References of "Mertens, Anne"
     in
Bookmark and Share    
Full Text
See detailTechniques additives vs techniques conventionnelles-les microstructures
Mertens, Anne ULg; Lecomte-Beckers, Jacqueline ULg

Conference given outside the academic context (2014)

Très flexibles et particulièrement bien adaptées à la production de petites séries, les techniques additives suscitent un intérêt croissant, notamment pour la mise en oeuvre de matériaux métalliques. Par ... [more ▼]

Très flexibles et particulièrement bien adaptées à la production de petites séries, les techniques additives suscitent un intérêt croissant, notamment pour la mise en oeuvre de matériaux métalliques. Par-delà la diversité des techniques que ce terme recouvre (laser beam melting, electron beam melting, laser cladding…) et par-delà la variété des alliages qu’elles permettent de mettre en oeuvre, quelques caractéristiques récurrentes se dessinent: 1) La nature fortement directionnelle des procédés additifs, lié au fait que la pièce est fabriquée “couche par couche” 2) Des cycles de chauffe et de refroidissement ultra-rapides, en fonction des déplacements du/des faisceau(x) La présente communication s’attache à illustrer ces deux caractéristiques essentielles des techniques additives au moyen d’exemples touchant aux principaux alliages métalliques (aciers, alliages d’aluminium ou de titane…), et à en dégager les risques et les opportunités qu’offrent les techniques additives du point vue du contrôle et de l’optimisation des microstructures et des propriétés d’usage qui en découlent… [less ▲]

Detailed reference viewed: 26 (7 ULg)
Full Text
Peer Reviewed
See detailMechanical properties of alloy Ti-6Al-4V and of stainless steel 316L processed by Selective Laser Melting: Influence of out-of-equilibrium microstructures
Mertens, Anne ULg; Reginster, Sylvie ULg; Paydas, Hakan ULg et al

in Powder Metallurgy (2014)

Ti-6Al-4V and stainless steel 316L have been processed by selective laser melting under similar conditions, and their microstructures and mechanical behaviours have been compared in details. Under the ... [more ▼]

Ti-6Al-4V and stainless steel 316L have been processed by selective laser melting under similar conditions, and their microstructures and mechanical behaviours have been compared in details. Under the investigated conditions, Ti-6Al-4V exhibits a more complex behaviour than stainless steel 316L with respect to the occurrence of microstructural and mechanical anisotropy. Moreover, Ti-6Al-4V appears more sensitive to the build-up of internal stresses when compared with stainless steel 316L, whereas stainless steel 316L appears more prone to the formation of “lack of melting” defects. This correlates nicely with the difference in thermal conductivity between the two materials. Thermal conductivity was shown to increase strongly with increasing temperature and the thermophysical properties appeared to be influenced by variations in the initial metallurgical state. [less ▲]

Detailed reference viewed: 54 (2 ULg)
Full Text
See detailFriction Stir Processing of Magnesium Matrix Composites Reinforced with Carbon Fibres or Carbon Nanotubes - A Comparative Study
Mertens, Anne ULg; Simar, Aude; Garray, Didier et al

Conference (2013, December 05)

The poor wettability of carbon substrates by liquid Mg and, in the case of carbon nanotubes (CNTs), their strong tendency to agglomerate, are major obstacles to the large-scale production of C-Mg ... [more ▼]

