In Germany:  Study  |  Results  |  Funds  |  Procedure  |  What I learnt  |  Others

I studied in the Institut of Metalforming, Technical University Bergakademie Freiberg from October 1990 to September 1995, for Ph.D. TU Bergakademie Freiberg is the oldest school in the world in the area of metallurgy and mining.

Studied Areas. My Ph.D. study was on the computer simulation of a metal forming process (steel hot rolling for sections) with help of finite element method (FEM). During the study I simulated both thermal and mechanical parameters in flat rolling, angle steel rolling, H-beam rolling, and slab castrolling with liquid core. In particular, I made excellent validation for the simulation, for not only the global parameters (width, force, torque, etc.), but also, particularly, the local metal flow (local spread, local reduction, etc.). The local metal flow is very hard to measure for sections in complicated shape. I also established and validated a simplified FEM model for rolling process simulation, which takes only 5% of the computing time required by regular FEM model. Such a simplified model is very suitable for industry to study local parameters, such as temperature and microstructure during forming and cooling, and to integrated FEM analysis into roll pass design software and Level 2 system. My research projects gave birth to a new Unix laboratory, in which I worked for five years. The five years of stay with the Unix laboratory, from its startup to the later operation, gave me good opportunity to gain experience on Unix.

Research Results. The results of my work were highly rated by researchers (including very influential scholars like R. Kopp, O. Pawelski and A. Hensel in Germany) and industry (e.g. Mannesmann Demag in Germany, Danieli in Italy). Pawelski, the director of the Max-Planck Institute for Steel Research, was the first person that highly rated my results, in the early 1993; at the time my primary results (angle steel rolling process modeling and validation) was not yet received. R. Kopp, the institute director of the IBF of the RWTH Aachen, commended that he liked my simplified FEM model very much. The simplified FEM model was showed to the world very late, in 1995. Both Kopp and Pawelski were internationally recognized figure. For example, Kopp was one of the key person to approve the DFG (German Research Association) grant. He was also the technical adviser for then SMS Schloeman Siemag. For this reason, after my graduation my former institute was easily approved for an one year grant to study my simplified FEM model, and my former academic advisor, Prof. Hensel (who is also a well-known researcher), called me later and claimed that the result was very satisfactory. Many people in the metal forming industry knows that in Freiberg there was a Li who did a good job on FEM simulation for the rolling process. During my Ph.D. study, I was frequently visited by Mannesmann Demag, and was invited by Danieli to Italy for three times. Mr. Teichert, who was in charge of the three rolling mill departments of then Mannesmann Damag (now SMS Demag), told me that right after my first results were published, Mannesmann Demag immediately introduced the same software (code MARC) I worked with and began to apply my concept. Before my work, the FEM simulation for the shape rolling process was considered to be a theoretical research and was not really used in the industry for the shape rolling. After my results were published, the world, led by the top companies such as Mannesmann Demag, SMS and Danieli, etc., put FEM into real application. This would reduce 70% of the rolling tests because, with combination with FEM, only 30% of the total tests are still needed, primarily to verify the simulation results. During my Ph.D. study I was also arranged by the institute to direct a Master (Dip.-Ing. in Germany) student and several other research students. In July 4, 1995, over 70 colleagues, from industry, universities and research institutes, attended my Ph.D. defense. In the evening after the defense, over 50 people celebrated my successful Ph.D. defense in a restaurant. Before the Ph.D. defense I already received the official job offer from the US steel technology company Morgan. In 1996, half a year after I left for USA, a book of mine was published in Germany (ISBN 3-86012-029-8) on FEM simulation of steel rolling. Eight years after I left the institute, my name and results were still presented in the Institute's web site, and I noticed that I was the only graduate or student, whose name appeared in the research section of the site. Though after eight years the website was redesigned, the picture in the header page was still the angle steel rolling simulated by FEM; that was my Ph.D. project.
 

In Germany:  Study  |  Results  |  Funds  |  Procedure  |  What I learnt  |  Others

Research Funds and Environment. Three months after I entered Germany, I was awarded with scholarship from the DAAD (the German Academic Exchange Service). One year later, my research project was awarded with funds from DFG (Deutscher Forschungsgemeinschaft, i.e. German Research Association, the government organization to finance research projects). The project came with two full-time positions, though I was the only one who worked on it (After the other research fellow left I convinced the institute that I could complete the project myself). Totally about 500,000 DM ($350,000) was received from the DFG. Besides various experimental and labor costs for the research project, the funds were also used to build the new Unix laboratory mentioned above (over 100,000 US Dollar was spent in the first stage to buy hardware and FEM code MARC). This provided my project with the state-of-the-art software and hardware, and made it possible for my Ph.D. study to reach the high technical level. Our research team, led by Prof. Dr. A. Hensel, also had quite a number of other industry projects with rich funds. One of them, for example, was a million-DM project (0.66 million US Dollar) from then Mannesmann Demag, the biggest steel mill technology vendor in the world. The institute was the primary research partner of Mannesmann Demag.

