Obituary Prof. Dr. Ir. Sieb Radelaar by M2i Senior Scientific Advisor Rob Boom

S. Radelaar, foto KNAW

S. Radelaar, foto KNAWI (Rob Boom) met Sieb Radelaar  for the first time in 1970 in the Research Committee Metals FOM-TNO where he was one of the staff metallurgists from the RU Groningen. As PhD student I represented the metal physicists employed by the Foundation of Fundamental Research in Matter (FOM)  stationed at the Natuurkundig Laboratorium of the University of Amsterdam. My promoter was prof. Andries Miedema, who became director of Philips Natuurkundig Laboratorium in Eindhoven,  just after accepting me as his PhD student. In this Committee the two worlds of metallurgists, thinking in dislocations and mechanical properties of structural metals and alloys,  encountered the world of metal physicists, thinking in electrons and transport properties of functional metals and alloys. In his career prof. Radelaar played important roles in both fields.

In 1991 prof. Radelaar and prof. Van den Beukel acted as promoters for the honorary doctor degree granted to Andries Miedema by Delft University of Technology. This was one of the occasions where  Radelaar expressed his conviction that metal physicists and metallurgists should closely collaborate to improve the understanding and application of metals in society. The Miedema model of cohesion in metals, from which the alloying behaviour of virtually all metals could be predicted for the first time ever, was a clear example of such a breakthrough in metals understanding directly applicable in practice.  Prof. Frank de Boer from the University of Amsterdam and myself, at the time working in the metals industry (Hoogovens R&D), functioned as paranymfs at this honorary doctor event. For several years Frank de Boer and I have been working at TU Delft on extension of the Miedema model which over the last almost fifty years has been proven to be highly useful.

Twenty years ago the Dutch government introduced Top Technology Institutes as instruments to bring industry and academia together, which should result in a promotion of Dutch economy. One of the initiatives that succeeded in a harsh competition was by the Dutch metals industry in combination with leading researchers in the metals field. The Netherlands Institute for Metals Research NIMR was founded. The Board of NIMR attracted prof. Sieb Radelaar as Scientific Director and General Manager which appeared to be an excellent decision. In a surprisingly short period of time NIMR was up and running and managed to cash in the maximum amount of subsidy from the Ministry of Economic Affairs. On initiative of Radelaar NIMR, in collaboration with the Department of Materials Science and Engineering, established a chair on Primary Metals Production at TU Delft in 1999. I was appointed on this chair and from that moment onwards the collaboration with Radelaar was highly intensified. In particular the meetings of the Scientific Programme Council which I chaired were memorable. Intense debates about scientific project proposals, in a collegial atmosphere with respect for each other, spangled with humour and organised in a top restaurant were typical for the way NIMR was managed by Radelaar. Also the discussions with the members of the Scientific Advisory Board (SAB), all esteemed professors in metals research from all over the world, were of a high level. The suggestions by the SAB about direction and type of research needed to improve the understanding of metals were welcomed by Radelaar and used to improve the programme. With the Chairman of the SAB, prof. Frans Spaepen form Harvard, he shared his bird watching (ornithology) hobby. Radelaar also introduced collaboration with FOM in an industrial partnership programme, bringing fundamental and application research together.

In 2002 Radelaar suffered from a serious illness which needed immediate medical action. For a period of 6 months I acted as  interim director, keeping in close contact with him. The prospects of cure were not good at that time, but fortunately and thanks to intense medical treatment, a good condition and a strong will, Radelaar has been granted 15 years more. We could organise a proper farewell symposium for him in 2004 when he reached the retirement age.

We have good memories from the leadership of Sieb Radelaar. On 25^th April a delegation of former members of NIMR and employees of NIMR Office have shown their respect at his farewell. We wish his wife, children and grandchildren the strength to carry this loss.

Rob Boom

M2i Senior Scientific Advisor