References of "Lecomte-Beckers, Jacqueline"
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See detailComportement des matériaux métalliques utilisés dans les systèmes énergétiques
Lecomte-Beckers, Jacqueline ULg

Learning material (1996)

Matériaux métalliques - mécanismes de déformation, modes de durcissement. Liaison entre microstructure et propriétés, schématisation des comportements réels. - Matériaux pour turbine à vapeur (aciers ... [more ▼]

Matériaux métalliques - mécanismes de déformation, modes de durcissement. Liaison entre microstructure et propriétés, schématisation des comportements réels. - Matériaux pour turbine à vapeur (aciers faiblement alliés - aciers 9-12% Cr - aciers fortement alliés). - Matériaux pour systèmes énergétique avancé (alliages ODS). Matériaux pour turbines à gaz (superalliages - intermétalliques - Titane - solidification dirigée - monocristal). - Evaluation des défauts en service. - Prédiction de la durée de vie. - Corrosion et revêtements (TBC). - Endommagement : rupture brutale, fluage et fatigue, corrosion sous tension. - Visite d'une installation. [less ▲]

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See detailProtection contre la corrosion
Lecomte-Beckers, Jacqueline ULg

Learning material (1996)

Aspect phénoménologique des attaques de corrosion. - Thermodynamique des réactions de corrosion. - Surfaces et interfaces. - Vitesse des réactions de corrosion. - Passivité des métaux. - Mécanismes de ... [more ▼]

Aspect phénoménologique des attaques de corrosion. - Thermodynamique des réactions de corrosion. - Surfaces et interfaces. - Vitesse des réactions de corrosion. - Passivité des métaux. - Mécanismes de corrosion (piles - piqûres - corrosion galvanique). - Oxydation et corrosion atmosphérique. - Corrosion à haute température. - Corrosion-érosion - Corrosion microbiologique. - Fissuration sous contrainte. - Protection contre la corrosion; critères de choix. - Importance de la corrosion dans l'industrie - cas particuliers. [less ▲]

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See detailCorrosion des Matériaux métalliques
Lecomte-Beckers, Jacqueline ULg

Learning material (1995)

Aspect phénoménologique des attaques de corrosion. - Thermodynamique des réactions de corrosion. - Surfaces et interfaces. - Vitesse des réactions de corrosion. - Passivité des métaux. - Mécanismes de ... [more ▼]

Aspect phénoménologique des attaques de corrosion. - Thermodynamique des réactions de corrosion. - Surfaces et interfaces. - Vitesse des réactions de corrosion. - Passivité des métaux. - Mécanismes de corrosion (piles - piqûres - corrosion galvanique). - Oxydation et corrosion atmosphérique. - Corrosion à haute température. - Corrosion-érosion - Corrosion microbiologique. - Fissuration sous contrainte. - Protection contre la corrosion; critères de choix. - Importance de la corrosion dans l'industrie - cas particuliers. [less ▲]

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See detailInfluence of creep on the microstructure of Zn-Al-Cu alloys aged at 250°C
Terziev, L.; Lecomte-Beckers, Jacqueline ULg; Wegria, J.

in Physica Status Solidi A : Applied Research (1995), 152[2]

This paper is a continuation of a microstructural study of ZA alloys subjected to ageing at different temperatures with subsequent creep at 20 and 120 °C. it was already established that the samples aged ... [more ▼]

This paper is a continuation of a microstructural study of ZA alloys subjected to ageing at different temperatures with subsequent creep at 20 and 120 °C. it was already established that the samples aged for one week at 100 and 250 °C show the slowest creep rate. Furthermore, the resuits obtained afler ageing at 250 °C are better than those obtained after ageing at 100 °C. In order to explain more correctly these resuits, the microstructure is studied after ageing at 250 oc and subsequent creep at room temperature under pressure at 100 MPa and at 120 °c under pressure at 40 MPa, on test samples broken after the respective creep. [less ▲]

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See detailEffect of microstructural transformation on the creep resistance of Zn-Al-Cu alloys
Lecomte-Beckers, Jacqueline ULg; Terziev, Luben

in Proceedings of Trinocular Joint Meeting on Electron Microscopy (1995)

This paper illustrates the modification of the structure induced by creep treatments. The aim of this study is to compare the evolution of the structure after creep tests on samples treated at 100°C and ... [more ▼]

This paper illustrates the modification of the structure induced by creep treatments. The aim of this study is to compare the evolution of the structure after creep tests on samples treated at 100°C and 250°C. Creep tests have been carried out at 120°C with a tensile stress of 40 MPa and at 20°C with a tensile stress of 100 MPa. [less ▲]

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See detailMicrostructural study of a zinc-aluminium-copper alloy after thermal treatment at 100°C and creep
Terziev, L.; Lecomte-Beckers, Jacqueline ULg; Wegria, J.

in Zeitschrift für Metallkunde (1994), 85[9]