The poor wettability of carbon substrates by liquid Mg and, in the case of carbon nanotubes (CNTs), their strong tendency to agglomerate, are major obstacles to the large-scale production of C-Mg composites by classical ‘liquid-state’ processing routes such as squeeze casting. As an innovative ‘solid state’ process, Friction Stir Processing (FSP) hence appeared as a very promising alternative for the production of C-Mg composites, although the method for inserting the reinforcing phase - in grooves or holes machined in the matrix material - remained time-consuming and labour-intensive. More recently, the present authors proposed a new and easier technique for the insertion of C fibres in FSPed Mg-matrix composites i.e. FSP of a C fabric stacked between two metal sheets. In the current work, the feasibility of extending this latter method to the production of CNTs-Mg composites has been assessed. “Bucky papers” – thin disks made from agglomerated CNTs, thus ensuring for their safe handling – were stacked between two sheets of Mg alloy AZ31B, and the resulting sandwich was FSPed. The effect of FSP experimental parameters such as the rotational and advancing speeds or the number of passes on the microstructural changes occuring upon processing has been studied and compared with the case of C fibres-Mg composites. Moreover, a particular attention has been given to the distribution of the reinforcements in the Mg matrix and to the characterization of the resulting mechanical properties. [less ▲]

Detailed reference viewed: 37 (3 ULg)
Full Text
See detailMeasuring the thermophysical properties of materials at high temperature - Application to the additive manufacturing of alloy Ti-6Al-4V and of stainless steel 316L
Mertens, Anne ULg; Paydas, Hakan ULg; Reginster, Sylvie ULg et al

Conference (2013, November 07)

In view of optimising the microstructures of metallic materials and obtaining the desired properties, the accurate characterisation of the thermophysical behaviour of these materials has long been ... [more ▼]

In view of optimising the microstructures of metallic materials and obtaining the desired properties, the accurate characterisation of the thermophysical behaviour of these materials has long been considered of paramount importance e.g. by allowing for the in-situ study of phase transformations, by providing data for numerical simulations and, essentially, by contributing to a better understanding of the fundamental mechanisms at play during processing. In the present work, the thermophysical behaviour of Ti-alloy Ti-6Al-4V and of stainless steel 316L has been characterised in details, in order to reach a better understanding of the phenomena controlling the microstructures and mechanical properties of parts made by additive manufacturing techniques that appear nowadays very promising in view of the economic production of near-net-shape, complex and (almost) fully dense parts from metallic materials. In particular, the thermal conductivity of Ti-alloy Ti-6Al-4V and of stainless steel 316L at high temperature has been determined by combining dilatometry, Differential Scanning Calorimetry (DSC) and laser flash diffusivimetry based on Laplace’s equation : k(T)=α(T)ρ(T)Cp(T) where k(T) is the thermal conductivity (W/m*K) α(T) is the thermal diffusivity (mm2/s) ρ(T) is the specific mass (g/cm3) Cp(T) is the specific heat capacity (J/g*K). Since Ti-alloy Ti-6Al-4V and stainless steel 316L exhibit quite different physical behaviours, their careful comparison is shown to shed more light into the role of phenomena such as epitaxial growth, out-of-equilibrium phase transformations and/or internal stresses in the additive manufacturing of metallic materials. [less ▲]

Detailed reference viewed: 91 (22 ULg)
Full Text
See detailLes matrices métalliques et céramiques : de nouveaux matériaux composites
Montrieux, Henri-Michel ULg; Lecomte-Beckers, Jacqueline ULg; Mertens, Anne ULg

in Plus Composites (2013), article n°3

Le présent article décrit différentes limitations des matériaux composites à matrice polymère. Outre l’amélioration de la formulation des résines, une des alternatives qui se présente est d’employer une ... [more ▼]

Le présent article décrit différentes limitations des matériaux composites à matrice polymère. Outre l’amélioration de la formulation des résines, une des alternatives qui se présente est d’employer une matrice métallique ou céramique. Certains de ces matériaux nouveaux sont toujours au stade du développement. Il s’agit par exemple des composites pour applications structurales avec une matrice légère en aluminium ou en magnésium pour lesquels les rapports rigidité-poids et résistance-poids sont élevés. La résilience est aussi améliorée par rapport aux matrices classiques simplement renforcées. D’autres composites à matrice métallique tels que les cermets sont industrialisés comme outils de coupe. Des composites à matrice céramique comme le carbone-carbone ou le carbone-SiC peuvent être industrialisés et présentent une durabilité et une température d’utilisation maximale exceptionnelle. Pour terminer, l’article fournit quelques informations sur les techniques nouvelles de mise à forme des matériaux composites telles que le friction stir processing et l’additive manufacturing. [less ▲]

