Static immersion experiments were conducted to assess the reactivity of austeniticstainless steel grade 316L in contact with molten 55%Al-Zn alloys. The static immersiontests were carried out at bath temperatures of 600 to 650 °C and continuous immersiontimes of 24 to 645 h. The level of reactivity was assessed by measuring the alloy layerthickness that formed on the test coupons after the immersion experiments. The reaction of316L in contact with molten 55%Al-Zn bath results in the formation of two distinct alloylayers on the surface of the steel: one alloy layer forms adjacent to the steel surface(designated “alloy layer 1”) and the other formed between alloy layer 1 and the bath(designated “alloy layer 2”). Characterization of the nature of the alloy layers wascarried out by optical and scanning electron microscopy. Analyses of the chemicalcomposition of alloy layer 1 by SEM/EDS (and taking into account the Al/(Fe + Cr + Ni)ratio) suggest that the alloy layer is most likely based on FeAl2 intermetallicphase. Alloy layer 2, on the other hand, consists of modified ø5c (the normaldross intermetallic phase modified by the substitution of Fe by Cr). After 27 days ofcontinuous immersion at 600 °C, the 316L sample immersed in 55%Al-Zn bath had a totalalloy layer thickness of 423 ¯m. The alloy layer growth is diffusion controlled andfollows a parabolic rate law: at bath temperatures of 600 to 650 °C and continuousimmersion times of up to 27 days, the alloy layer thickness increases approximately withthe square root of immersion time. The parabolic rate constants for the total alloy layerthickness growth were: 2.84 × 10-7 m.s−1/2 at 600 °C,3.34 × 10-7 m.s−1/2 at 615 °C and 6.76 × 10-7m.s−1/2 at 650 °C. Growth of the alloy layers takes place predominantly atthe interface between alloy layer 1 and alloy layer 2, and in part at the substrate/alloylayer 1 interface. The growth of alloy layer 2 is dominated by the inward diffusion ofaluminium, while both inward diffusion of aluminium and outward diffusion of iron arebelieved to play a role in the formation of alloy layer 1.

There is an increasing need for expanding the scope of traditional life cycle studies toanswer system-wide sustainability questions. This has resulted in a framework for lifecycle sustainability analysis (LCSA). Since the framework was first published in 2009, asone of the outcomes of the CALCAS project, several views and considerations concerning themethodological approach have been published. However, until now practical experience withLCSA is very limited. This paper reports first efforts and experiences in bringing theLCSA framework into practice by assessing the sustainability of solar fuels. Startingpoint of the project is the hypotheses that new technologies can only be practicallyimplemented if they fit into a socially, economically and ecologically sustainablecontext. The analysis therefore aims at identifying performance criteria which a newtechnology needs to fulfil in order to compete in the existing market. It is argued that aLCSA study should be initiated with a broad but relevant system description as the firstof in total five steps Of this five step approach, the first – system description – isdiscussed here. The system description identifies and describes the technologicaldescription, the intended application of a technology, which share of specific demand forservice will be met, which other technologies contribute in meeting this demand, the(relevant indicators for addressing )sustainable impacts of meeting the demand anddevelopments over time. By doing so it provides a solid basis for further steps in theLCSA study.

For a better understanding of the physical phenomena associated with the appearance of defects in laser welding, a heat and fluid flow model is developed using Comsol Multiphysics®. This first step of the project is focused on the modeling of a static laser shot on a sample of steel. This 2D axially-symmetric configuration is used to study the main physical phenomena related to the creation of the keyhole. This model takes into account the three phases of the matter: the vaporized metal, the liquid phase and the solid base. To track the evolution of these three phases, coupled equations of energy and momentum are solved. The liquid/vapor interface is tracked using the Level-Set method. The calculated velocity and free surface deformation are analyzed. Melt pool shapes are compared with experimental macrographs and the influence of some parameters such as laser power is discussed.

Equal channel angular pressing is both a novel and an industrialized process among severeplastic deformation methods to fabricate ultra-fine-grained metals and alloys.Verification of a three-dimensional finite element model which compares various strengthcoefficients and strain-hardening exponents (virtual materials) defined for the plasticdeformation behavior of materials was performed with experimental tests. The virtualprocess numerically analyzed the effects of the strain behavior and pressing force. Theresults show that strength coefficient enhancement leads to decreased effective strainvalue, heterogeneous strain distribution and higher pressing force, and an increment inthe strain-hardening exponent results in lower pressing force. However, this parameterdoes not have an obvious effect on the effective strain magnitude and strain dispersaluniformity. Furthermore, the highest imposed effective strain, the best straindistribution homogeneity and the lowest required punch load were achieved for the deformedmaterial with the lowest strength coefficient and highest strain-hardening exponent.

