In the general frame of energy saving, environment protection and the concept of circular economy, the fundamental research on the sintering technology with super deep bed, achieving energy saving and emission reduction, was carried out. At first, the characteristics of the process and exhaust emission in the sintering with super deep bed was mastered through the study of the influence of different bed depths on the sintering process. Then, considering the bed permeability and the fuel combustion, their influence on the sinter yield and quality, their potential for energy saving and emission reduction was studied. The results show that the improvement of the bed permeability and of the fuel combustibility respectively and simultaneously, leads to an improvement of the sintering technical indices, to energy saving and emission reduction in the condition of super deep bed. At 1000 mm bed depth, and taking the appropriate countermeasure, it is possible to decrease the solid fuel consumption and the emission of CO2, SO2, NOx by 10.08%, 11.20%, 22.62% and 25.86% respectively; and at 700 mm bed depth, it is possible to reduce the solid fuel consumption and the emission of CO2, SO2, NOx by 20.71%, 22.01%, 58.86% and 13.13% respectively. This research provides the theoretical and technical basis for the new technology of sintering with super deep bed, achieving energy saving and reduction of emission.

En déformant in situ dans un microscope électronique en transmission des micro éprouvettes de l’alliage d’aluminium 6056 T6, les micromécanismes responsables de sa résistance mécanique ont été identifiés. Il a été montré que les dislocations s’ancrent sur des lignes nommées lignes d’ancrage et qu’elles se propagent par bonds entre ces lignes. Les grandeurs physiques qui décrivent ces lignes ont pu être mesurées. Il apparaît que le glissement dévié des dislocations est très actif dès la température ambiante. Ce glissement dévié se produit souvent entre plans octaédriques mais aussi entre plans octaédriques et plans cubiques. L’incidence de ce mécanisme sur les propriétés mécaniques a été analysée.

Bulk metallic glasses foams are under consideration as highly functional material, such as energy absorbers or ultra-lightweight parts, due to their porous structure combined with desirable strengths at relatively low densities. Also, the characteristics of high surface area of foams synthesized from metallic glasses make them viable candidates as emerging materials such as high-sensitivity sensors, catalysts or hydrogen storage media. In current study, bulk metallic glass foams were fabricated by extruding powder mixtures comprised of metallic glasses blended with various kinds of fugitive phases followed by dissolution of the fugitive phases in an aqueous chemical solution, for example HNO3, to yield the final porous structure. As a result of dissolution process, porous metallic glass having uniformly distributed micro-scale porosity was fabricated using a sequential synthesis technique beginning with composite particles comprised of composites of MG and a fugitive phase followed by consolidation of the composite powders via warm extrusion.

Segregation is an important phenomenon which heavily affects the final mechanical properties of steel products. The presence of several complex physical phenomena resulting in final segregation pattern in as-cast products makes the quantitative prediction of macro-segregation for industrially relevant casting processes extremely difficult. In the present work, a reliable prediction of important rolled product quality (in terms of mechanical and Charpy impact properties) which are linked to segregation is achieved for plate rolled pipeline steels by exploiting data related to the as-cast structure and caster operational data (including casting machine condition) through the application of neural networks. In particular, a hierarchical approach is proposed for the prediction of the Charpy Impact Value, in order to reflect the physical link between this quantity and the Ultimate Tensile Strength. The neural predictor has been developed by exploiting real industrial data and its performance can improve through time by enlarging the database that is used for its training.

An impressive number of papers are published each year that report on continuously-cast steel quality issues and new machine equipment; few of them (if any) discuss productivity and cost issues as they should be addressed by plant management, caster operators, and scientists. At Management & Quality Control meetings in steel plants, much time is spent discussing tenth of percent rejections at the end of the processing line. But, little time is devoted to discuss slab direct-application ratios where rejections are several percents and penalty on the overall scheduling and organization of the steel production line very serious. At IPC & SOP review meetings (Integrated Process Control & Standard Operating Practices review meetings), much time is spent discussing upper and lower statistical (6-sigma) control-limit diagrams. However, no mention is made that such diagrams only prove process capability (process repeatability and reproducibility) and not product quality. There should be no comfort if center line is at 10% slab abnormality code month after month! It is the goal of the author to draw from an approach that combines 30+ years of research and plant experience. The result is the opportunity to “connect the dots” and a wide breadth of in-situ process understanding. The paper looks at continuous casting machines as tools for maximizing corporate earnings. It is about making good steel on the first attempt. Very systematically and practically, the paper discusses disturbing steelmaking defects, their causes, and how Electro-Magnetic Stirring technology can be used to eliminate them. It draws the attention to academics looking to validate or invalidate what they know or don’t know, and provides in-depth, concise, practical explanations and guidelines to plant operators who are less interested or do not have the time to assimilate highly-technical presentations and publications.

