Xie Jianxin, 65 years old, has his hair dyed gray and gray by the years. He is still full of energy, and when the children ask questions about the material, he will answer them patiently with interest.
In 1978, Xie Jianxin was admitted to the then Central South Institute of Mining and Metallurgy (the predecessor of the current Central South University) majoring in metal pressure processing, and since then he has been associated with metal materials. In 1991, he received his Ph.D. in Engineering from the Department of Materials Processing, Faculty of Engineering, Tohoku University, Japan. In 1995, he returned to China to the University of Science and Technology Beijing as a professor.
Xie Jianxin's sensitivity to materials exceeds that of his time. In 1998, the price of copper was still relatively low, but Xie Jianxin predicted that copper resources would be very much needed for national construction in the future, but copper resources were scarce, so the price of copper would rise sharply. The mainland is a country rich in aluminum resources, so he proposed a new idea of direct forming of copper-aluminum composite continuous casting.
His judgment turned out to be correct. The mainland is the world's largest consumer of copper, accounting for more than one-third of total global demand. The shortage of copper resources has become a serious constraint on the economic development of the mainland.
Xie Jianxin studied this topic for 15 years, and finally successfully realized copper-aluminum composite continuous casting. The continuous casting process of the enterprise takes at least three days and three nights, and if the stability control is not good, the product quality will be reduced. Xie Jianxin always insisted on doing it himself, leading the team into the industrialization enterprise for technical guidance, participating in equipment installation and commissioning and process test research, and often working on the site for a month. He often said: "Those who engage in science cannot stay in the office every day, but must go to the front line of engineering to solve practical problems." ”
His team has also been well received by the company: "This is a team with engineering practice skills!"
In the end, large-scale industrial production of copper-aluminum composite materials was realized, and the material cost was reduced by 30%-50% compared with pure copper products, which greatly alleviated the shortage of copper resources in the mainland.
Xie Jianxin attaches great importance to the professional learning and scientific research ability improvement of each student, and all the research topics of doctoral and master's students he leads are from national tasks, enterprise needs or discipline frontiers.
From topic selection to mid-term report to graduation defense, Xie Jianxin listened carefully to every project progress report of students, corrected the details of the experiment, and personally revised each report and paper, and revised a journal paper three or five times at least, and more than ten times. Every revision is a careful word, even a punctuation mistake is corrected clearly, more carefully than the students themselves. By the time the students graduate, the students in the research group will have accumulated a thick pile of manuscripts that have been carefully corrected by him.
In 2020, in the face of the sudden new crown epidemic, many graduate students could only carry out literature research at home. Xie Jianxin wrote the "Guide to Writing the Thesis Proposal Report for 2019 Master's Degree Students" to help students pass the first hurdle of scientific research of "Thesis Proposal Report".
The students all know that as long as there is nothing else, Xie Jianxin is in the laboratory every day. Early in the morning or late at night, you may run into him in the laboratory. He is often the last person to leave the lab, which makes many students feel ashamed.
Xie Jianxin often said that he did not think that he was talented, but that he was willing to put in it. With a diligent attitude, rigorous style, and teaching by word and deed, he has cultivated a large number of outstanding talents with solid basic theories and can solve practical problems in scientific research and production, and most of his students have become the leaders and technical backbones of scientific research, teaching, and production in colleges and universities, scientific research institutions and enterprises.
"At our age, we don't have any dreams, and it's better to do more practical things than anything else. Xie Jianxin said.
On December 18, 2023, at the site of the "Academicians and Experts Talk about Science" activity in Beijing Railway No. 2 Middle School, Xie Jianxin, former vice president of the University of Science and Technology Beijing and academician of the Chinese Academy of Engineering, was giving a speech. Photo by Beijing News reporter Wang Zicheng
dialogue
Beijing News: Why did you choose materials science?
Xie Jianxin: In our era, everything from university entrance examination to employment was distributed. When I was admitted to university, I was admitted to the materials major. Although I didn't know about this major at the time, I felt that for anyone, they should "learn a line, love a line, and drill a line".
People will encounter a lot of coincidences in their lives, you may want to study computer science the most, but when you are assigned to materials science in college, how to fall in love with and study this industry at this time, I think it is more important than other things.
Beijing News: What motivates you to keep exploring?
Xie Jianxin: When I was engaged in the professional research of materials science, I received many tasks, which were completed with quality and quantity, and I naturally gradually fell in love with this industry. It's not a burden, it's a hobby for me.
Beijing News: How long did it take you to develop the copper-aluminum continuous casting composite method?
Xie Jianxin: I spent more than ten years on that project. We often say "ten years to sharpen a sword", sometimes an idea comes up with a simple idea, but it doesn't work like that. It often takes ten years for an achievement to go from laboratory research to industrial production to the shelf.
Beijing News: What is the advance of the copper-aluminum continuous casting composite method compared with the previous method?
Xie Jianxin: In copper-aluminum composite materials, copper accounts for 20%-30%, and aluminum accounts for more than 70%. Compared with the previous 100% copper, this can greatly save costs, and can also obtain conductivity that is basically close to copper, which greatly alleviates the pressure on the mainland's demand for copper resources.