A model has been developed to describe the rheology of austenite at high temperatures, characteristic from hot strip rolling of low-alloyed steels. It is based on the evolution of a single dislocation density through storage and strain rate-dependent dynamic recovery. The model gives good predictions of the stress-strain curves in a wide range of temperatures, strain rates and chemical compositions. It is now applied on industrial hot strip mills to predict the rolling loads of a wide range of industrial steels.

In this paper, the effect of an annealing treatment on the microstructure, mechanicalproperties and electrical conductivity of a deformed Cu-12.8 wt%Fe composite prepared bythe “casting/cold working” process is investigated. The Fe filaments exhibit the shapecharacteristic in the as-drawn composite as the annealing temperature is lower than 500°C. When the annealing temperature is above 500 °C, the Fe filaments undergo theinstability process in terms of boundary splitting, coarsening and breakup gradually. Thetensile strength gradually decreases with increasing annealing temperature due to thecoarsening of filament spacing. The work hardening for the composite annealed above 600 °Cis slower than that annealed at a lower temperature. The electrical conductivity reaches amaximum of 60%IACS at a temperature of 450 °C for one hour of annealing, and it furtherincreases with increasing annealing time at 450 °C to reach a plateau of 68% IACS. Thecurve between the tensile strength and electrical conductivity under different annealingprocesses indicates that the optimum annealing temperature for the Cu-Fe composite is 450°C.

Amorphous alloys have high tensile strength and easy soft magnetization, and are corrosion-resistant. As conventional amorphous alloy strips are mainly produced by the single rolling method, their thickness is less than 100 µm and their width is less than 200 mm. By combining ultra-rapid cooling, large-scale thermal spraying and warm rolling, the world’s first ever amorphous alloy strips were produced with thickness exceeding 300 µm and width exceeding 300 mm.

L’acier inoxydable 304L est utilisé dans de nombreux domaines. Cependant, il peut, dans certaines conditions, être sensible à la corrosion par piqûration. Dans cette étude, nous nous sommes intéressés aux potentialités du traitement de fusion superficielle par laser nanopulsé pour l’amélioration de la résistance à la corrosion de cet acier. Ce traitement consiste à focaliser un faisceau laser sur la surface du matériau, provoquant sa fusion quasi instantanée sur quelques microns, immédiatement suivie d’un refroidissement ultra-rapide allant jusqu’à 1011 K/s. Les paramètres laser impliquent des modifications des propriétés physico-chimiques. Nous avons notamment étudié l’influence du recouvrement des impacts d’un laser à fibre ytterbium sur la résistance à la corrosion de l’acier inoxydable 304L dans des conditions d’une solution aérée, agitée de NaCl (concentration de 30 g/L). Nous avons obtenu une augmentation du potentiel de piqûration de l’ordre de 220 mV, traduisant une amélioration de la résistance à la corrosion. L’étude approfondie des modifications chimiques et structurales ne suffisent pas à elles seules à expliquer l’amélioration de la résistance à la corrosion. D’autres phénomènes doivent être pris en compte, comme la qualité de la couche d’oxyde, tant en terme de propriétés physico-chimiques, que mécaniques.

Especially in OECD countries, the reduction of primary energy consumption is a major taskto avoid further increase in CO2 emissions. Since 37% of the annual energyconsumption is related to the building sector, it is a major challenge for the future todevelop methods for significant improvement of the energy efficiency of building design,construction and operation. It has to be noted that the development of sustainablebuildings addresses both engineering and social aspects. From an engineering viewpointmethods to improve the ecologic efficiency of buildings by increasing the lifetime have tobe provided. From a social viewpoint these new approaches must take the future needs ofsociety into consideration. In addition, also governance structures and the regulatoryframework for the construction and operation of buildings need to be modified in thedirection of sustainability. The article will initially identify the major research topicsfor the development of sustainable design principles for buildings. Afterwards, structuralrequirements will be defined and translated into required property profiles for buildingmaterials. Herein, both mechanical and functional properties are of importance, so thatapproaches will be presented how to combine these properties in composite buildingmaterials. With respect to mechanical properties, new steels will have to be developedwith an improved balance of strength and ductility, so that some promising steel designconcepts will be shown. Additionally, new approaches for the failure assessment of thesenew steel types will be presented to enhance the exploitation of the characteristics ofthe innovative materials.