Le but de l’étude est de caractériser et de modéliser le comportement mécanique cyclique à l’ambiante du magnésium pur extrudé, en particulier sous chargement cyclique. Des essais de traction, compression et des essais cycliques, ont été réalisés (avec de petites déformations, respectivement Δεp/2 = 0,1 % et 0,4 % dans les essais cycliques). Les modes de déformation (glissement, maclage) ont été observés par Microscopie Electronique à Transmission, ce qui a permis de déterminer les cissions résolues critiques. Un modèle de plasticité cristalline s’appuyant sur ces observations a été développé. L’asymétrie de comportement entre traction et compression provient de l’activation de systèmes de glissement (pyramidal et prismatique  ⟨a⟩  et pyramidal  ⟨c + a⟩) en traction, et de l’activation du maclage en compression. Dans tous les cas, le glissement basal est très facile à activer, même pour de faibles facteurs de Schmid. La simulation numérique montre qu’il faut prendre en compte le démaclage lorsqu’une traction suit un passage en compression afin de modéliser la forme en S des courbes d’hystérésis. Les observations au MET montrent également d’intenses glissements secondaires dans les zones maclées sous chargement cyclique, si bien que tant le maclage en compression que le glissement des dislocations en traction sont impactés par le maclage. Les simulations numériques sont en très bon accord avec l’expérience, pour ce qui concerne les réponses macroscopiques contrainte-déformation, mais également pour la fraction maclée.

New glassy, crystalline and glass-crystalline materials from the GeSe2-Sb2Te3-CdTe system are synthesized by melt quenching technique. Using the results of the performed syntheses, X-ray diffraction analysis and scanning electron microscopy the glass forming region within this system is outlined. It lies partially on the GeSe2-Sb2Te3 and GeSe2-CdTe sides, as glassy samples are obtained up to 32.5 mol % Sb2Te3 and 27 mol % CdTe, respectively. Some assumptions about the structure of the samples are made on the basis of the results from the XRD investigations.

A novel rheo-rolling process for producing A356 alloy sheet was developed. The influence of parameters on the microstructure of A356 alloy sheets was investigated. The eutectic fraction and primary α globule size increase with the increment in the roll speed. The globule size and eutectic fraction of A356 alloy sheet increase with the increment in the casting temperature. The primary α globule size decreases and the solid fraction increases with the increment in vibration frequency from 30 Hz to 80 Hz. With a roll speed of 0.069 m.s-1, a casting temperature of 660 °C, and a vibration frequency of 80 Hz, A356 alloy sheet with a cross-section size of 4 × 160 mm was prepared. The microstructure is mainly composed of fine spherical or rosette α globules, and the average α globule size is 20.5 μm. The ultimate tensile strength of the A356 alloy sheet was 260 MPa, and the elongation to failure was 7.9%, which were 2.5 and 3.7 times greater than those of the as-cast material.

The basic idea of H2-C mixture reduction reflects the advantages of hydrogen for fast reaction and low heat absorption in a smelting reduction reactor where hydrogen is used as the main reducing agent and carbon as the main heat generator on purpose to cut down the total energy consumption and CO2 emission. This work aimed at the experimental investigation of the optimal carbon/hydrogen ratio, a key parameter of iron oxide reduction with mixture reductive agents of carbon and hydrogen. Experiments were carried out using a pure Al2O3 crucible which was placed in a tubular furnace for high temperature. Two investigation methods were adopted: one was injecting an acetylene/hydrogen mixture reducing gas into molten iron oxides, and the other was blowing hydrogen into an iron bath during continuous feeding of fine ore mixing solid carbon. Parameters such as the apparent de-oxidation rate and utilization ratio of reductive agents were calculated from content analysis of the exhaust gas after dust removal and drying. In the experiments the highest total de-oxidation rate and satisfactory apparent utilization ratio of hydrogen were obtained under conditions with temperatures of 1823 K and the carbon/hydrogen ratio in the region of 0.5:1 to 1:1.