The traditional copper-aluminum composite method is to wrap a layer of copper skin on the outside of the aluminum rod and weld the copper skin together, like making dumplings, but the quality of copper-aluminum interface bonding is poor. The method I invented was to continuously cast the copper tube, and at the same time continuously fill the copper tube with molten aluminum, and prepare a high-quality copper-aluminum composite billet in one step. There is diffusion between liquid aluminum and copper, and the bond strength of the two will be greater.
Beijing News: What are the difficulties in this method?
Xie Jianxin: Direct contact between liquid aluminum and copper tends to have a violent and rapid reaction to form intermetallic compounds. How to control the interface of the reaction between the two metals to achieve metallurgical bonding at the interface, while avoiding the formation of brittle alloy compounds, resulting in the separation of copper and aluminum during subsequent processing.
Beijing News: What are the fields in which the results of the copper-aluminum continuous casting composite method are applied?
Xie Jianxin: At present, enterprises can already use copper and aluminum continuous casting to produce composite products such as flat bars, flat wires and round wires, we have developed new processes and complete sets of technologies for the short-process production of composite products such as electric flat bars and electromagnetic flat wires, developed a variety of key equipment, and achieved large-scale production, and the products have been widely and mass-applied in aerospace, military equipment, high-speed rail, new energy and other fields. The project took nearly 15 years. This achievement won the second prize of the 2014 National Technological Invention Award.
Beijing News: What research and projects have you been doing in recent years?
Xie Jianxin: In order to cope with the competition situation of materials science and technology in the context of a new round of global scientific and technological revolution and industrial transformation, and accelerate the improvement of the mainland's material science and technology innovation capabilities and industrial transformation, I led the joint 34 academicians of the Chinese Academy of Sciences and the Chinese Academy of Sciences in the field of materials in the mainland to submit the "Proposal on the Formulation of the National Materials Genome Engineering Research Plan" to the national leaders, which was highly valued by the leading comrades of the State Council and directly promoted the formulation of the "National Materials Genome Engineering Plan (2021-2035)".
With the University of Science and Technology Beijing as the supporting unit, Beijing Information Science and Technology University, the Institute of Physics of the Chinese Academy of Sciences, and the China Iron and Steel Research Institute Science and Technology Group as the co-construction units, we applied for the "Beijing Advanced Innovation Center for Materials Genetic Engineering", which was approved in October 2017. The center has gathered more than 150 high-level innovative talents in the field of materials at home and abroad, including 24 academicians at home and abroad, including Professor G. Olson of the Massachusetts Institute of Technology and Professor Shuichi Iwata of the University of Tokyo, and has made important contributions to promoting the high-level development of materials discipline and interdisciplinary development of science and technology Beijing, and driving the development of computer and artificial intelligence disciplines.
Big Data, Artificial Intelligence, At present, I am leading the team to actively open up cutting-edge research directions, and have made innovations in three aspects in the direction of data-driven machine learning, which are among the best in China and have had a great impact in the world: invented the machine learning alloy composition method oriented to performance requirements, which broke through the problem of designing alloy composition according to performance requirements, broke through the problem of machine learning method analyzing the influence of alloy elements on performance, established a method for designing alloy composition according to the influence of elements, and established a machine learning-assisted rapid design of alloy preparation and processing process parameters, which can reduce the experimental research workload by an order of magnitudeto subversively improve research efficiency.
Xie Jianxin wrote a message. Photo courtesy of the interviewee
Q&A
What do you think academicians do popular science?
If academicians have the opportunity to have time, it is still very meaningful to participate in some popular science activities. Elementary and junior high school students don't usually have access to academicians, so I think it's good if they can see the ways and means of academicians doing research through this kind of activity.
What are the key qualities a scientist should possess?
The quality of a scientist is not exactly the same, but I think the most important thing for a scientist is the ability to observe and think.
We engineering students have to do a lot of experiments, and it is very important to observe life and the experimental process. People often say that scientists are doing science, and the word "learning" does not mean asking others, but thinking about the connections between various things.
What is the importance of science to the nation and the nation?
Science is the common wealth of mankind, but if science is to be transformed into productive forces, then science has strong national boundaries and national attributes. This can be understood that when New China was first founded, why so many scientists broke through many obstacles and returned to China to do scientific research, because those scientists had a strong sense of nationality and mission.
How to make children fall in love with science?
It is very difficult to make children fall in love with science, because it involves many aspects of family, society and school. I think it is a way to let children have more exposure to science lectures, and it is also important for school teachers to have a relatively high level of scientific literacy.
If the math, physics, and chemistry teachers could combine what they are talking about with science, and tell the children what the discovery of the scientific invention they are talking about means for that era, I think the children will be more interested.
The teacher may only use one sentence to bring it to the students, and the experiment I did today is not only to learn knowledge, but also to understand the historical context of the development of science and technology. Therefore, I think how to improve the scientific and cultural literacy of teachers is also very important.
Beijing News reporter Guo Yimeng, editor Liu Qian, proofreader, Zhao Lin, Yang Xuli