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See detailMicrostructural study of high strength rolled Zn-Cu-Ti alloys
Lecomte-Beckers, Jacqueline ULg; Walmag, G.

in Micron and Microscopica Acta (1987), 18(3), 241-242

The aim of the research is to define the microstructure required to obtain the better mechanical resistance after rolling of Zn-Cu-Ti alloys which composition range is 0.78-0.98% (in weight)for Cu and 0 ... [more ▼]

The aim of the research is to define the microstructure required to obtain the better mechanical resistance after rolling of Zn-Cu-Ti alloys which composition range is 0.78-0.98% (in weight)for Cu and 0.12-0.18% (in weight) for Ti. These alloys have been rolled at the VM-AF (Vieille-Montagne - Asturienne France) rolling plant [less ▲]

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See detailMicrostructural study of oxides and carbides used for abrasion properties in high alloyed steels
Lecomte-Beckers, Jacqueline ULg; Magnée, Adrien ULg

in Proceedings of the 8th International Conference on Composites Engineering (2001)

For long applications and for many others, a material with properties between hard metal and high speed steel is necessary. This material should have a high resistance to wear together with good toughness ... [more ▼]

For long applications and for many others, a material with properties between hard metal and high speed steel is necessary. This material should have a high resistance to wear together with good toughness. An attractive solution consists in combining in a composite the properties of a tough ferrous matrix with those of hard reinforced particles. In varying the nature and the proportions of reinforcement and matrix, the properties of the composite can cover many applications. [less ▲]

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See detailMicrostructural study of Zn-11% Al and Zn-27% Al alloys
Lecomte-Beckers, Jacqueline ULg; Terziev, L.; Wegria, J. et al

in Proceedings of the 25th Annual Conference of Metallurgists (1986)

Zinc-aluminium alloys with small amounts of copper and magneisum (ZA alloys) are used in a number of casting processes. They offer the foundry industry a family of zinc alloys with a wide range of ... [more ▼]

Zinc-aluminium alloys with small amounts of copper and magneisum (ZA alloys) are used in a number of casting processes. They offer the foundry industry a family of zinc alloys with a wide range of mechanical properties able to meet a large spectrum of performance criteria. However promising the characteristics of these alloys, microstructural studies of them are incomplete. It has been shown that copper additions to ZA alloys modify the number of the phase existing in the binary zinc-aluminium system as well as their transformation kinetics. Microstructural studies have shown not only the heterogeneity of the microstructure but also the presence of a zinc-rich metastable phase and the evolution of the composition of the ternary phase Zn-Al-Cu (T) during ageing. This situation is not surprising as several studies have shown the existence of metastable phases in the binary system Al-Zn with high aluminium content. the complexity of the microstructure leads us to search further for a better understanding of the binary Zn-Al alloys, with Al contents corresponding to ZA 12 and ZA 27 wihout any Cu and Mg, in order to precise about the complex evolution to stable phases observed in these alloys. [less ▲]

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See detailMicrostructural study of Zn-Al alloy
Terziev, L.; Rashev, P.; Lecomte-Beckers, Jacqueline ULg et al

in Proceedings of The 4th Physics and Chemistry of Solids, School-Symposium Physics of Metals, Polish Academy of Sciences, Institute for Low Temperature and Structure Research (1987)

It is well known that zinc-aluminium alloys posses very good mechanical properties. This is the reason why the investigation of their ageing characteristics is very important for the practice. Several ... [more ▼]

It is well known that zinc-aluminium alloys posses very good mechanical properties. This is the reason why the investigation of their ageing characteristics is very important for the practice. Several solid state reactions between alpha, beta, epsilon and T phases have been established for such materials alloyed with copper, but there has been no detailed on the formation, development and transformation of metastable phases into stable ones. This is exactly the aim of our investigation. [less ▲]

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See detailMicrostructure analyses and thermoelectric properties of Ag1-xPb18Sb1+yTe20
Perlt, S.; Hoeche, Th; Dadda, J. et al

in Journal of Solid State Chemistry (2012), 193(SI), 58-63

This study reports microstructural investigations of long-term annealed 18, x=y=0, hereinafter referred to as AgPb18SbTe20) (Lead-Antimony-Silver-Tellurium, LAST-18) as well as of Ag1-xPb18Sb1+yTe20, i.e ... [more ▼]