The impact of the use of particular materials on the environment and society can be assessed in a number of ways, including through the impact on natural resources, contribution to environmental burden and effects on the quality of human life. In this context, indicators such as embodied energy, exergy, TMR (total material requirement), ecological footprint, social indicators (such as effects on human health) and LCA based on these indicators, are available. We apply the concept of energy networks 1 (quoted in Appendix O), to explore the differences in energy network impact due to processes for the production of various materials, each time with an equivalent end-use in mind. The inventory analysis part of LCA has been carried out on materials, as well as some work on impact assessment (LCIA) for resource use, pollution severity and health impact. The indicators proposed here aid the assessment of the energy system impact, particularly with regards to opportunity costs to society, impact on equity in society and the administrative burden on society due to the current energy networks. The indicators are: embodied energy, the maximum process temperature, the annual use energy, and network reliance. Three case studies are employed to explore the usefulness of the indicators, including a beverage container, a house window frame and a beverage bottle transport crate. These case studies show that for a particular end use, different materials can have wide differences in the proportion of energy sourced from energy networks (a factor of 95 observed in one case). The indicators also offer a quicker indication than life cycle assessment and allow deduction of impacts on a wider social system. The indicators have the potential to change material development and process design trends towards processes which are less burdensome on energy networks.

The vehicle braking system is considered as one of the most fundamental safety-critical systems in modern vehicles as its main purpose is to stop or decelerate the vehicle. The frictional heat generated during braking application can cause numerous negative effects on the brake assembly such as brake fade, premature wear, thermal cracks and disc thickness variation (DTV). In this paper, transient and contact analysis of the brake disc is presented. The analysis was carried out using ANSYS Multiphysics 11.0 based on the thermomechanical coupled case. The temperature distribution obtained by the transient thermal analysis is used in the calculations of the stresses on the disc surface. The results presented are for the temperature during contact, for different values of time, deformations established in the disc, total stress and pressure contact distribution in the pads. The results obtained by the simulation are satisfactory compared with those of the specialized literature.

The carbon footprint is allocated today to CO2 emission sources, and thus to industries with smokestacks, machines with tailpipes or countries burning coal and oil; emission factors are also calculated, i.e. emissions per unit of production, of use, per capita or per unit of GDP. This is, however, not the only way to allocate emissions in a value chain and this could also be done at the source (cradle) of the carbon that will later end up being oxidized. Comparing countries with this new metrics points to fossil fuel producers as the major “cradle producers” of CO2, thus giving a fairly different geopolitical view of the “polluting” world. Beyond issues of responsibilities, related to the polluter pays principle, this new method can help exhibit solutions for mitigating emissions that usually are not imagined or discussed, and examples thereof are given.

The glass-forming ability of chalcogenide glasses from the GeSe2-Sb2Te3-PbSb2Te4 system is investigated at different cooling rates. The samples are synthesized by direct synthesis in evacuated quartz ampoules from the initial compounds and quenched in air, water, water+ice+NaCl and liquid nitrogen with cooling rates of 3, 9, 34 and 400 K/s, respectively. The obtained bulks are characterized by visual and X-ray diffraction analyses. The critical cooling rate for obtaining chalcogenide glasses from the investigated system is 34 K/s. Above this rate the border between the glassy and crystalline phases shows a tendency towards narrowing of the glass-forming region.

Formation of deposits inside the submerged entry nozzles used in continuous casting of especially low-silicon Al-killed mild steels may often cause nozzle clogging and casting disorder. Technological experience has shown that the application of Ca-treatment before casting usually eliminates this phenomenon. In order to understand deposit formation and the way it can be avoided, we have carried out detailed mineralogical analyses of the deposits formed on the inner and outer surfaces of the nozzles by different techniques. Results obtained from deposits formed during the casting of only Al-killed and subsequently Ca-treated steels show that the results obtained from deposits formed during the casting of only Al-killed and subsequently Ca-treated steels show that the alumina inclusions carried to the wall of the nozzle form the matrix of the dangerous deposits. Application of Ca-treatment resulted in mostly liquid aluminates compounds and almost negligible deposit formation. The outer surface of the nozzles however showed similar deposit formation because of possible reoxidation of dissolved aluminium.

Three typical cokes were used for experiments in order to clarify the relationship between coke properties and solution loss behavior and its influence on the post-reaction strength of coke. Isothermal reactions between coke and CO2 at 1050–1300 °C were stopped at a weight loss of 25%. The post-reaction strength of coke was tested by an I-Type tumbler. Coke chemical reactivity and pore structure were tested to analyze the coke properties. The results show that the reaction temperature caused the most serious degradation to three cokes that were different due to their different properties. If two kinds of coke have similar chemical reactivity, the one with the less developed pore structure has a lower temperature, causing the most serious degradation. If two kinds of coke have similar pore structure, the one with the higher chemical reactivity has a lower temperature, causing the most serious degradation. This knowledge contributes to a reference for evaluating the capability of coke strength for resisting solution loss.

