route of "3D printing large aircraft," Lu Bingheng revealed that the preliminary technical demonstration has been completed, and the research and design of large-scale additive manufacturing equipment have been initiated. He hopes to complete special equipment design, process development, and airworthiness certification within 4 to 5 years, ultimately achieving industrialized mass production.
Multiple Twists and Turns, Never Forgetting the Aerospace Dream
Lu Bingheng's aerospace dream began in his youth.
In 1945, Lu Bingheng was born in a small county in Bozhou, Anhui Province. During middle school, he saw a report in the newspaper about Qian Xuesen returning to China to develop rockets, and his heart surged with excitement. He aspired to devote himself to the aerospace industry. Due to special circumstances, he was unable to apply for aerospace majors involving confidentiality, and ultimately enrolled in the Mechanical Manufacturing major at Hefei University of Technology.
Studying something he hadn't chosen, Lu Bingheng was somewhat disappointed. Fortunately, he had a strong passion for mathematics and ranked among the top students. It wasn't until an internship, when he operated a lathe himself and watched the cutting tool "cut iron like mud," that he felt "studying mechanical engineering isn't so bad after all."
After graduating from university, Lu Bingheng was assigned to Sanmenxia Zhongyuan Measuring Instrument Factory as a lathe worker, working 8 hours a day for over five years. Later, he became the factory director and formally came into contact with practical engineering problems. Although he didn't realize his ideal, thinking that he could solve the problem of feeding more than 100 workers, he felt somewhat comforted.
In 1979, China officially resumed graduate student enrollment. At that time, Lu Bingheng was 34 years old and already the father of two children. He decided to give up his stable job and apply for graduate studies at Xi'an Jiaotong University (XJTU). Many people advised him: "Why take this path?" During his graduate studies, factory leaders came to visit, hoping he would return to take over after graduation. Lu Bingheng politely declined, because he always remembered the dream from his middle school years.
This time, Lu Bingheng did not directly choose an aerospace major. Having left campus for over a decade, he knew his foundation was weak and decided to start by studying mechanical manufacturing technology. He also felt that picking up textbooks again was not easy—just moments after chatting enthusiastically with others, he would fall asleep within ten minutes of opening a book. It took him more than half a month just to be able to read without dozing off.
His mentor, Professor Gu Chongxian, with his spirit of moving west and emphasis on engineering practice, influenced Lu Bingheng's life. Gu Chongxian graduated from the Mechanical Engineering Department of Chongqing Central University, and later worked as an engineering practitioner at the Central Machinery Factory and China Industrial Corporation. In 1945, after going to the United States for further study, Gu Chongxian chose not to pursue a university degree but to work as an apprentice engineer in an enterprise. After returning to China, he rooted himself in factories. In his 60s, Gu Chongxian led young teachers to visit more than 20 cities and dozens of enterprises, compiling the influential textbook "Mechanical Manufacturing Technology" from real production examples.
"I admire him very much," said Lu Bingheng.
After receiving his master's degree, Lu Bingheng stayed at the university to teach while pursuing his doctorate. During his doctoral studies, he solved the vibration isolation design problem for complex structures containing viscous damping and viscoelastic damping. The program he developed was bought by aerospace units for protecting launch instruments and was later applied to aerospace hospitals.
By the time he obtained his doctorate, Lu Bingheng was already 41 years old, and he had successfully connected with the aerospace industry. Regarding those years when his dream was diverted, he said: "History develops in a tortuous way; one can only adapt to social development. But you must not give up—you have to continuously accumulate abilities. When opportunities come, seize them."
"Suppressing" Foreign Equipment
In 1992, Lu Bingheng went to the University of Michigan in the United States as a visiting scholar. While visiting an automobile company, he saw 3D printing equipment for the first time. At that time, the technology was called "rapid prototyping," which could directly convert three-dimensional digital models into physical objects. Importing such a device at that time cost more than 700,000 US dollars.
