Li Yiyi




Li Yiyi, female, an expert of metallurgy and material, was born in Beijing in 1933 into a family which came from Suzhou, Jiangsu. She graduated from the Department of Metallurgy, Beijing Institute of Iron and Steel Technology in 1957. Professor Li is now a member of the Chinese Academy of Sciences (CAS) and director of the Institute of Metal Research, CAS.
Professor Li was the first to propose a technical route for high-pressure hydrogen charging in a hot gaseous environment, and to have set up a comprehensive system for research of cryogenic materials and high-pressure hydrogen resistant materials in China. Her creative and systematic accomplishments in the diffusion and penetration behaviour of hydrogen in metals, transformation of alloys under cryogenic and micro-gravity conditions, and in the development of new steel series have advanced Chinas research to a level similar to developed countries in these areas.
In the early 1970s, Professor Li developed high-strength nonmagnetic stainless steels for use at ultra low temperature, on the superconducting magnet frame of controlled fusion reactors. She measured the comprehensive mechanical and physical properties of cryogenic steels between 4.2 K and 300 K. She and her co-workers were the first to measure the Fe-Mn-Al phase diagram and to propose a phase identification method. Professor Li was regarded as the first to have experimentally observed the pole mechanism of stacking fault superimposition during martensitic nucleation and growth, using a low temperature electron microscope. These basic researches enabled her to successfully develop 9 series of steels. The achievements have won her many state and ministry level awards, including the CAS First Class Award for the Advancement of Science and Technology (three times) and the Second Class State Award for the Advancement of Science and Technology (three times). She has supervised more than 20 students who obtained Ph.D. and Masters degrees, and is the author of more than 150 scientific publications. Professor Li attends international academic conferences frequently, and was invited as session chairs or gave invited lectures on 8  occasions.
In 1990 Professor Li was appointed director of the Institute of Metal Research, CAS. Under her leadership, the institute has won more than a dozen state key projects with more than a million yuan investment, an representative example being the“Low Segregation Alloy Engineering”. The institutes basic research has won international recognition, and applied research is being linked with the market through the newly-established National Engineering Research Centre, and North China R&D Centre for Advanced Materials.
In 1983 Professor Li was elected an executive member of the International Society for Cryogenic Materials, in 1986, a vice chair of the board of directors of the Chinese Society for Metals, and in 1990, a vice president of the executive board of the Chinese Materials Research Society. In May 1997 she was elected president of the Science and Technology Associaton of Liaoning Province.