Detailed reference viewed: 28 (2 ULg)
Full Text
See detailOn the Role of Out-of-Equilibrium Microstructures in Ti-6Al-4V and in Stainless Steel 316L Processed by Selective Laser Melting in Determining their Mechanical Properties
Mertens, Anne ULg; Reginster, Sylvie ULg; Paydas, Hakan ULg et al

Conference (2013, September 12)

Additive manufacturing processes such as Selective Laser Melting (SLM) appear very promising in view of the economic production of near-net-shape, complex and (almost) fully dense parts from metallic ... [more ▼]

Additive manufacturing processes such as Selective Laser Melting (SLM) appear very promising in view of the economic production of near-net-shape, complex and (almost) fully dense parts from metallic materials such as Ti alloys and stainless steels. Practically, in SLM, a metallic powder is deposited layer-by-layer in a powder bed and then molten locally according to the desired shape. An important feature of this process is that the structure undergoes an ultra-fast cooling once the beam leaves the working zone, thus giving rise to strongly out-of-equilibrium microstructures. In the case of Ti alloy Ti-6Al-4V, in particular, the microstructural anisotropy resulting from the epitaxial growth of the newly deposited layer on the material previously solidified has been shown to exert a very strong influence on the mechanical properties [1]. In the present work, the microstructures and mechanical properties of Ti-6Al-4V and of stainless steel 316L processed by SLM have been characterised in details. Since these two materials exhibit quite different physical behaviours, their careful comparison might shed more light into the role of phenomena such as epitaxial growth, out-of-equilibrium phase transformation and/or internal stresses in determining the mechanical properties of metallic parts processed by SLM. [less ▲]

Detailed reference viewed: 54 (9 ULg)
Full Text
See detailMicrostructure and Thermomechanical Behaviour of Magnesium – C nanotubes Composites produced by Friction Stir Processing
Mertens, Anne ULg; Simar, Aude; Garray, Didier et al

Conference (2013, September 09)

Due to their exceptional mechanical and thermal characteristics, C nanotubes (CNTs) are attracting an ever increasing interest in view of tailoring the properties of metal matrix composites (MMCs) e.g ... [more ▼]

Due to their exceptional mechanical and thermal characteristics, C nanotubes (CNTs) are attracting an ever increasing interest in view of tailoring the properties of metal matrix composites (MMCs) e.g. for applications at high service temperature or in thermal management… However, the poor wettability of CNTs by molten metals and their strong tendency to agglomerate are major obstacles to the large-scale production of CNTs-MMCs by classical ‘liquid-state’ processing routes such as squeeze casting. As an innovative ‘solid state’ process, Friction Stir Processing (FSP) hence appears as a very promising alternative for the production of CNTs-MMCs [1], although the method for inserting the reinforcing phase - in grooves or holes machined in the matrix material - remains time-consuming and labour-intensive. More recently, Mertens et al. [2] proposed a new and easier technique for the insertion of C fibres in FSPed Mg-matrix composites i.e. FSP of a C fabric stacked between two metal sheets. In the present work, the feasibility of extending this latter method to the production of CNTs-MMCs has been assessed. “Bucky papers” – made from agglomerated CNTs, thus ensuring for their safe handling – were stacked between two sheets of Mg alloy AZ31B, and the resulting sandwich was FSPed. The effect of FSP experimental parameters such as the rotational and advancing speeds, and the number of FSP passes, on the microstructure of the composites and particularly on the distribution of the CNTs in the Mg matrix has been carefully studied. Moreover, a particular attention has been given to the characterization of the thermomechanical behaviour of the FSPed AZ31B-CNTs composites. [less ▲]