Simulation experiments were conducted to identify the dominant factors that affect topdross generation in metal coating baths. From the experiments and the microstructuralanalyses of the top dross, it is proposed that top dross is generated through bath metalentrainment by the oxide film and subsequent drainage during holding. A new concept,taking into consideration the fresh area creation during the wiping process, is introducedand a mathematical model is developed to quantify dross generation in the metal coatingprocess. From the proposed mechanism, a new metric is developed to quantify top drossgeneration in the coating bath. The experimental results agree well with both theoreticalresults and production data of galvanising (GI) baths based on this metric.

Cette étude expérimentale présente de nouveaux matériaux composites développés récemmentpour le brasage de pièces en cuivre. Il s’agit de compositions à base d’agarose quipeuvent être mises en forme par moulage par injection de poudres. Cette facilité de miseen œuvre ouvre comme possibilité d’application la fabrication de préformes de brasage deformes complexes. Deux exemples d’utilisations sont présentés, l’un porte sur le brasagetendre et l’autre concerne le brasage fort. Les brasures finales obtenues permettentd’obtenir une résistance mécanique et une qualité métallurgique similaires à cellesobtenues à partir des matériaux conventionnels (bases SnPb ou CuP) utilisés pour lebrasage manuel de tubes en cuivre.

The goal of this study is to empirically investigate the major hot rolling processparameters affecting the yield strength, ultimate tensile strength and strain-hardeningexponent of Nb-microalloyed steel sheets. The parameters considered were the roughing,finishing and coiling temperatures. Three levels for each parameter were used to develop amodel relating the process parameters to mechanical properties. By applying the responsesurface methodology, analysis of variance was done to determine the mathematical modelsrelated to each response. The results indicated that decreasing the coiling and finishingtemperatures significantly influenced the mechanical properties. Also, the modelspredicted that the maximum yield strength, ultimate tensile strength and strain-hardeningexponent are simultaneously obtained under the following conditions: roughing temperature= 1097 °C, finishing temperature = 837 °C and coiling temperature = 580 °C. The predictedvalues were close to the experimental values, indicating the suitability of themodels.

Concerns for climate change and declining oil reserves lead to a shift of transportationsystems in many industrial countries. However, alternative drive concepts contain to someextent critical raw materials. Since the availability of certain raw materials could bedecisive for the success of emerging technologies, concerns are growing about thepotential limitation of resources. This brought about a growing attention to the subjectsof criticality and resource security of raw materials by science, policy and industry.Four of the resulting surveys are described in terms of their framing of criticality,their indicators for evaluating criticality, and their rankings of potentially criticalraw materials. Critical raw materials are used in alternative drive concepts because oftheir specific properties. The focus of our work lies on batteries for electric vehicleswith special attention to lithium-ion batteries being one of the most promising candidatesfor energy storage there. Lithium-ion batteries use as major cathode materials lithium,manganese and cobalt, all of which are potential critical. A material flow model of theglobal manganese cycle is developed. It could be identified that there is a lack ofrelevant data for processes and flows. The lack of data impedes a comprehensive view andtherefore no final conclusions could be drawn, which advice the need for further research.Using manganese as an example, it could be illustrated how material flow analysis cancontribute to compiling relevant preparatory work that can subsequently serve as a basisfor a prospective support of a criticality evaluation and to inform stakeholders andpolicy makers about the effectiveness of various interventions to reduce the risk or theeffects of supply chain disruptions.