This study reports microstructural investigations of long-term annealed 18, x=y=0, hereinafter referred to as AgPb18SbTe20) (Lead-Antimony-Silver-Tellurium, LAST-18) as well as of Ag1-xPb18Sb1+yTe20, i.e. Ag-deficient and Sb-excess LAST-18 (x not equal 0, y not equal 0), respectively. Two different length scales are explored. The micrometer scale was evaluated by SEM to analyze the volume fraction and the number of secondary phases as well as the impact of processing parameters on the homogeneity of bulk samples. For AgPb18SbTe20, site-specific FIB liftout of TEM lamellae from thermoelectrically characterized samples was accomplished to investigate the structure on the nanometer scale. High-resolution TEM and energy-filtered TEM were performed to reveal shape and size distribution of nanoprecipitates, respectively. A hypothesis concerning the structure-property relationship is set out within the frame of a gradient annealing experiment. This study is completed by results dealing with inhomogeneities on the micrometer scale of Ag1-xPb18Sb1+yTe20 and its electronic properties. (C) 2012 Elsevier Inc. All rights reserved. [less ▲]

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See detailMicrostructure and abrasion resistance of tool steels reinforced by dispersed oxides and carbides phases
Magnée, Adrien ULg; Lecomte-Beckers, Jacqueline ULg

in Revue de Métallurgie- Journées d'Automne de la Société Française de Métallurgie et de Matériaux (2000)

Two ferrous matrix, a high speed steel and a maraging steel were reinforced with alumina, titanium and vanadium carbides. The composite was realized by powder metallurgy. The particles were mechanically ... [more ▼]

Two ferrous matrix, a high speed steel and a maraging steel were reinforced with alumina, titanium and vanadium carbides. The composite was realized by powder metallurgy. The particles were mechanically mixed with the prealloyed powder before compaction. To optimize the composite properties, the processing parameters (i.e. prealloyed powders, size, mixing, conditions, temperature of sintering,...) and the effect of reinforcement (size and composition of particles, volume, fraction,...) were studied. It is necessary to obtain full density with minimum porosity and to control the size, distribution and dispersion of the reinforced particles. The optimal sintering temperature depends on the reinforcement particles used and is of great importance for the properties. Processing parameters (mixing of particles) can greatly affect the final properties. The use of AL2O3 was shown to increases wear resistance in the two matrix. [less ▲]

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See detailMicrostructure and durability of mortars modified with medium active blast furnace slag
Hadj Sadok, Ahmed; Kenaï, Saïd; Courard, Luc ULg et al

in Construction & Building Materials (2011), 25(2), 1018-1025

Mechanical characteristics and durability properties of blast furnace slag cement composites largely depend on the hydraulic activity of the slag. In this paper, a Granulated Blast Furnace Slag with a low ... [more ▼]

Mechanical characteristics and durability properties of blast furnace slag cement composites largely depend on the hydraulic activity of the slag. In this paper, a Granulated Blast Furnace Slag with a low reactivity index is used in modifying mortar composition. Microstructure and durability of mixes containing 0%, 30% and 50% of slag as substitution to OPC are respectively compared and analyzed. Water porosity, Mercury Intrusion Porosity and pore size distribution are studied after 28, 90 and 360 days of wet curing. A qualitative microstructure analysis of mortars is proposed with Scanning Electron Microscope (SEM). The durability of mortar is evaluated through capillary water absorption and chloride diffusion tests. The results indicate a finer porosity and lower water absorption for slag mortars at old ages (90 and 360 days). Moreover, lower chloride diffusion for 50% blast furnace slag substitution is observed. [less ▲]

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See detailMicrostructure and Mechanical Properties of a Mixed Si-Al TRIP-Assisted Steel Subjected to Continuous Galvanizing Heat Treatments
Mertens, Anne ULg; Bellhouse, Erika M.; McDermid, Joseph R.

in Materials Science & Engineering : A (2014), 608

Heat treatments with an isothermal bainitic transformation temperature of 465°C compatible with the continuous galvanizing process were performed on a 0.2C-1.5Mn-1.0Si-0.5Al (wt%) TRIP-assisted steel. The ... [more ▼]

Heat treatments with an isothermal bainitic transformation temperature of 465°C compatible with the continuous galvanizing process were performed on a 0.2C-1.5Mn-1.0Si-0.5Al (wt%) TRIP-assisted steel. The effect of intercritical annealing temperature and isothermal bainitic transformation (IBT) time at 465C on mechanical properties and microstructure were determined. The best combination of strength and ductility was obtained for the lower intercritical annealing temperature of 750°C for an isothermal bainitic transformation time of 90 s at 465°C. However, after intercritical annealing at a higher temperature of 797°C, optimum mechanical properties were obtained for a shorter isothermal bainitic transformation time of 60 s at 465°C, likely due to the lower C content of the intercritical austenite bringing about faster transformation kinetics. It was concluded that varying the intercritical temperature and IBT time can play an important role in the development of a suitable process window to obtain the desired mechanical properties in low alloy TRIP-assisted steels given the constraints associated with the continuous galvanizing process. [less ▲]