Detailed reference viewed: 25 (2 ULg)
Full Text
See detailComparison between optical pulsed thermography and vibrothermography for the assessment of carbon fibers composite materials
Montrieux, Henri-Michel ULg; Demy, Philippe; Ibarra-Castanedo, Clemente et al

Scientific conference (2013, August 02)

Pulsed thermography and vibrothermography are two active thermography techniques characterized by different heating methods of the specimen. In pulsed phase thermography, a sample is heated by two flash ... [more ▼]

Pulsed thermography and vibrothermography are two active thermography techniques characterized by different heating methods of the specimen. In pulsed phase thermography, a sample is heated by two flash lamps for a short period to inject a Dirac impulse heat in the material. The cooling of the part is monitored with an infrared camera to detect thermal contrast in the image, characteristic of the presence of a defect. In vibrothermography, high frequency vibrations are injected into the sample causing an internal heating observed on surface right above the defect due to diverse phenomena as friction or viscoelastic hysteresis. If pulsed thermography is a well-known technique that has been integrated into the arsenal of industrial NDT methods, vibrothermography is a less common experimental method still subject to theoretical and practical investigations. This article aims to compare the effectiveness of the two methods in the case of different types of composites based on carbon fibers: carbon fiber reinforced plastic (CFRP) plates as well as a completely new material: carbon magnesium composite. [less ▲]

Detailed reference viewed: 33 (3 ULg)
Full Text
Peer Reviewed
See detailProcessing of Ti alloys by additive manufacturing: a comparison of the microstructures obtained by laser cladding, selective laser melting and electron beam melting
Reginster, Sylvie ULg; Mertens, Anne ULg; Paydas, Hakan ULg et al

in Materials Science Forum (2013), 765

Additive manufacturing processes such as laser cladding (LC) or selective laser melting (SLM) appear very promising in view of an economic near-net-shape production – and also, in the case of LC, the ... [more ▼]

Additive manufacturing processes such as laser cladding (LC) or selective laser melting (SLM) appear very promising in view of an economic near-net-shape production – and also, in the case of LC, the restoration - of complex and (almost) fully dense parts from Ti alloys. Both techniques involve the melting of a metallic powder with a laser. In the SLM process, the metallic powder is deposited layer by layer in a powder bed and then molten locally according to the desired shape, whereas in LC, the metallic powder is directly projected onto a substrate through a nozzle coaxial with the laser beam. The present research aims at comparing Ti-6Al-4V samples processed by these two techniques with reference samples produced by electron beam melting (EBM), another well established additive manufacturing process (patented by Arcam AB Company) in which a powder bed is molten locally by means of an electron beam. In all three processes, the melt pool undergoes an ultrafast cooling and solidifies very rapidly once the beam has left the area, thus giving rise to strongly out-of-equilibrium microstructures. Yet, each one of these processes also has its own specificities e.g. in terms of scanning strategy and of working atmosphere (low vacuum vs. protective Ar flow). In the present work, the microstructures obtained by these three processes have been compared in details, with a particular attention for characteristics such as porosity, grain size, and the various phases present. Since epitaxial growth of the newly deposited layer on the material previously solidified has been shown [1, 2] to exert a strong influence on the microstructure and on the resulting mechanical properties, great care has been taken to study the microstructural anisotropy associated with each one of the three processes. [less ▲]

Detailed reference viewed: 296 (56 ULg)
Full Text
See detailDéveloppement d’une ailette d’obus en composite magnésium renforcé de fibres de carbone
Montrieux, Henri-Michel ULg; Mertens, Anne ULg; Lecomte-Beckers, Jacqueline ULg

Report (2012)

This report describes the accomplished breakthrough for the manufacturing of long carbon fibres reinforced magnesium alloy (AZ91). Infiltration can be performed with non-equilibrium conditions such as ... [more ▼]