After returning to China in 1993, Lu Bingheng immediately shifted his research direction, leading four doctoral students into the laboratory. "As long as we work hard, Chinese people can do it too."
The start was very difficult. Importing a box of photosensitive resin cost over 100,000 US dollars, and a set of lasers also cost over 100,000 US dollars. Developing a set of equipment required at least 1 million yuan, but Lu Bingheng only had a few tens of thousands of yuan left over from other projects.
If they couldn't afford to buy, they would make it themselves. They collaborated with sister universities to build a laser for 30,000 yuan; and cooperated with the chemical engineering department to develop resin, reducing the cost per kilogram from 2,000 yuan for imports to 100 yuan. The software development, dynamic focusing mirror, and condenser lens were all completed by their own hands, and operating machine tools and making test pieces were common occurrences. Once, workers saw the test pieces processed by Lu Bingheng and marveled, "This level definitely reaches a fifth-grade worker."
During that period, students would privately grumble: "The direction Teacher Lu is working on is not done by anyone else in China. Will we be able to find jobs after graduation?"
The turning point came in 1995. At an advanced manufacturing technology conference, after the expert reports, it was time for free discussion. Lu Bingheng "jumped" onto the stage. After introducing the technology, he finally said: "This technology is very important; I hope to get national support."
Half a month later, news came that the inspection team would visit the school for investigation as soon as possible. Lu Bingheng was excited and worked overnight to make a model. By the day the inspection team arrived, the prototype they built already had scanning capabilities and could print small cubes.
A 2.5 million yuan national key science and technology project grant thus landed. "Opportunities are for those who are prepared," Lu Bingheng often said. "Do big things with whatever conditions you have, then find opportunities to gain support and get things done."
With funding support, they developed China's first prototype of a stereolithography resin laser rapid prototyping machine that very year. In 1997, they developed China's first commercial stereolithography rapid prototyping machine, and in the same year they founded Shaanxi Hengtong Intelligent Machine Co., Ltd.
To further reduce costs, Lu Bingheng proposed using ultraviolet lamps instead of lasers and developed the world's first UV rapid prototyping machine. The product was subsequently identified as a national key new product and quickly spread in the market; the first batch of customers included Changan Automobile and BYD.
At that time, imported equipment was quoted very high—Japan quoted 480,000 US dollars and the United States quoted 720,000 US dollars. Lu Bingheng's equipment only cost 1.5 million yuan, and many foreign companies came to discuss cooperation. A Japanese company once came to his door. Lu Bingheng said cooperation was possible, but it must be equal: "You act as our agent in Japan, and I'll act as yours in China." The other party left in frustration.
Afterwards, Lu Bingheng led his team to achieve full localization of the equipment, gradually reducing the price to 300,000–400,000 yuan, completely "suppressing" the American and Japanese equipment.
In 2000, Lu Bingheng's project "Several Key Technologies of Rapid Prototyping Manufacturing and Their Equipment" won the second prize of the National Science and Technology Progress Award. Subsequently, they launched 7 models and more than 10 specifications of equipment, including UV rapid prototyping machines and vacuum casting machines, as well as 9 models of supporting photosensitive resins, forming a complete rapid prototyping equipment system.
In 2005, the National Engineering Research Center for Rapid Manufacturing was approved for establishment, with Lu Bingheng serving as its director. They also developed laser rapid prototyping machines, metal spray rapid tooling manufacturing equipment, and other equipment, widely used in automobile manufacturing, aerospace, and biomedical fields.
In 2019, the National Additive Manufacturing Innovation Center (NICAM) was inaugurated in Xi'an. This is the only national-level innovation platform in the field of 3D printing, jointly established by Xi'an Jiaotong University, Beihang University, Northwestern Polytechnical University, Tsinghua University, Huazhong University of Science and Technology, and 13 enterprises. Lu Bingheng serves as the director of the National Additive Manufacturing Innovation Center. Under his leadership, the center has successively developed more than 10 major additive manufacturing equipment driven by lasers, electron beams, ion beams, electric arcs, and other technologies, applied for 387 national patents, and led or participated in the formulation of more than 40 industry standards.