The maximum value at equilibrium of the relaxed enthalpy of some glasses is viewed as a linear function of the annealing temperature from the Kauzmann temperature TK up to a vitreous transition temperature T*g which is not time dependent. The frozen enthalpy and entropy at T*g are determined from the specific heat difference between glass and undercooled melt which is constant between TK and T*g. The Gibbs free energy change at T*g is equal to zero. The vitreous transition is a thermodynamic transition without latent heat. A model is used to describe this phenomenon. A volume energy saving εv equivalent to a complementary Laplace pressure has been added to the classical Gibbs free energy change for a crystal formation in a melt. There is a change of the Vogel–Fulcher–Tammann (VFT) temperature at T*g corresponding to a decrease of the free volume disappearance temperature. Scaling laws linking the crystal homogeneous nucleation temperatures to T*g are used to predict the two VFT temperatures, the thermodynamic vitreous transition induced by vitreous (super)-clusters and the frozen enthalpy and entropy at T*g only knowing T*g, the melting temperature Tm and the fusion heat ΔHm of any fragile glass-forming melt.

As the global economy grows and evolves in the 21st century emerging technologies will require mineral commodities on a greater scale and in a larger number of applications than ever before. The explosive growth in the economies of other nations and the concomitant and explosive increase in demand for raw materials are the reasons for potential supply restrictions. The portfolio of minerals and metals needed for manufacturing is dynamic. If the supply of any of the raw materials used in everyday products and in new emerging technologies was curtailed, many high-tech sectors of the European industries could be significantly affected. For example, the so called “tuning metals” or “spice metals”, although used only in small and essentially as “functional alloyings” in conventional metals are indispensable as “power amplifier” of modern materials used in vehicle construction. These materials are in principle recyclable. However, in most cases it is impossible to recycle them because of the minor concentration in application, thus they are being “consumed”. The Faculty of Georesources and Materials Engineering of RWTH Aachen University is initiating thereupon an integrated interdisciplinary research. The three divisions of the faculty, i.e. Raw Materials and Waste Disposal Technology, Metallurgy and Materials Technology as well as Geosciences and Geography, collaborate on the issue of sustaining critical raw materials availability so that the supply of materials needed for futures industries can be guaranteed. Objective of this research cooperation is to develop life-cycle strategies for critical raw materials which are fundamental for emerging technologies. Securing the availability of raw materials may be accomplished by improving the efficiency of the raw materials chain and by enhancing the raw materials base. Increasing also the knowledge base in this field will enable the European society to transfer more resources into economically efficient and technically manageable as well as politically and socially acceptable mineral and metal reserves. Assuring a sustainable availability of critical metals will be of paramount importance for technical innovations. Researchers and scientists from the Faculty of Humanities at RWTH Aachen University are also involved to study the relation between raw materials supply and economic as well as social matters. Mapping out sustainable strategies for securing the supply of raw materials in the long run requires the competence and input of scientists in fields of natural, engineering, political, economical, and social sciences. Demand and supply of raw materials are affected by the economy, whereas global political and social issues have impact on the same economy.

In recent years, lithium received increasing attention as lithium-ion rechargeable batteries appear to be the most promising candidates for future electric vehicles. Several studies forecast a strong increase in demand most likely brought about with the implementation of lithium-ion batteries in the automotive sector. Thus, the availability of lithium could be an important constraint for this emerging technology. Concerning lithium availability the future developments of supply and demand as well as the recycling potential play major roles. In respect of recycling it has to be distinguished in general between dissipative and non-dissipative applications. As several studies (e.g. 1 G. Angerer, F. Marscheider-Weidemann, M. Wendl, M. Wietschel, Raw materials for emerging technologies: the case of lithium, Karlsuhe 2009) predict lithium recycling to play an important role for future lithium availability the recyclability of lithium in different applications has to be analysed for estimating the contribution of lithium recycling to future supply.

X-ray absorption spectroscopy has been applied to probe the local structure of FeSc nanostructured amorphous solids around Sc atoms. At the Sc K-edge, the Fe90Sc10 nanoglass is characterized by a very short range order (EXAFS oscillations are only present up to k = 8 Å-1). A drastic difference in the phase and the amplitude of the nanoglass EXAFS signal compared to the amorphous ribbon indicating a different local structure around Sc atoms in both structures is observed. In addition, the changes in the local structure around Sc atoms are more significant than around Fe atoms.