This report describes the accomplished breakthrough for the manufacturing of long carbon fibres reinforced magnesium alloy (AZ91). Infiltration can be performed with non-equilibrium conditions such as fibres preheating, high liquid compacting pressure and low contact times. Thanks to specific TEOS sol/gel treatment, the reached fibre rate is 60 vol.% and the measured Young's modulus of the composite is ca. 110 GPa. The presence of defects including fibre yarns misorientation, unreinforced areas seems very detrimental to the bending properties. Other advanced infiltration techniques with Al pretreatment (K2ZrF6) of fibres is also considered. [less ▲]

Detailed reference viewed: 30 (4 ULg)
See detailInfluence of Fiber Distribution and Grain Size on the Mechanical Behavior of Friction Stir Processed Mg-C Composites
Mertens, Anne ULg; Montrieux, Henri-Michel ULg; Lecomte-Beckers, Jacqueline ULg et al

Conference (2012, November 12)

Short C fibers-Mg matrix composites have been produced by friction stir processing sandwiches made of a layer of C fabric stacked between two sheets of either the ductile Mg alloy AZ31B, or of the less ... [more ▼]

Short C fibers-Mg matrix composites have been produced by friction stir processing sandwiches made of a layer of C fabric stacked between two sheets of either the ductile Mg alloy AZ31B, or of the less ductile alloy AZ91D, that is capable of age hardening. It has been shown that the choice of the optimal experimental parameters for the production of sound composites was strongly dependent on the nature of the matrix. 3D X-ray tomography reveals that the fibers orient along the onion rings and that they are more or less fragmented depending on the local shear stress during the process. The fiber volume fraction is increased when the nugget volume decreases in particular for the AZ91D base material and for a high advancing speed for the AZ31B base material. The fiber volume fraction influences directly the grain size, the hardness and the tensile properties of the composites. [less ▲]

Detailed reference viewed: 38 (7 ULg)
See detailComposite Manufacturing by Friction Stir Processing
Simar, Aude; de Meester, Bruno; Delannay, Francis et al

Conference (2012, October 29)

A new solid-state process developed recently on the same principles as Friction Stir Welding (FSW), Friction Stir Processing appear as a very promising technique for the production of metal matrix ... [more ▼]

A new solid-state process developed recently on the same principles as Friction Stir Welding (FSW), Friction Stir Processing appear as a very promising technique for the production of metal matrix composites and for tailoring materials properties. In the present work, this process has been applied to two different composite systems: (i) magnesium-matrix composites reinforced with carbon fibers, and (ii) copper-matrix composites reinforced with Y2O3 powder. Process optimization and mechanical properties of the composites are discussed in both systems. [less ▲]

Detailed reference viewed: 60 (4 ULg)
Full Text
See detailExperimental Characterisation of Damage Occuring during Single Point Incremental Forming of a Ferritic Steel
Mertens, Anne ULg; Guzmán Inostroza, Carlos Felipe ULg; Habraken, Anne ULg et al

Poster (2012, September)

Single Point Incremental Forming (SPIF) has been developed as a new dieless process for forming metal sheets. This technique appears very promising in view of the current requirements for rapid ... [more ▼]

Single Point Incremental Forming (SPIF) has been developed as a new dieless process for forming metal sheets. This technique appears very promising in view of the current requirements for rapid prototyping and/or small series production [1]. However, inaccuracies in the shape of the processed part and material failure constitute important limiting factors for applications. In the present research, a numerical approach, based on the damage model proposed by Gurson [2], has been chosen to analyse and optimise the process, predict the material rupture and the process limit. From experimental observations of plastic deformation and ductile fracture, damage is related to the nucleation, growth and coalescence of microvoids [3]. Gurson’s model uses the volume fraction of these voids as a main variable. Hence the determination of this value is a key factor for a correct identification and validation of the model. More particularly, the present work focuses on two different methods used to experimentally characterise damage occurring during single point incremental forming of a ferritic steel. Void measurements carried out by optical microscopy combined with image analysis have been compared with porosity values obtained from density measurements based on the Archimedes’ principle [4], so as to assess the feasibility of using this method for a quick characterisation of the damage. [less ▲]

