News Article | March 2, 2017
While his childhood friends built things, Erik was always more intrigued by how and why things break. Prof. Dr. Erik Bitzek has consistently followed this passion for materials, their structures, and their breaking points. This Ludwigsburg Native never minded if his observations were drawn from stones in his mineral collection, his favorite chocolate, or steel. After studying physics in Stuttgart, Bitzek started his doctorate at the Max Planck Institute for Metals Research (now MPI for Intelligent Systems), turning this vocation into a profession. Now he has received a coveted ERC consolidator scholarship worth two million euros from the European Research Council (ERC) -- to explore even more intensively why things break apart. With his latest research project 'microKIc -- Microscopic origins of fracture toughness' at the Friedrich-Alexander University Erlangen-Nuremberg (FAU), Bitzek aims to describe the interactions between cracks and material defects, and investigate the factors influencing breakage and destruction. "We do not know enough about the breaking processes in metals, in intermetallic compounds, or in semiconductors, to make theoretical predictions about the breaking strength of these materials," explains Bitzek. However, it is so important to understand these processes precisely - it is a matter of life and death! For example -- in the construction and transport business, for the construction of components and machines, or the design of reactor pressure vessels -- resistance to the spread of cracks is an essential property of the materials used, such as steel. How do fracture processes - which start on the smallest atomic scale long before we can see a crack with the eye - depend on microstructure, temperature or loading rate? These are questions the FAU scientist will investigate during his project. Starting from simulations with several millions of atoms, he will develop micromechanical models for breaking strength and compare these with fracture tests carried out directly in the scanning electron microscope. When materials are subjected to a load, cracks are the usual consequence. These do not spread two-dimensionally but always three-dimensionally. Therefore, investigating the early stages of crack formation in 3-D models, and with different simulation methods for the individual length scales, promises particularly realistic results. They are intended to give researchers a comprehensive understanding of the microscopic processes at the tip of the breaking ridge. This helps materials scientists to then develop novel, fail-safe materials and further improve the design guidelines for safety-relevant structures and components. The fact that Erik Bitzek is doing outstanding work in this field of research is easy to underline by glancing at his previous career. Before taking up a professorship for materials science (simulation and material properties) at the Chair of Materials Science (General Material Properties) in Erlangen, he was contributing substantially to the establishment of the new Institute for Reliability Components and systems at the Karlsruhe University of Technology (Karlsruhe Institute of Technology (KIT)). After completing his doctorate in mechanical engineering at the KIT, he researched at the Paul Scherrer Institute in Switzerland, at the Ohio State University in Columbus, Ohio, and at the University of Pennsylvania in Philadelphia, Pennsylvania. Bitzek has been a board member of the research training group "GRK1896 - in situ microscopy with electrons, x-rays and raster probes" and he has been responsible for the Elite Master's Program 'Advanced Materials and Processes' (MAP) since 2013. In addition, he was awarded the EAM Starting Grant in 2013 by the FAU's Cluster of Excellence 'Engineering of Advanced Materials' (EAM) in order to launch individual projects and improve his chances for the acquisition of funding within the national and international framework - an investment that has now paid off. One thing, of course, is diminishing with his increasing success: similarities between comic fan Erik Bitzek and his favorite cartoon character, Gaston Lagaffe. Unlike the quirky anti-heroine of André Franquin's pen, chaos and destruction are now found mainly in Bitzek's computer and not in his immediate environment. "But I still find it fascinating when something breaks down in real life," laughs Bitzek.
Dasgupta R.,Advanced Materials and Processes
Tribology International | Year: 2010
One of the advantages reported in Al-base alloy particulate composites is its improved sliding wear properties over its base alloy by several investigators. Much of the improvement depends on the experimental conditions, alloy composition as on the particulate size, shape and distribution in the matrix. The present paper will make an attempt to assess the improvement in sliding wear properties attained in a few Aluminium base alloys with different size, quantity and distribution of SiC-particulates and bring out the efficacy of making composites if any in the different alloy systems over other methods of property improvement like homogenisation, secondary processing, etc. In some cases remarkable improvements have been achieved, such as the composites have sustained much harsher conditions whereas the base alloy has seized at much milder conditions; whereas in other alloy systems the improvement is only comparable to that obtained by secondary processing. Properties attained on homogenisation, extrusion and making composites would be compared with the base alloys. In this paper an attempt will be made to draw a line as to the conditions under which composites can been used to make engineering products where improved sliding wear resistance is demanded and where more prevalent methods like ageing could serve the purpose. © 2009 Elsevier Ltd. All rights reserved.