In May 2020, the Long March 5B carrier rocket carried space 3D printing equipment developed by Lu Bingheng's team and collaborators, achieving China's first space 3D printing. This was also the first time internationally to conduct continuous fiber composite material 3D printing experiments in space.
Marching Toward "3D Printing Large Aircraft"
Lu Bingheng's aerospace dream continues.
On September 29, 2022, the C919 large passenger aircraft obtained its type certificate, and China had its first single-aisle trunk airliner able to enter route operations. At the same time, Lu Bingheng also launched the R&D plan for "3D printing large aircraft."
"Although the C919 has entered production, its production capacity is still seriously insufficient. There is a large gap between market demand and manufacturing capability. It is of great significance to open a new path for large aircraft manufacturing based on 3D printing," Lu Bingheng told China Science Daily.
Although C919 orders have exceeded 1,000, the actual delivery capacity urgently needs improvement. Using additive manufacturing to print large aircraft is the new technical route proposed by Lu Bingheng, and it is also a world first. He explained that this approach can significantly save raw material costs on the one hand; on the other hand, additive manufacturing has excellent flexibility and can quickly adapt to the production needs of different models. In the process of model conversion, there is no need for large-scale reconstruction of production lines, enabling seamless switching and efficient reuse of manufacturing capabilities across different platforms.
In addition, additive manufacturing can achieve integrated molding of large components, greatly simplifying the supply chain system. "Currently, manufacturing a large passenger aircraft internationally typically requires integrating more than 1,000 suppliers and supporting resources from over a hundred countries." In Lu Bingheng's view, enhancing the autonomous controllability of key components of large aircraft is of vital importance to the strategic security of China's aviation industry.
Lu Bingheng revealed the specific path: first, integrate the advantages of multiple processes to seek the optimal solution; second, systematically develop matching forming processes to ensure the quality and consistency of component manufacturing; the final and most critical step is to push the entire technical system through airworthiness certification.
Regarding this new track, Lu Bingheng has also heard doubts, but he firmly believes: "New things should allow for different opinions; doubts will help us do our work more perfectly."
Wang Lei, director of the Scientific Research Department of the National Additive Manufacturing Innovation Center, has followed Lu Bingheng since his doctoral studies in 2009. When asked about his impression of his mentor, he blurted out: "He is a very upright person." Although he also holds the identity of an entrepreneur, Lu Bingheng has always focused on industry development and national major needs when carrying out technical research and product development, never swayed by short-term interests.
Turning the National Additive Manufacturing Innovation Center into a "Whampoa Military Academy" for additive manufacturing is something Lu Bingheng has always insisted on. Whether someone comes to visit or he goes out to share new technologies and products under development, he holds nothing back.
Today, talents from Lu Bingheng's team have spread across aerospace, equipment manufacturing, medical, and other fields, and many have become backbone forces in education, research institutes, and enterprises.
To accelerate the realization of "3D printing large aircraft," Lu Bingheng is working harder than ever. Busy with travel, publicity, cooperation, and technical oversight, he handles tasks that could be delegated personally. "This is a new thing; I have to stand on the front line," Lu Bingheng said.
Lu Bingheng has had stents in his heart for 20 years, and the fifth was implanted in 2021. Worried about his health, his wife accompanies him on every business trip, making sure he takes his medicine on time. "He hopes to accomplish this for the country," his wife said.
"Tired?" Many people have asked him the same question.
"Tired," Lu Bingheng admitted. But he always holds a belief in his heart—a sentence he read in Marx's "Das Kapital" during junior high school: "There is no royal road to science, and only those who do not dread the fatiguing climb of its steep paths have a chance of gaining its luminous summits."
