In recognition of his outstanding achievements in tribology and in particular for his endeavours to link Tribochemistry and Tribomechanics.
Professor Toshio Sakurai was born in 1915. He graduated in Applied Chemistry at the Tokyo Institute of Technology (TIT) where in 1947, he became a Research Assistant in its Department of Chemical Engineering and an Associate Professor in 1956. He was appointed a full Professor in 1964 and on his retirement in 1976, Professor Emeritus. Until 1983 he was also professor of the Tokai University.
Even at an early stage of his career, Professor Sakurai was keenly interested in mechano-chemical phenomena in tribology. His application of analytical technology to studies of surface films relating to additives, led to a number of valuable findings, which facilitated the understanding of the molecular behaviour in additives in lubricating oils.
Professor Sakurai’s work on viscous oil films led to the concept of a critical contact pressure for operating limits of viscous films of base stocks, and to his discovery in elastohydrodynamic lubrication, findings which contributed greatly to later research in these fields.
Arguably Professor Sakurai’s most important work was concerned with the elucidation of the dynamic operating mechanisms of extreme pressure agents. He pioneered the concepts of “reaction kinematics” and of “tribo-chemical reaction”, which demonstrated the importance in tribology of the chemical aspects. He revealed the differences in the reactivity of extreme pressure agents under varying operating conditions, atmospheres and internal stresses, and he succeeded in developing molybdenum-dialkyl-dithiocarbomate, one of the most effective friction modifiers. He also introduced the new technology of extreme pressure additives that form solid lubricant films in-situ.
Throughout his distinguished career, Professor Sakurai endeavoured to bridge the boundaries between chemistry and mechanical sciences. He is an undisputed and internationally recognised authority in the field of tribo-chemistry and his achievements are known and acknowledged worldwide.
Professor Sakurai’s outstanding work was, however, not limited to his research. In education and training, especially at the Tokyo Institute of Technology, he was responsible for the intellectual formation of graduates in tribology. His great teaching skill, knowledge and the genuine warm relationship with his students and graduates, led to many of them, after graduation, pursuing careers in the field of tribology at universities, petroleum, chemical, bearing, automotive and heavy industries in Japan – a true testimony to his teaching. A significant number of today’s authorities in tribological subjects in Japan are Professor Sakurai’s past students. Professor Sakurai also introduced the science of tribology to sales engineers of lubricants, many of whom became tribologists.
In the area of Technology Transfer through publications and Learned Societies activities, Professor Sakurai has played a leading role. Not only has he to his credit six books and over 120 papers, but also, together with Professor Norimune Soda, he was primarily responsible for the formation in 1950 of the Japan Society of Lubrication Engineers (JSLE) which he served for eight years as Director, for a further six years as a Vice-President and as President from 1971 to 1974. Professor Sakurai has also been President of the Japan Petroleum Institute and a member of several Government Scientific and Technical Committees.
As might be expected, Professor Sakurai has been the recipient of many awards and honours. Amongst these were Honorary Memberships of the Japan Society for Lubrication Engineers (1975), of Japan Petroleum Institute (1978) and of the American Society of Lubrication Engineers (1986). He received the JPI Prize of the Japan Petroleum Institute in 1962, the American Society of Mechanical Engineers Centennial Medallion in 1980 and the American Society of Lubrication Engineers National Award in 1986. For his contribution to Japanese industry, which is widely believed to have significantly contributed to the attainment of high reliability of Japanese machinery, the Japanese Government honoured him with the award of the Blue Ribbon Medal in 1986.
An outstanding Tribologist, internationally acknowledged to be one of the world’s leaders in his field, Professor Toshio Sakurai is indeed a worthy recipient of Tribology’s highest honour, the Tribology Gold Medal for 1990.