Arthur D. Pelton is Professor Emeritus in the Department of Chemical Engineering and co-director of the Center for Computational Thermochemistry at the Ecole Polytechnique in Montreal, Quebec, Canada.Dr. Pelton received his undergraduate and graduate degrees from the Dep’t. of Metallurgy and Materials Science at the University of Toronto (PhD in 1970). Following post-doctoral studies at the Technical University in Clausthal, Germany and at MIT, he joined the faculty of the Ecole Polytechnique in the Dep’t. of Materials Engineering in 1973. Dr. Pelton has co-authored over 250 technical papers and 16 book chapters, including the chapter on Phase Diagrams in “Physical Metallurgy 3rd and 4th editions (Elsevier), and on Thermodynamics and Phase Diagrams in the 5th edition. He is a Fellow of the Royal Society of Canada, the Canadian Academy of Engineering and the American Society for Materials. He is a recipient of the AIME Extraction & Processing Distinguished Lecturer Award, the Gibbs Triangle Award of the international Calphad (Calculation of Phase Diagrams) group, the J. Willard Gibbs Phase Equilibria Award of ASM and the Hume-Rothery Prize (for contributions to the study of phase equilibria) of the Institute of Materials (UK) as well as other national and international awards. His primary field of interest is chemical thermodynamics. He is co-founder of the FactSage thermodynamic database computing system which has approximately 900 users in 45 countries.