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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 ▲]

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See detailMicrostructure and properties of PM steel reinforced by dispersed oxides and carbides phases
Lecomte-Beckers, Jacqueline ULg; Magnée, Adrien ULg

in Proceedings of ECCM-8, European Conference on Composite Materials : Science, Technologies and Applications (1998)

Two ferrous matrix, a high speed steel and a maraging steel has been reinforced with alumina, titanium and vanadium carbides. The composite was realized by powder metallurgy.The particles were ... [more ▼]

Two ferrous matrix, a high speed steel and a maraging steel has been reinforced with alumina, titanium and vanadium carbides. The composite was realized by powder metallurgy.The particles were mechanically mixed with the prealloyed powder before compaction. To optimize the composite properties, the processing parameters (i.e. prealloyed powders, size, mixing conditions, temperature of sintering, e..) and the effect of reinforcement (size and composition of particles, volume, fraction, ..) were studied. It is necessary to obtain a full density with the minimum porosities and to control boht the size, the distribution and the dispersion of the reinforced particles. The optimal sintering temperature depends on the reinforcement particles used and is of great importance for the properties. Processing parameters (mixing of particules) can greatly affect the final properties. It has been showed that the use of M203 increases the wear resistance in the two matrix. [less ▲]

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See detailMicrostructure and properties of rapid heat treated and galvanised dual-phase steel
Fourmentin, Richard; Mertens, Anne ULg; McDermid, Joseph R.

Poster (2006, May)

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See detailMicrostructure and Properties of Rapid Heat Treated Galvanized Dual Phase Steels
Fourmentin, Richard; Mertens, Anne ULg; McDermid, Joseph R.

in Proceedings of the MS&T'06 Conference (2006, October)

In order to improve fuel efficiency and reduce greenhouse emissions, the automotive industry has to use more and more advanced high strength steels. Indeed, these steels benefit from both good formability ... [more ▼]

In order to improve fuel efficiency and reduce greenhouse emissions, the automotive industry has to use more and more advanced high strength steels. Indeed, these steels benefit from both good formability and high-energy absorption capacity, and enable manufacturers to reduce the mass of vehicles. To achieve this requirement, refining the non-ferritic phase in steel is a proposed solution. Specifically rapid heat treatment can change the scale and the distribution of the second phase, ameliorating the mechanical properties. However, such heat treated steels, before being used, have to be galvanized to avoid corrosion and maintain the material’s mechanical properties. This study aims to determine the mechanical properties and the galvanisability of steels processed by rapid heat treatment. Accordingly, samples were galvanized following designed rapid heat treatment routes. It has been shown that, the thermal cycles influenced the mechanical properties of the Dual Phase steels through the volume fraction and the distribution of martensite. In addition, the thermal treatments did not affect the formation of the inhibition layer nor the quality of the zinc coating, and this in spite of the presence of a Mn oxide layer at the steel surface during heating. [less ▲]

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See detailMicrostructure and properties of rapidly heat treated and galvanized dual phase steel
Fourmentin, Richard; Mertens, Anne ULg; McDermid, Joseph R.

in Tsuru, Tooru (Ed.) Proceedings of the 7th international conference on zinc and zinc alloy coated steel sheet (2007, November)

This study aims at determining the impact of Rapid Heat Treatment on the mechanical properties and galvanisability of a Dual Phase (DP) steel. DP steel coupons were galvanized following three rapid heat ... [more ▼]

This study aims at determining the impact of Rapid Heat Treatment on the mechanical properties and galvanisability of a Dual Phase (DP) steel. DP steel coupons were galvanized following three rapid heat treatment routes. For each thermal cycle, microstructural characteristics were related to the mechanical properties while the coating quality and reactive wetting were assessed. It was found that the thermal cycle and microsegregation of Mn in the sheet centerline influenced the mechanical properties of the Dual Phase steel through the volume fraction and distribution of non-ferritic phases, mainly martensite. In addition, the thermal treatments did not affect the reactive wetting of the Dual Phase steel nor the quality of the zinc coating, and this despite the presence of a Mn oxide layer at the steel surface during heating. Indeed, the Mn oxide layer was reduced by the Al dissolved in the zinc bath. [less ▲]