The challenges of sustainable urban development are tremendous. More than half of the earth’s population lives in cities and there is an upward trend. On a global scale, the cities are the greatest greenhouse gas producers and the biggest consumers of water and energy. Urbanisation, climate change and demographic change are forcing metropolises to make their infrastructure more efficient, be environmentally friendlier, keep the high standard of living and if possible save costs. One of the keys is the selection of materials. Buildings are responsible for 40% of the energy consumption and approx. 21% of produced CO2 worldwide. Scientists and researchers from all over the world are looking into new technologies, so that energy could be used efficiently and CO2 emissions reduced, without having to pass on comfort or “lifestyle habits” [http://www.siemens.de/nachhaltige-stadtentwicklung/nachhaltige-stadtentwicklung.html?stc=deccc020187 (accessed 27.04.2012)]. Sustainability is a complex term, used in the last 2–3 decades. It involves more than just the environment and it concerns every one of mankind [cf. Schlussbericht der Enquete-Kommission Globalisierung der Weltwirtschaft – Herausfordeung-en und Antworten, Drucksache 14/9200, http://dipbt.bundestag.de/dip21/btd/14/092/1409200.pdf, p. 393]. This is why social and engineering scientists from RWTH Aachen University have joined in their efforts to figure out how used shipping containers, which are in abundant supply, can play their role in the future of sustainable construction. After they have been used several times, freight containers are considered disused and begin to accumulate in the surroundings of seaports and harbours. The energy to produce a container is significant and considered wasted if the steel box has completed only a few runs. The first association with containers can be a cold and uncomfortable cell, however, after a glance at the properly adapted shipping containers, converted into cosy, pretty and affordable habitable spaces, this preconception can soon be dismissed. Research has shown, in terms of environment and design, they are innovative and intelligent – building with cargo containers is cheaper, “greener”, faster and more flexible than traditional methods. With the increase of life expectancy and population continuing to grow, demand for housing will rise as well. Demographic change and the demand will contribute to rising construction prices. Habitation is one of the essential basic needs of all people. If one takes into account population growth and the timely provision of housing for all people, existing construction methods have to be adapted and new ones developed. Space in the social sense is an expression of the society and not its reflexion [cf. M. Castells, The Rise of Network Society, Wiley-Blackwell, 2010, p. 440f]. Bearing in mind the diversity in Europe’s population and the anxiety for environmental protection and sustainability, also the contrariness in environmental awareness and behavior, likewise eco-friendly and polluting habits in our everyday life, which are linked together in a various and unconsidered way, validates having different levels of environmental awareness depending on the different segments of society. We speak here of the “patchwork” – character of lifestyles and values, which is illustrated and explained easily with the Sinus-Milieu-Model [Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit, Umweltbewusstsein in Deutschland 2010, Ergebnisse einer repräsentativen Bevölkerungsumfrage, 2010, p. 13]. This paper discusses the existing Sinus-Milieus® [http://www.sinus-institut.de/en/ (accessed 27.04.2012)] and their features and show hereupon the growing demand in the society on flexible living concepts and habitat designs. The theory supports, that building with steel containers could be a real solution for the social and environmental problems. A continuously availability of shippingcontainers as a building block is expected and therefore the construction business with steel containers has a great potential in terms of sustainability towards a sustainable construction in a sustainable city.

Les plus grands gisements technogènes des métaux de platine du monde sont situés dans la région industrielle de Norils. Ils se sont formés pendant plusieurs décennies lors du traitement des minerais de sulfure de cuivre-nickel de l’usine Norilsk nickel (Mining and Metallurgical Company Norilsk nickel, MMC NN). Dans cette usine, se sont accumulés au fil du temps plus de 300 millions de tonnes de résidus technogènes secs, qui constituent une source prometteuse de métaux précieux. Il est à noter que tous les principaux producteurs mondiaux de MPG (les métaux du groupe du platine) possèdent des dépôts de résidus technogènes de diverses importances, mais les plus grands gisements technogènes de platine sont liés uniquement aux secteurs d’exploitation minière et métallurgique russe. La nécessité du développement du complexe de production des métaux de platine russe et du renforcement de sa position sur le marché mondial de MPG est conditionnée à la rationalité de l’élaboration d’une technologie de traitement de matières premières technogènes efficace et sûre pour l’environnement.

