The Krause Group explores microstructure evolution, grain boundary structure-property relationships, and crystal nucleation and growth in ceramics. Our goal is to tune material properties with microstructural design via powder processing. To accomplish this goal, we specialize in microstructural characterization with electron and x-ray microscopy techniques. Learn more about who we are and our research projects.
Congratulations to Dr. Bryan Conry for successfully defending his thesis in July! He is moving on to a position at Oak Ridge National Laboratory.
Congratulations to Vivek Muralikrishnan and Daniel DeLellis for passing their overviews this August.
Dr. Bryan Conry, Daniel, DeLellis, Vivekanand Muralikrishnan, and Dr. Krause gave talks the Rex&GG conference in Copenhagen Denmark. Dr. Krause also presented at the workshop on "Intersection of Materials Science and Machine Learning" hosted by the Air Force Research Lab.
Dr. Bryan Conry published his third first-author paper. This paper includes co-authors Molly Kole and W. Ryan Burnett, who worked on this project as undergraduates at University of Florida.
Dr. Krause taught 14 5th-8th graders at the Gelfand Center's GO Summer Class on "Engineering Unbreakable Ceramics." These students got to learn about the properties and uses for ceramics in their life. They also got to make and break(!) their own composites to learn strategies used to improve the toughness of ceramics.
Krause group was well represented at the American Ceramic Society conferences in January. Bryan Conry gave an invited talk at the International Conference and Exposition on Advanced Ceramics and Composites (ICACC). Daniel DeLellis presented his first poster at a professional conference at ICACC and was a co-author on another abstract. Dr. Krause chaired the Electronic Materials and Applications (EMA) Conference, where Vivek Muralikrishnan presented his poster.
National Lab Trips
The group collected a lot of data this semester, requiring two trips to national labs. Vivek Muralikrishnan, Yi Wang, Hao Zhu and Dr. Krause (accompanied by Dr. Bob Suter and Zipeng Xu) traveled to APS (Advanced Photon Source) at Argonne National Lab to complete grain growth studies using high energy x-ray diffraction microscopy in March. Bryan Conry, Daniel DeLellis, and Dr. Krause conducted slip casting and grain growth experiments with collaborator Dr. Mike Kesler at Oak Ridge National Laboratory (ORNL) in April.
Dr. Krause participated in the Society of Women Engineer's Middle School Day. She introduced materials science to middle school girls, who got to make their own slime!
Dr. Krause gave a seminar on how to write strong scientific hypotheses to graduate students in MSE at the CMU professional development series.
Awards and Recognitions
Dr. Krause was awarded the Wimmer Faculty Fellowship to introduce creativity into Microstructure & Properties I for juniors in MSE.
She was also recognized by the American Ceramic Society Bulletin for the Volunteer Spotlight.
X-ray Xradia Context with LabDCT installed
The new X-ray Xradia Context with LabDCT was installed in the Materials Characterization Facility (MCF) in January. The Krause Group is looking forward to using this tool for its current projects.
Krause Lab Moves to CMU
In August 2022, the Krause lab moved from Gainesville, FL to Carnegie Mellon University. We are enjoying exploring Pittsburgh.
New Group Members
Welcome to Yi Wang and Hao Zhu!
We had a productive publication list this fall. Congratulations to Amanda Velázquez Plaza and Vivek Muralikrishnan, who each published their first first-author papers in the group, as well as Bryan Conry for his second first-author paper. Dr. Krause also published with her new CMU colleagues in the invited Annual Review.
American Ceramic Society Awards
Congratulations to Bryan Conry and Vivek Muralikrishnan for winning the GEMS Sapphire Awards at this year’s Materials Science & Technology Conference.
Dr. Krause gave invited talks at Materials Science & Technology Conference (MS&T) and Materials Research Society (MRS) Fall Meeting. She also gave a seminar at University of Pennsylvania.
Before joining the Materials Science and Engineering Department at Carnegie Mellon University in 2022, she was an assistant professor of MSE at the University of Florida (2019-2022). She received her B.S. and M.S. in Materials Science and Engineering from Virginia Tech, and her Ph.D. in Materials Science from Brown University. From 2016-2018, she was a lecturer and post-doctoral research associate at Lehigh University. Her research focus is engineering grain boundaries and interfaces for improving the mechanical performance, degradation response, and thermal properties of ceramics used in extreme environments. She is a recipient of the NSF CAREER award (2022).
