New Faculty on Campus

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COLLEGE OF ENGINEERING
Department of Materials Science and Engineering

STEPHEN MASHL
Stephen Mashl joins the faculty as research professor. He comes to Michigan Tech from Bodycote plc. He holds a PhD, MS and BS in Metallurgical Engineering from Michigan Technological University. Mashl is a member of the Metal Powder Industries Federation, the American Society for Metals, The Minerals, Metals and Materials Society and the United States Department of Energy-Materials Innovation Impact Team.

JOSHUA PEARCE
Joshua Pearce joins the faculty as associate professor. He comes to Michigan Tech from Queen’s University. He holds a PhD in Materials Science Engineering and a BS in Physics and Chemistry from Pennsylvania State University. Pearce has served on the Board of Advisors for AEPAY Global Energy and Mana Mushrooms LLC. He has also served on the board of directors for Hearthmakers Energy Cooperative.

Understanding Segregation Defect Formation in Remelting Processing of High Temperature Alloys

Friday, October 21, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Matthew John M. Krane
Associate Professor of Materials Engineering Purdue Center for Metal Casting Research Purdue University, West Lafayette, Indiana

Abstract

Remelting processes provide routes to large ingots of specialty metals which have relatively few defects. However, past certain limits on size of the ingots and speed of these processes several types of segregation related defects begin to occur. The heat, mass and momentum transfer and electromagnetics present during electroslag and vacuum arc remelting (ESR and VAR) are modeled and sump profiles and macrosegregation patterns are predicted. These results are studied as functions of process parameters and ingot geometry. During ESR of nickel-based superalloys, a maximum in macrosegregation is found as a function of filling velocity in the flow regime dominated by buoyancy. During VAR of titanium alloys, DC current levels are generally much higher than the AC current in ESR, so the sump flow is controlled by Lorenz forces, leading to different segregation patterns. The numerical simulations include studies of two distinctive flow regimes in VAR: strong counter-clockwise Lorentz driven flow and weak clockwise buoyancy driven flow. The results demonstrate possible influence of process instabilities and the electrode composition on the flow regime and thus macrosegregation. The practice of multiple VAR melts is also simulated, showing the effects of each step on the final solute distribution. Experimental validation of the models and other current projects on remelting processes will also be discussed.

Biography

Dr. Matthew Krane is an Associate Professor of Materials Engineering at Purdue University and a member of the Purdue Center for Metal Casting Research. His research is on design, development, and modeling of materials processes, particularly the solidification of metal alloys. He holds a Ph.D. (1996) from Purdue University in Mechanical Engineering, with a concentration on heat transfer and fluid flow in materials processing. His M.S. (1989) is from the University of Pennsylvania and his B.S. (1986) from Cornell University, both in mechanical engineering. In addition to consulting with the metals processing industry, he also worked for three years (1988-1991) on thermal packaging and manufacturing issues for Digital Equipment Corporation in Andover, Massachusetts. In 2006, he was a Visiting Research Fellow working in the Interdisciplinary Research Centre at the University of Birmingham (UK) and was granted a courtesy appointment in Purdue’s School of Mechanical Engineering in 2008. Serving on several technical committees in the ASME and TMS, including holding the chair of the TMS Process Modeling and Control (2001-2003) and Solidification (2009-2011) Committees, he has organized or co-organized several symposia in his areas of research, including the Tenth International Conference on Modeling of Casting, Welding and Advanced Solidification Processes (MCWASP X) in 2003 and the Liquid Metal Processing and Casting Conference (LMPC) in Nancy, France in 2011. He is on the international technical committees for the MCWASP and the LMPC conference series. Professor Krane’s teaching experience includes heat transfer, fluid mechanics, engineering design, materials processing, numerical modeling, and ethics in engineering practice.

Best Paper Award

View the paper on SpringerLink

The paper “The microwave processing of electric arc furnace dust” by Xiang Sun, Jiann-Yang Hwang and Xiaodi Huang is among one of the 2011 TMS-EPD Technology Best Paper Award selections. JOM JOURNAL OF THE MINERALS, METALS AND MATERIALS SOCIETY , Volume 60, Number 10, 35-39, DOI: 10.1007/s11837-008-0132-x

Sun, Hwang, and Huang are recipients of the 2011 EXTRACTION & PROCESSING DIVISION TECHNOLOGY AWARD. This award recognizes a paper or series of closely related papers with at least one common author which represents a notable contribution to the advancement of the technology of extraction and processing metallurgy with emphasis on nonferrous metals.