Maheshwari A.K.,Advanced Materials and Processes
Computational Materials Science | Year: 2013
In this study, a new phenomenological material flow model is established and validated to describe the dynamic deformation behavior of Al-2024 alloy with respect to the wide range of strain rate, strain, and temperature. When compared to the JC Model and Modified JC Model, it is found to give a more accurate and precise estimate of the experimental output. The main advantageous feature of the proposed model over many other models is that it requires the experimental data results of compression test only and at the same time it retraces the experimental outcome with higher efficiency. © 2012 Elsevier B.V. All rights reserved.
Prasad B.K.,Advanced Materials and Processes
Tribology International | Year: 2011
This investigation pertains to the influence of some test parameters like applied load, sliding speed and test environment on the sliding wear behaviour of a grey cast iron. Properties studied were wear rate, frictional heating and friction coefficient in dry and oil lubricated conditions. The wear response of the samples has been discussed in terms of specific characteristics like load bearing, lubricating and cracking tendency of different microconstituents of the cast iron. Examination of wear surfaces, subsurface regions and debris particles has also been carried out to understand the operating wear mechanisms and further substantiate the observed response of the samples. © 2011 Elsevier Ltd. All rights reserved.
Hirsch A.,Advanced Materials and Processes |
Englert J.M.,Advanced Materials and Processes |
Hauke F.,Advanced Materials and Processes
Accounts of Chemical Research | Year: 2013
The fullerenes, carbon nanotubes, and graphene have enriched the family of carbon allotropes over the last few decades. Synthetic carbon allotropes (SCAs) have attracted chemists, physicists, and materials scientists because of the sheer multitude of their aesthetically pleasing structures and, more so, because of their outstanding and often unprecedented properties. They consist of fully conjugated p-electron systems and are considered topologically confined objects in zero, one, or two dimensions.Among the SCAs, graphene shows the greatest potential for high-performance applications, in the field of nanoelectronics, for example. However, significant fundamental research is still required to develop graphene chemistry. Chemical functionalization of graphene will increase its dispersibility in solvents, improve its processing into new materials, and facilitate the combination of graphene's unprecedented properties with those of other compound classes.On the basis of our experience with fullerenes and carbon nanotubes, we have described a series of covalent and noncovalent approaches to generate graphene derivatives. Using water-soluble perylene surfactants, we could efficiently exfoliate graphite in water and prepare substantial amounts of single-layer-graphene (SLG) and few-layer-graphene (FLG). At the same time, this approach leads to noncovalent graphene derivatives because it establishes efficient π-π-stacking interactions between graphene and the aromatic perylene chromophors supported by hydrophobic interactions.To gain efficient access to covalently functionalized graphene we employed graphite intercalation compounds (GICs), where positively charged metal cations are located between the negatively charged graphene sheets. The balanced combination of intercalation combined with repulsion driven by Coulombic interactions facilitated efficient exfoliation and wet chemical functionalization of the electronically activated graphene sheets via trapping with reactive electrophilic addends. For example, the treatment of reduced graphite with aryl diazonium salts with the elimination of N2 led to the formation of arylated graphene. We obtained alkylated graphene via related trapping reactions with alkyl iodides.These new developments have opened the door for combining the unprecedented properties of graphene with those of other compound classes. We expect that further studies of the principles of graphene reactivity, improved characterization methods, and better synthetic control over graphene derivatives will lead to a whole series of new materials with highly specific functionalities and enormous potential for attractive applications. © 2012 American Chemical Society.
Saridakis E.,Advanced Materials and Processes |
Chayen N.E.,Imperial College London
Trends in Biotechnology | Year: 2013
Molecularly imprinted polymers (MIPs) are 'smart materials' polymerised in the presence of a template molecule, of which they retain a chemical 'memory'. When the template molecule is extracted from the polymer, it leaves behind cavities that are complementary to it, thus making the material capable of rebinding that molecule with high affinity and selectivity. Such materials, imprinted both with small molecule and with protein templates, have been used in chromatographic, chemical, and biological sensing applications. Here, we review a variety of uses for MIPs, focusing on their recently discovered role as nucleation inducing substances for protein crystals. This discovery makes them useful tailor-made 'nucleants' to be used both for optimisation of protein crystal growth and for discovering new crystallization conditions. © 2013 Elsevier Ltd.