Mehmet Can Dursun
Dr. Bryan Conry, PhD (2023). Dissertation: "Anisotropic Grain Boundary Networks and Their Role in Abnormal Grain Growth"
Capturing Microstructure Evolution with 4D X-ray Diffraction Microscopy
Grain growth is a fundamental material mechanism which governs how the majorities of materials will behave in operation. The model for grain growth can typically predict the average behavior but struggles with outliers, which play an outsized role in material properties. Experimental limitations have restricted testing the model for grain growth to only ideal cases. However, recent advances in 3D x-ray diffraction microscopy have made it possible to observe grain growth in real polycrystalline materials and track the same grain boundaries with time. In our study of strontium titanate (SrTiO3, a dielectric material), we observe that grain boundaries do not move in the direction of curvature, suggesting that the grain growth model used is not applicable to real polycrystals. We are investigating other potential local driving forces to explain grain boundary motion.
Paper: Muralikrishnan et al. Scripta Mater. 222:115055 (2023). https://doi.org/10.1016/j.scriptamat.2022.115055
Predicting Abnormal Grain Growth by Machine Learning
Ceramics with impurities have a propensity to undergo abnormal grain growth, where a small fraction of grains grow much faster than the majority of grains. Such growth can be undesirable because the properties are hard to predict of a material with a heterogeneous microstructure. However, no simulations have been able to predict such type of growth from the current understanding of grain growth. In a collaboration with University of Florida and Oak Ridge National Lab, we use machine learning to capture the unique grain growth behavior.
Paper: Yan et al. Mater. & Design 222:111032(2022).
Impervious Environmental Barrier Coatings: Controlling Crystal Nucleation and Growth
Environmental barrier coatings are used to protect ceramic-matrix-composites (CMCs) for use in gas-turbine engines (aerospace or power generation engines). These ceramic coatings must be dense to prevent CMCs from high-temperature reactions with steam that cause part failure. A large challenge is that environmental barrier coatings must also be impervious to molten silicates (dirt, sand, ash, etc) that get pulled into the engine during operation. The coatings' composition must be chosen carefully to create a desirable reaction with the silicates that prevent further attack. Current approaches have focused on thermodynamics of the reaction with little attention to how the kinetics influence the growth behavior. We explore how the kinetics of the reaction can be altered to improve protection from silicate attack.
Paper: Velázquez Plaza and Krause, Coatings 12:1604 (2022). https://doi.org/10.3390/coatings12101604
How to resist crack growth: Laser shock peening of ceramics
Ceramics are brittle and prone to drastic failure, preventing their implementation in many high temperature applications. A common way to improve the crack resistance of a material is to impose a residual compressive stress (cracks propagate in tension). In metals, this can be done with post-processing steps such as shot peening or laser shock peening, where the surface of the material is bombarded with shot beads or a wave, respectively. The metal is plastically deformed and develops a residual compressive stress. It has been demonstrated that ceramics can also be laser shock peened with similar increases in compressive residual stress. However, it is not clear by which mechanism the ceramics can build residual stresses. Furthermore, it is unclear how impurities at the grain boundaries interact with the incoming wave. In a collaboration with University of Nebraska-Lincoln, we explore these mechanisms in alumina, silicon carbide, and silicon nitride.
Paper: Wang et al. J. Amer. Ceram. Soc. 105:2411 (2022).
Krause and Abbott receive NSF CAREER Awards
CMU College of Engineering’s Krause and Abbott receive NSF CAREER Awards for their research in materials science and biomedical engineering.
Krause and Wang named Wimmer Faculty Fellows
CEE’s Jerry Wang and MSE’s Mandie Krause have been named Wimmer Faculty Fellows at the Eberly Center for Teaching Excellence and Educational Innovation.
Materials Science and Engineering
Krause leans into creativity with ceramics
Assistant Professor Mandie Krause is a ceramicist passionate about merging engineering and art. She joined CMU this fall.