John N. DuPont, PhD, is the R.D. Stout Distinguished Professor in the Materials Science and Engineering Department at Lehigh University and Associate Director of the Energy Research Center. A Fellow of both the American Welding Society and ASM International, Dr. DuPont has won numerous awards for his research and teaching, including the Charles H. Jennings Memorial Award., the William Spraragen Memorial Award, the Masubuchi Award., the Lehigh Teaching Excellence Award, and the McKay-Helm award. He and his students have published over 200 articles in the area of solidification, high-temperature corrosion, and welding metallurgy. John C. Lippold, PhD, is a Professor in the Welding Engineering Program and leader of the Welding and Joining Metallurgy Group at The Ohio State University. A Fellow of both the American Welding Society and ASM International, Dr. Lippold has received numerous awards for his research and teaching, including the Charles H. Jennings Memorial Award, the William Spraragen Memorial Award, the McKay-Helm Award, the James F. Lincoln Gold Medal, the Comfort A. Adams Lecture Award, the Plummer Memorial Education Lecture Award, and the IIW Jaeger Lecture Award. Together with his students and colleagues, he has published over 250 articles on welding metallurgy and weldability of structural materials. Samuel D. Kiser is Director of Technology for the Special Metals Welding Products Co., formerly INCO.  He is a professional welding engineer, a Fellow of the American Welding Society, and holds more than ten patents for nickel alloy welding products. Sam is the recipient of the A.F. Davis Silver Medal and the Samuel Wylie Miller Memorial Medal Awards, and has published more than eighty articles and lectured extensively at AWS meetings to audiences around the world.