Eigler S.,Advanced Materials and Processes
Chemical Communications | Year: 2015
Graphite sulphate is used as a precursor to graphene for the first time. The positively charged graphene layers react with water to yield a processable graphene derivative. The unprecedented low density of defects is determined to be 0.06% on average and may open the way for electronic applications. This journal is © The Royal Society of Chemistry 2015.
Agency: National Science Foundation | Branch: | Program: STTR | Phase: Phase II | Award Amount: 461.79K | Year: 2009
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This Small Business Technology Transfer Phase II project will change the paradigm that two-phase chemical reactions must use mechanical mixing to be commercially effective. The innovative Fiber Reactor (TM) offers two orders of magnitude change in efficiency for chemical and biochemical manufacturing. This project will focus on biodiesel transesterification reactions. Biodiesel plants convert fats/oils to biodiesel with multiple reactor stages and centrifuge stages. Complexity is due to poor mass transfer, poor reaction conversion, and poor phase separations due to by-product soap. Improving mass transfer and eliminating soap dispersions will reduce the cost of manufacturing biodiesel. In Phase I experiments, the Fiber Reactor was 3-100 times faster than commercial biodiesel processes with superior conversion. Advanced Materials and Processes has found an unconventional way to improve mass transfer and simultaneously solve phase separation problems in biodiesel processes. Use of a Fiber Reactor will reduce complexity, size, capital, energy consumption, and water pollution by dramatically improving mass transfer and eliminating dispersions. Phase I proved feasibility of energy savings and process intensification in biodiesel manufacturing. Phase II will use Phase I models and CHEMCAD models to design and operate a pilot reactor using the high throughput continuous static Fiber Reactor and wash processes. Biodiesel capacity could increase 10 times by 2015 and improve U.S. energy security. Two hurdles remain - produce the triglyceride needed and match petroleum economics. A new industry and networks are being developed to supply enough algae oil. Fiber Reactors will reduce capital and operating cost for producing biodiesel by 50% and use low cost crude oils/fats. Phase I developed basic transesterification chemistry for Fiber Reactors. Phase II will develop chemistry/engineering data for scale up. Fiber technology will apply to pharmaceutical and specialty chemical manufacturing with similar benefits. This project will integrate research and education by training students in organic chemistry, fibers, materials, processes, pilot operations, fractionation, analysis, organic synthesis, and quality control. Students use wet chemistry, GPC, HPLC and LC/MS for identification/quantification of raw materials and reaction products. Texas State University graduated 46 chemistry/biochemistry majors in 2008. Enrollment in 2009 included 329 chemistry/biochemistry majors. The 37 graduate students were 35% minority and 48% women. IEIS has provided research assistantships/employment to over 100 students of whom 62% were women or minorities. This project will have a positive impact on the research capabilities of academic departments and IEIS; and help women and minorities to improve their training in industrial chemistry.
Agency: Department of Defense | Branch: Army | Program: STTR | Phase: Phase II | Award Amount: 749.62K | Year: 2010
The purpose of this STTR Phase II project is to continue research and development on novel fire resistant thermal barrier coatings (TBC) with low temperature flexibility. Polyurethane coatings are the most important segment of aircraft coatings. Excellent
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 100.00K | Year: 2010
The objective of this SBIR Phase I project is to produce a tough protective nanocomposite ceramic lining for machine gun barrels to reduce weapon system acquisition costs through service life extension, reduction in parts consumption & failure rates, reduction in weapon weight, reduced corrosion, and reduction in barrel heat load. We postulates that incorporation of a ceramic radiant barrier lining will send more heat out the nozzle with numerous benefits. Advanced Materials and Processes has identified candidate materials and processing techniques that will produce integral tough nanocomposite ceramic linings for outstanding barrel life. The process is applicable to machine gun barrels of any size. AMP will prepare two prototype ceramic gun barrel coatings and test for hardness, crack resistance, adhesion, thermal conductivity, and live firing. FN Manufacturing (FNMI) is collaborating on this project. FNMI will provide barrel tubes and technical support in Phase I. They will also provide 2000 round live fire testing/evaluation of two prototype coated gun barrels in Phase I and 10000 round live fire testing/evaluation of one prototype in Phase I Option. FNMI believes that the proposed ceramic liners are worth investigating because if successful they will enable a quick implementation and practical way to production.