Božidar Liščić †

He was known worldwide as the leading expert on quenching, which was the field where he contributed both ground-breaking scientific findings and most widely applied technological innovations for decades.
Born in 1929 in Croatia, he graduated in mechanical engineering and joined the machine-tools factory “Prvomajska”, starting as head of the heat treatment de-partment, and became the technical director of that factory at only 32 years of age. Subsequently, as a lecturer in heat treatment at the University of Zagreb, he established a well equipped heat treatment laboratory which soon became a leading heat treatment education and research facility.
At the time, there existed numerous empirical formulas and tables to predict the necessary quenching intensity to achive a certain hardness in a certain depth of cylindrical samples. However, they were insufficient to determine the necessary cooling characteristic, and to assess the resulting stresses and deformations. Liščić realized that this was because those techniques did not account for the variation of the heat flux during the different phases of quenching, and for the point of maximum heat transfer given by the particular quenching medium. So he developed a method to measure the temperature gradient near the surface of the workpiece, thus monitoring the heat flux continuously, through the whole temperature range of the quench.
In 1975 he received the PhD in material science from the University of Zagreb for his doctoral thesis “Depth of Hardening as Function of Steel Hardenability and of Quenching Parameters”. His open-mindedness and international connections showed as early as then: he performed part of the experiments at the Max-Planck Institut für Eisenforschung in Düsseldorf, Germany, and the other part in the laboratory in Zagreb, in collaboration with Swiss and American industrial companies. In 1978 he published his classical paper “Der Temperaturgradient auf der Oberfläche als Kenngrösse für die reale Abschreckintensität beim Härten“ (The Surface Temperature Gradient, a Key Indicator for the real Quenching In-tensity during Hardening) in Germany’s “Härterei-Technische Mitteilungen”.
His innovation was widely applied in industry when a special quench probe known as Liscic/Nanmac probe was developed for measuring and recording the quenching intensity in workshop conditions in cooperation with the American company NANMAC. Based on the results with this probe, the laboratory in Za-greb was commissioned to examine the quenching intensity of their polymer so-lutions by world-leading producers in USA, UK and Germany. Using the further developed IPSEN-Liscic sensor, the company IPSEN of Kleve, Germany, presented „Flux Control“ in 1995, a computer aided system for measuring the quenching intensity and calculation of the heat transfer coefficient with High Pressure Gas Quenching in vacuum furnaces.
Božidar Liščić was a full professor at the faculty for mechanical engineering in Za-greb from 1982 to 1999, and he was also always active on a global level. He was not only a visiting professor in Cincinnati, Ohio, USA, but he served also as UNDP (United Nations Development Programme) expert for heat treatment in as many as nine extended stays in Israel, India, Egypt, Turkey, Bangladesh, and Pakistan, to help those countries with the building of the respective industry and the train-ing of students.
In view of his strong dedication to the international community, in 1977 Božidar Liščić was invited by Urs Wyss, the first Secretary General of the then IFHT, to es-tablish an international committee on quenching, the Technical Committee „Sci-entific and Technological Aspects of Quenching“. Liščić was the chairman of the committee for the following 23 years. The outcome of that activity was, among others, the International Standard ISO-9950 “Industrial Quenching Oils, Deter-mination of Cooling Characteristics, Nickel-alloy Probe Test Method”. The ASTM Standards D 6200-97 for quench oils and D 6482-99 for aqueous polymer quenchants are also based on the work of the IFHTSE Quenching Committee, whose activities were joined with those of the ASTM Quenching Committee upon initiative of Božidar Liščić.
Under his leadership, the committee also planned and elaborated the handbook “Theory and Technology of Quenching“, edited by B. Liščić, H.M. Tensi, W. Luty (Springer Verlag 1992, 2nd edition with Lauralice C. F. Canale and George E. Tot-ten Taylor&Francis 2010). In two most influential classic handbooks, Liščić wrote the chapter on quenching: Eckstein, „Technologie der Wärmebehandlung von Stahl“ (1987), and Totten und Howes, „Steel Heat Treatment Handbook“ (Dekker 1997, 2nd edition Taylor&Francis 2007). He published more than 100 scientific papers.
Even after his retirement, he initiated IFHTSE’s Liquid Quenching Database (LQDB) and was an active participant in the Quenching Research Centre (QRC) of the University of Zagreb, which brings together local scientists with world-known experts from institutes and industry, in development and education of theory and technology of quenching.
His incessant commitment to international cooperation culminated in his service as IFHTSE President 2004-2005. He was always willing if not eager to share his findings and experiences with colleagues, and discuss them vividly and passion-ately, but always in a most cooperative and constructive spirit. He was open to answer questions and give advice, and particularly active in the education of stu-dents and young researchers and professionals. His many invited keynote lec-tures were the highlight of international conferences in Australia, Austria, Ger-many (given in impeccable German), Hungary, India, Japan, Ukraine, Slovenia, and USA. With deep gratitude for this service to the Federation he was appoint-ed IFHTSE Fellow in 2011, “In recognition of his numerous past and ongoing de-velopments in the quenching and heat treatment of steels and for his tireless support of global knowledge transfer for the global heat treatment community”.
He was a member and Fellow of ASM (USA), where he co-founded the Heat Treatment Society, and of AWT (Germany), who bestowed him with the Adolf-Martens-Medal, their highest award.
Few persons were and are as truly globally present, and such a strong node in the network of our community as he was. We are grateful to have enjoyed the company of, and cooperation with, this cosmopolitan gentleman.