Ph.D. Procedure. It seems that it takes longer time in Germany to get a Ph.D. than in USA or China. In TU Bergakademie, even after all the research stages have been completed, it still takes about one year to write Ph.D. thesis (eight months for a native German speaker). Required literature evaluation section, which should reach a high technical level and cover a broad range of topics, normally takes over 50% of the total time of thesis composition. After the thesis is handed in to the university, it still takes academic advisors 3 - 5 months to check the thesis. In the mean time, Ph.D. Candidates must successfully pass an exam called Rigorosum before open defense. So-called Rigorosum is an oral examination against a team of professors in the primary major (Metal Forming for me), and a secondary major which must not be directly related to the primary major, each for several hours. I selected Industry Management as my secondary major. The institute recommended me to pick the Computer Science since I was considered as the computer guy in the institute.
 

In Germany:  Study  |  Results  |  Funds  |  Procedure  |  What I learnt  |  Others

What I have learnt. In these five years in Germany, I really received so much. In addition to the knowledge I gained, there are lots of more important things. The culture I learned and some special skills I received are the two things I want to mention here as example. I started to have interest in my major during my study in Germany, even though I hated it during during my undergraduate study. Most German people, if not all, love what they are doing. In a tombstone it wrote: "Here lies a miner ...". I have learnt lots of good ways to handle things, particularly from my academic advisor, Prof. Dr. Hensel. In the last stage of my study, Prof. Hensel once spent three full days with me to recompose the text of my Ph.D. thesis (though the wording in the text had been improved by my co-work and friend Dr. Goldhahn for many times). Prof. Hensel wanted to push the thesis to a higher level than average because the university planed to publish it as a book. I realized this was a great opportunity to learn from one of the world's most successful scholars. While he tried to get deep understanding on how I carried out computer simulation, I closely observed how he studied the problems, how he handled what he knew and what he was not clear, and particularly, how he wrote a book with the things he knew well and the things he wasn't very sure. This is a person who became a full professor and institute director at mere 39 years old in Germany, who published three books and several hundreds of papers, and served as the pro-rector of the university and the technical editor of a famous magazine. He even gave up the road to high rank official (government minister) and chose to be an academic.

Others. In those years I had also pretty good luck. Nearly one year after I went to Germany I was arranged to direct a Master student. At the same time another Ph.D. candidate (from Zhejiang University, also selected by China, same type as me) who went to Germany one year earlier than I and was also doing steel rolling process simulation, was just working on his own Master thesis. After I accepted the job offer from Morgan, I left him a list of interview invitations sent to me (two of which were from USA), but he failed to catch any of them. The primary problem for those Germany-trained Chinese were the lack of English-speaking skill after years of working in German language; some of them managed to come to USA to work or study in the universities but very few could go to companies directly. For a Chinese, the German and English are similar and are fighting against each other; it is very hard to speak both well. This was also a challenge for me as I came to USA for interview, in English, after seven years of using and speaking German. However, I tried to maintain my English-speaking skills during my stay in Germany. Even before I went to Germany, I already spoke better English then the rest of the 10 students to be sent to Germany by China.

It is interesting, that Danieli had decided to hire me three months before Morgan contacted me, and I did have interest to work for Danieli. However, inside Danieli the technical director (Attilio Sachi, Morgardshammar) and sales VP (Franco Alzetta) had different opinion on where to put me. Its technical department wanted my research result, and its sales division needed a liaison between China and Italy, and I had interest for both. Italian visa needed a month to get, and US visa only a day. Morgan, however, fully utilized this time gap to finish my hiring process: from visa application to US interview and job offer. For a while, Morgan's HR VP called me every day at 9am (3pm in Germany) to make sure everything was OK in my visa application. I was extremely busy preparing my Rigorosum and Ph.D. defense and revising my thesis to be published as book. Years passed by, I often still not sure whether it was a wise decision to work for Morgan. One thing is clear, that it's better to work in USA than in Italy, because I don't speak Italian.
 

In Germany:  Study  |  Results  |  Funds  |  Procedure  |  What I learnt  |  Others

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