Virtual Seminar Series | Thermomechanical processing for metal manufacturability and performance
All dates for this event occur in the past.
Seminar by Kester Clarke
Assistant Professor
Forging Industry Educational and Research Foundation Professor
Colorado School of Mines Dept. of Metallurgical and Materials Engineering
Metallic alloy processing and service conditions have significant effects on our ability to manufacture metals with desired microstructures and implement those metals in performance critical applications. Accumulative roll bonding (ARB) affords the ability to create fine-grained microstructures with otherwise unobtainable properties, but bulk manufacturability is limited by severe edge cracking that occurs due to the necessary large, single-pass rolling reductions. Here we show that lateral constraint can significantly reduce or eliminate edge cracking and maintains improved thickness homogeneity during ARB of aluminum alloys. This methodology greatly improves sample quality and yield when applied to multiple ARB cycles and is scalable to bulk manufacturing processes. Similarly, quenching and partitioning (Q&P) processing of third-generation advanced high strength steels generates multiphase microstructures containing metastable retained austenite and has produced cost-efficient structural steels with unprecedented performance for automotive structural applications. That performance is most commonly quantified in the laboratory by tensile testing at quasi-static strain rates. Both manufacturing processes such as stamping and in-service deformation due to crash events deviate significantly from the strain state, path, rate, and temperature conditions commonly tested. Thus, tailoring austenite stability is critical for optimizing the forming response and crash performance of quenched and partitioned grades.
Dr. Kester Clarke is an assistant professor in the Metallurgical and Materials Engineering Department at Colorado School of Mines and serves as the Forging Industry Education and Research Foundation (FIERF) Professor and holds a joint appointment as a scientist at Pacific Northwest National Laboratory (PNNL). He engages in research on deformation processes in metal alloys with the Center for Advanced Non-Ferrous Structural Alloys and the Advanced Steel Processing and Products Research Center. His research interests include alloy development, material deformation and fabrication processes, and the use of experimental and modeling methods to examine the effect of material processing history and microstructure on mechanical properties and performance. Dr. Clarke holds a B.A. in Psychology from Indiana University, a B.S. in Materials Science and Engineering from Wayne State University, and M.S. and Ph.D. degrees in Metallurgical and Materials Engineering from the Colorado School of Mines. He has worked as a consulting Metallurgical Engineer for Engel Metallurgical and as a Senior Engineer/Research and Development for Caterpillar. He conducted postdoctoral research at Los Alamos National Laboratory, was an R&D scientist/engineer in the Materials Science & Technology: Metallurgy group serving as the technical lead for thermal-mechanical processing of metals and metal component fabrication and is currently a Visiting Scientist at LANL.
Kester D. Clarke
(he, him, his)
Forging Industry Educational and Research Foundation (FIERF) Professor
Assistant Professor | George S. Ansell Department of Metallurgical and Materials Engineering
Colorado School of Mines | 1500 Illinois St., Golden, CO 80401
Office: Nathaniel P. Hill Hall, 920 15th St., Room 374
303-384-2301 | kclarke@mines.edu