Detailed reference viewed: 84 (33 ULg)
Full Text
Peer Reviewed
See detailFriction Stir Processing of Magnesium Matrix Composites reinforced with Carbon Fibres: Influence of the Matrix Characteristics and of the Processing Parameters on Microstructural Developments
Mertens, Anne ULg; Simar, Aude; Montrieux, Henri-Michel ULg et al

in W.J.Poole, K.U.Kainer (Ed.) Proceedings of the 9th International Conference On Magnesium Alloys and their Apllications (2012, July 12)

Processing of magnesium matrix composites reinforced with C fibres by ‘liquid state’ methods such as squeeze casting are usually impaired by the poor wettability of C substrates by liquid Mg. As a ... [more ▼]

Processing of magnesium matrix composites reinforced with C fibres by ‘liquid state’ methods such as squeeze casting are usually impaired by the poor wettability of C substrates by liquid Mg. As a consequence, ‘solid state’ processes such as Friction Stir Processing (FSP) appear as very promising alternative processing routes for the production of C-Mg composites. And, more particularly, FSP of a C fabric between two sheets of the fairly ductile Mg alloy AZ31B was shown to be a simple and innovative process for a large-scale production of magnesium matrix composites reinforced with short C fibres. In the present work, FSP of a C fabric between two metal sheets or thin plates has been performed using two different Mg alloys exhibiting quite different mechanical behaviours, i.e. alloy AZ31B and the more brittle alloy AZ91D. And the effect of the matrix characteristics, along with the influence of the FSP experimental parameters such as the rotational and advancing speeds, on the microstructural changes occuring upon processing have been carefully studied. A particular attention has been given to the fragmentation and distribution of the C fibres, as well as to the recrystallisation, solutionising and precipitation processes taking place in the Mg matrix. [less ▲]

Detailed reference viewed: 129 (5 ULg)
Full Text
Peer Reviewed
See detailProcessing of Carbon Fibers Reinforced Mg Matrix Composites Via Pre-infiltration with Al
Mertens, Anne ULg; Montrieux, Henri-Michel ULg; Halleux, Jacques et al

in Journal of Materials Engineering and Performance (2012), 21(5), 701-706

Mg-C composites offer a suitable alternative to Al alloys while allowing for a significant weight reduction, but their production can be impaired by the poor wettability of C substrates by Mg. In the ... [more ▼]

Mg-C composites offer a suitable alternative to Al alloys while allowing for a significant weight reduction, but their production can be impaired by the poor wettability of C substrates by Mg. In the present work, a new 'liquid' processing route has been investigated. By making use of the well-known effect of a pre-treatment of the C fibres with an aqueous solution of K2ZrF6 in favouring spontaneous wetting of C with Al, C yarns have been pre-impregnated with Al and the feasibility of further using them as reinforcements in Mg matrix composites has been assessed. More particularly, it has thus been shown that, under the thermal conditions involved in the process, C fibres did not suffer damage due to chemical reaction with Al, and also that special care should be taken in order to control the surface condition of the pre-infiltrated yarns. [less ▲]

Detailed reference viewed: 22 (7 ULg)
Full Text
See detailTi alloys processed by selective laser melting and by laser cladding: microstructures and mechanical properties
Mertens, Anne ULg; Contrepois, Quentin ULg; Dormal, Thierry ULg et al

in proceedings of 12th EUROPEAN CONFERENCE ON SPACECRAFT STRUCTURES, MATERIALS & ENVIRONMENTAL TESTING, Noordwijk 20-23 mars 2012 (2012, March)

Selective laser melting (SLM) and laser cladding were developed in the late 1990s as economic layer-by-layer near-net-shape processes allowing for the production – and also, in the case of laser cladding ... [more ▼]