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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 ▲]

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See detailMicrostructure characterisation of nanocomposite polymeric foams by X-ray microtomography
Plougonven, Erwan ULg; Detrembleur, Christophe ULg; Tran, Minh Phuong ULg et al

Poster (2012, March 26)

Recent advances in microstructured materials have given rise to many new types of composites that exhibit original and interesting physical properties. For example, a nanocomposite made of carbon ... [more ▼]

Recent advances in microstructured materials have given rise to many new types of composites that exhibit original and interesting physical properties. For example, a nanocomposite made of carbon nanotubes inside a polymer matrix shows exceptional electromagnetic interference shielding effectiveness when foamed. However, the effective properties of such materials strongly depend on the shape and topology of the microstructural cells. An accurate method for investigating the cellular microstructure is X-ray microtomography (XRμT), for it is non-destructive, and it provides 3D geometric information. Although it cannot be used to observe nanofiller dispersion, it has a strong potential for cell structure characterisation. In order to reduce the need for trial and error in tailoring these materials, our objective is to quantify, using XRμT, cellular microstructure, for two different types of foaming procedures, namely supercritical CO2 batch foaming and freeze drying, to be able to establish a link between the structure and its shielding effectiveness. The main difficulty stems from the type of material being studied: it is light, therefore hardly absorbs X-rays, cell size is small compared to the resolution capacity of the tomograph, and cell wall thickness is extremely thin in some cases, making them very hard to discern in the images. For these reasons, common image analysis tools for identifying and delimiting objects in an image prove impractical. We propose an original method that uses the 3D autocorrelation function of the tomograms to determine statistical information from these images, such as average cell size and anisotropy, without the need to binarise and segment the images. [less ▲]

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See detailMicrostructure characterisation of nanocomposite polymeric foams by X-ray microtomography
Plougonven, Erwan ULg; Marchot, Pierre ULg; Detrembleur, Christophe ULg et al

Poster (2011, September 21)

Recent advances in microstructured materials have given rise to many new types of composites that exhibit original and interesting physical properties. For example, a nanocomposite made of carbon ... [more ▼]

Recent advances in microstructured materials have given rise to many new types of composites that exhibit original and interesting physical properties. For example, a nanocomposite made of carbon nanotubes inside a polymer matrix shows exceptional electromagnetic interference shielding effectiveness when foamed. However, the effective properties of such materials strongly depend on the shape and topology of the microstructural cells. An accurate method for investigating the cellular microstructure is X-ray microtomography (XRµT), for it is non-destructive, and it provides 3D geometric information. Although it cannot be used to observe nanofiller dispersion, it has a strong potential for cell structure characterization. In order to reduce the need for trial and error for tailoring these materials, our objective is to characterize, using XRµT, two different types of foaming procedures, namely supercritical CO2 batch foaming and freeze drying. As the resolution is limited compared to cell size, we have developed a novel statistical method based on 3D autocorrelation to determine characteristic length and examine anisotropy. We present results for these two types of foams and show the limitations of this method. [less ▲]

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See detailMicrostructure design with generalized shape optimization based on level set geometrical description and XFEM
Qiu, Kepeng; Duysinx, Pierre ULg; Zhang, Wei-Hong et al

(2009, May)

Detailed reference viewed: 100 (6 ULg)
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See detailMicrostructure development in isothermally melt-textured 123-211 composite materials
Auguste, F.; Rulmont, André ULg; Vandewalle, Nicolas ULg et al

in Journal of Low Temperature Physics (1996), 105(5-6), 1439-1444

Microstructures of isothermally melt-textured 123-211 composite materials have been examined during the solidification process from quenched specimens. The distribution of 211 particles, the ... [more ▼]

Microstructures of isothermally melt-textured 123-211 composite materials have been examined during the solidification process from quenched specimens. The distribution of 211 particles, the superconducting 123 grain boundary and the solid-liquid interface features are emphasized. The quality of the materials has been investigated by thermopower and thermal conductivity measurements. A seeded-melt texturing technique has been also tested in order to grow large single-domain of DyBa2Cu3O7-y. The chosen seed was a Dy2O3 single crystal. [less ▲]

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See detailMicrostructure of desert soil related to swelling behaviour
Marcoen, Jean Marie ULg; Tessier, D.; Zaczeck, Y.

in Ringrose-Voase, A. J.; Humphreys, G. S. (Eds.) Developments in soil Science 22, Soil Micromorphology : Studies in Management and Genesis (1994)

Detailed reference viewed: 11 (7 ULg)