Mathematical Modelling of Weld Phenomena 5 PDF

INTRODUCTION

Quantitative analysis is the essence of science and increasingly of technology. The fifth International Seminar on the 'Numerical Analysis of Weld ability' was held in September 1999 at its usual location in Schloss Seggau near Graz, Austria. This biennial meeting was organised by the Institute of Materials Science and Welding Technology of the Technical University ofGraz and the working group 'Mathematical Modelling of Weld Phenomena' of Commission IX of the International Institute of Welding (IIW).

Graz is in 2003 to become the Cultural Capital of Europe, but our aim in choosing this location is to ensure international participation at an affordable cost, in relaxed isolation conducive to the free flow of ideas. This region of Sty ria is famous for its welcoming spirit and generosity, particularly towards scientists and technologists.

The academic aim of these meetings has always been to publish authoritative, wellwritten, refereed and edited articles which are written in sufficient depth to enable the ready reproduction of the work and to serve as teaching material. To this end, it is nice to note that the four sets of past proceedings Mathematical Modelling of Weld Phenomena, H. Cerjak and K. E. Easterling eds; Mathematical Modelling of Weld Phenomena 2-4, H. Cerjak and H. K. D. H. Bhadeshia eds, are being exploited if citations are anything to go by.

It is possible to chart the progress of the subject since 1991 when the first of these meetings was held. From an industrial point of view, there are commercial products and processes which have benefited from the work, some examples of which can be found in the present proceedings. The new science is also exciting. For example, the first ever model of the evolution of grain structure across the whole of the welded joint; a novel model for the friction welding of cast irons. We now know for sure that it is convection rather than diffusion which contributes most to vaporisation during the laser welding of aluminium alloys; this is of importance in explaining the loss of elements from the fusion zone. We understand better how bubbles behave in a microgravity environment.

Mathematical 'tricks' have been discovered which in combination with insight enables complex phenomena to be described using linear algebra. These are just a few examples of the vitality of the subject and indeed, how it is being assimilated by enlightened industry. It is no wonder that the subject continues to attract the very best of scientists and engineers.

We would like to thank the local organisers in Graz who made all the visitors so welcome, and who are now preparing for the 6th International Seminar to be held 1-3 October 2001. A special thanks to Bernhard Schaffernak for his incredible hard-work in making the conference and its publication a success. Sadly, 'Bernie' will be leaving the University to undertake an important technical assignment with the Styrian Government; we congratulate him on this appointment. We greatly appreciate the work of Peter Danckwerts and his team at the Institute of Materials, who are responsible for the high production quality of this publication.

Once again, we would like to express our sincere gratitude to all those who have participated in this interesting and challenging project by putting their ideas and results down on paper.

Edited by: H. Cerjak, H.K.D.H. Bhadeshia