Selective laser melting (SLM) and laser cladding were developed in the late 1990s as economic layer-by-layer near-net-shape processes allowing for the production – and also, in the case of laser cladding, the restoration - of complex parts. Both techniques involve the melting of a metallic powder with a laser. In the case of SLM, the metallic powder is deposited layer by layer and then molten locally according to the desired shape, whereas in laser cladding the metallic powder is projected onto a substrate through a tube coaxial with the laser. In both processes, the metallic melt pools then cool down and solidify very rapidly, thus producing strongly out of equilibrium microstructures that might exhibit high internal stresses. In the present work, efforts have been made to enhance the flexibility of the laser cladding process: a second laser with a maximum power of 300W was installed beside the original laser (with a higher maximum power of 2000W), thus allowing for the processing of parts with thinner walls and/or coatings. Moreover, flexibility was also improved in relation with the geometry of the parts by use of a 5-axes displacement control. Samples of alloy Ti-6Al-4V, that is widely used in the aeronautic industry due to its high specific strength, have been processed both by SLM and by laser cladding. The resulting microstructures have been characterised in details by optical microscopy, SEM and EBSD so as to allow for a better understanding of the solidification process and of the subsequent phase transformations taking place upon cooling for both techniques. The influence of processing parameters such as the orientation of the deposition of the successive powder layers on the mechanical properties was also investigated by means of uniaxial tensile testing performed on samples with different deposition orientations in regard to the direction of mechanical solicitation. Moreover, some of the samples for mechanical testing had undergone an annealing treatment at 640°C for 4 hours to relieve internal stresses, in order to assess more precisely the effect of those stresses on the tensile properties. [less ▲]

Detailed reference viewed: 108 (32 ULg)
Full Text
Peer Reviewed
See detailMicrostructure and mechanical properties of stir processed magnesium matrix composites reinforced with carbon fibres
Simar, Aude; Mertens, Anne ULg; Montrieux, Henri-Michel ULg et al

Conference (2012, January 26)

Mg-Al-Zn alloys have been reinforced with carbon fibres using friction stir processing (FSP) which appears as a promising alternative for the large-scale production of C-Mg composites. The process has ... [more ▼]

Mg-Al-Zn alloys have been reinforced with carbon fibres using friction stir processing (FSP) which appears as a promising alternative for the large-scale production of C-Mg composites. The process has shown its ability to produce sound composites with enhanced strength compared to the non-reinforced alloys. The C fabric is fragmented in short fibres leading to a reduction in grain size and an improved hardness. [less ▲]

Detailed reference viewed: 82 (4 ULg)
Full Text
Peer Reviewed
See detailUtilisation et technique de production du fer et du bois dans les charpentes de comble mosanes : premiers jalons d’une évolution du XIIe au XVIIIe siècle
Maggi, Christophe ULg; Pagès, Gaspard; Mertens, Anne ULg et al

in ArchéoSciences (2012), 36

The development of a comparative approach between the evaluation of the quantity of timber used in a roof frame and the volume of wood present in this same attic allows the acquisition of information ... [more ▼]

The development of a comparative approach between the evaluation of the quantity of timber used in a roof frame and the volume of wood present in this same attic allows the acquisition of information about the economical, technical and social contexts in which a timber frame was drawn up. By carrying out this kind of comparison in a systematic way in twenty-tree religious mosan buildings (Belgium and Netherlands), it’s possible to trace, step by step, thanks to dendrochronologic dating of the attics since 12th until 18thcentury, the causes and consequences which influence the methods of constructions of the carpenters. In parallel, the confrontation of this result with the volumes of iron used in the attics reveals the growing importance of this material in function of the time and of the architectural principles. This part of the study was enriched by archeometallurgic analyses intended to identify the process of reduction employed to produce this metal with the aim to measure the possible influence of iron process innovations on the use of iron in the medieval and modern frames, knowing that Wallonia knew from the end of the Middle Ages the early development of the indirect iron process instead of the direct iron process. [less ▲]

Detailed reference viewed: 52 (19 ULg)