The increasing proportion of renewable resources in electricity mixes, thedecentralization of energy supply and the growing use of electric vehicles demands thechallenging development of reliable, cost effective and flexible energy storagetechnologies. One option are electrochemical energy storage systems with high specificpower and high specific energy density. One of the most promising electrochemical energystorage systems is the lithium-ion batteries (LIB) which are customized regarding size,weight, specific energy and specific capacity what makes batteries ready for operationunder different conditions such as emerging electric power systems, grid support orelectric mobility [1]. Even though the lithium-Iontechnology for traction batteries is not yet widely applied, experiments and first useexperiences show that it is a promising electric energy storage system for electricmobility. However, the environmental impacts of battery production, use and recycling arenot well understood. To gain a better understanding about the ecological properties ofLIBs material and energy flow analysis (MEFA) is conducted. The MEFA defines the possiblesources and consumers of relevant materials, substances, pollutants and energy flows[2, 3]. Thepresented study analyses the consumed materials and energy as well as the emittedsubstances and waste heat of different LIBs. The main focus of the MEFA is on theproduction phase and includes active and passive components and material such asmetal-salts, electrode materials, other functional metals (e.g. current collectors,casing, etc.), plastics (e.g. separator) and electrolytes [4--7] and on energy consumption aswell.

The year of 2012 marks the 20th anniversary since the concept of ecological footprint was introduced to the global community for the first time. Nowadays footprint studies have gained extensive debates as well as popularity. In this paper, we define the footprint family as an indicator system of selected footprints that measure some aspects of human impacts on the environment. A relatively comprehensive introduction and comparison of four key footprints is represented by listing their characteristics in different aspects. The interaction among these footprints within the footprint family is classified into three types: overlap, contradiction and complement. The description of each type is provided in detail. Limitations and uncertainties of the footprint family, and priorities for further improvement are also performed. This research makes a preliminary attempt at developing the conceptual framework for the footprint family, which allows us to examine the performance of footprints combination. The footprint family will serve as a tool for integrating footprints on human impacts assessment, and a support for environmental decision-making.

Emergy evaluation (EME) is an environmental assessment method which isgaining international recognition and has increasingly been applied during the lastdecade. Emergy represents the memory of the geobiosphere exergy(environmental work) – measured in solar emjoules (seJ) – that has beenused in the past or accumulated over time to make a natural resource available. Therationale behind the concept of Emergy is the consideration that alldifferent forms of energy can be sorted under a hierarchy and measured with the commonmetric of the seJ, which is then the yardstick through which all energy inputs and outputscan be compared with each other. For this reason EME is suggested to be a suitable methodof environmental accounting for a wide set of natural resources, and can be used to defineguidelines for sustainable consumption of resources. Despite those interesting features,EME is still affected by several drawbacks in its calculation procedures and in itsgeneral methodological background, which prevent it from being accepted by a widercommunity. The main operational hurdle lays in the set of mathematical rules (known asEmergy algebra rules) governing EME, which do not follow logic ofconservation and make their automatic implementation very difficult. This work presents anopen source code specifically created for allowing a rigorous Emergycalculation (complying with all the Emergy algebra rules). Wemodeled the Emergy values circulating in multi-component systems with anoriented graph, formalized the problem in a matrix-based structure and developed a variantof the well-known track summing algorithm to obtain the totalEmergy flow associated with the investigated product. The calculationroutine (written in C++) implements the Depth First Search (DFS) strategy for graphsearches. The most important features of the calculation routine are: (1) its ability toread the input in matrix form without the need of drawing a graph; (2) its rigorousimplementation of the Emergy rules; (3) its low running time, which makesthe algorithm applicable to any system described at the level of detail nowadays madepossible by the use of the available life cycle inventory (LCI) databases. A version ofthe Emergy calculation routine based on the DFS algorithm has beencompleted and is being tested on case studies involving matrices of thousands of rows andcolumns, describing real product production systems.

Materials have been invented by mankind in the course of prehistory and history and have evolved during this long period of time to fit the parallel changes in technological epistemes. Materials, therefore, have been a cumulative technological commodity, because of the continuity that this mechanism of change has ensured Structural materials, of which all anthropogenic artefacts are made and with which they are made (machines, process tools, etc.), have been more especially enduring and have carved themselves specific roles in our world that survive across major paradigm shifts and Kondratief cycles. Materials are analyzed here in terms of their physico-chemical nature (or physio-chemical in the case of natural, renewable materials) and of their footprints on energy consumption and greenhouse gas emissions, two of the major lenses through which the sustainability of our economic world is presently observed. The picture that comes out of this examination is that of complementarity and cooperation between materials, with competition acting as a sting to avoid a slack in technology but no pushing any of them out of their market, at least globally. This cohabitation, akin to a natural selection mechanism in a global ecosystem, may be the real driver of dematerialization, a trend which population growth and urbanization forces on mankind.