The creep behaviour of the ternary Zn—A1—Cu alloy after thermal treatment at ioo oc has been studied. The applied creep stress does flot modify clearly the transition phases (OL, T% ‘11m) appearing during ... [more ▼]

The creep behaviour of the ternary Zn—A1—Cu alloy after thermal treatment at ioo oc has been studied. The applied creep stress does flot modify clearly the transition phases (OL, T% ‘11m) appearing during isothermal ageing. During the creep test, the formation of an important density of defects resuits in the precipitation of T’ and O’ particles. The quantity of these phases depends on the creep conditions. [less ▲]

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See detailEtude des relations entre les microstructures obtenues par vieillissement isotherme et le comportement mécanique (fatigue, résilience) dans des alliages Zn-Al et Zn-Al-Cu
Lecomte-Beckers, Jacqueline ULg; Terziev, L.; Wegria, J.

in Revue de Métallurgie [=Revue de Métallurgie. Cahiers d'Informations Techniques] (1994), 91[5]

L’article présenté établit une corrélation entre le comportement mécanique (fluage, résilience) et les microstructures qui apparaissent au cours d’un traitement thermique isotherme (100 ou 250 °C) dans ... [more ▼]

L’article présenté établit une corrélation entre le comportement mécanique (fluage, résilience) et les microstructures qui apparaissent au cours d’un traitement thermique isotherme (100 ou 250 °C) dans des alliages Zn-Al et Zn-Al-Cu1. Le but est de mettre en évidence l’intérêt pratique des modifications structurales obtenues. On observe un meilleur résultat pour des échantillons vieillis pendant une semaine environ. La température de traitement la plus favorable est 250 °C. De plus, les alliages contenant du cuivre possèdent un meilleur comportement que les alliages binaires Zn-Al. [less ▲]

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See detailEffect of isothermal ageing on the Zn-Al alloys creep characteristics
Lecomte-Beckers, Jacqueline ULg; Terziev; Wegria et al

in Proceedings of The 3rd International Conference on Zn-Al Alloys - Advances in Science, Technology and Applications of Zn-Al Alloys (1994)

The aim of this study is to correlate the creep parameters of aged Zn-Al samples with the microstructure developed during heat treatment, and to point out the practical interest of such microstructure ... [more ▼]

The aim of this study is to correlate the creep parameters of aged Zn-Al samples with the microstructure developed during heat treatment, and to point out the practical interest of such microstructure modifications. Two different isothermal ageings were carried out at 100°C and at 250°C for different periods of times (from 30 min. to 8 weeks). During those ageings, complex precipitations occur. The decomposition of the initial supersaturated solid solution begins with a cellular reaction leading to cfc and hcp lamellar. The cfc phase decomposes into transition phases. The ageing temperature (100 or 250°C) influences the decomposition stages. Creep testson aged samples reveal the influence of the microstructure developed during the heat treatment at 100 or 250°C. An improvement of the creep properties by one order of magnitude can be observed when the sample exhibits the appropriate structure. [less ▲]

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See detailMechanical properties and recrystallisation behaviour of Fe base ODS alloys
Lecomte-Beckers, Jacqueline ULg; Coutsouradis, D.; Lecomte-Mertens, Ch. et al

in Proceedings of PM'94, Congrès mondial de Métallurgie des Poudres (1994)

Developments in higher temperature exchangers and other applications require high strength as well as oxidation resistance at very high temperature. In order to meet such requirements, Dour Metal has ... [more ▼]

Developments in higher temperature exchangers and other applications require high strength as well as oxidation resistance at very high temperature. In order to meet such requirements, Dour Metal has developed ODM new range of oxide dispersion strengthened (ODS) iron base alloys realised by powder mechanical alloying. Compositional and thermomechanical manipulations can be used to develop the structure enabling the service temperature to be increased up to about 1200°C. An optimization of the structure is required to obtain the best high temperature creep resistance. This consist in minimizing the grain densities and the misorientation between adjoining grains. The paper will discuss some results on evolution of the texture during different thermomechanical treatments on ODS Fe base tubes. Typical rupture strength will be presented for temperature ranging from 900 to 1100°C. The emphasis will be given to alloy ODM 751 which most recent work has been performed. [less ▲]

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See detailRecrystallisation behaviour of Fe base ODS alloys
Lecomte-Beckers, Jacqueline ULg; Coutsouradis, D.; Kazimierzak, B.

in Proceedings of the International Conference on Materials for Advanced Power Engineering (1994)

Developments in higher temperature exchangers and other applications require high strength as well as oxidation resistance. In order to meet such requirements, Dour Metal has developed the 0DM new range ... [more ▼]

Developments in higher temperature exchangers and other applications require high strength as well as oxidation resistance. In order to meet such requirements, Dour Metal has developed the 0DM new range of oxide dispersion strengthened (ODS) iron based alloy. Compositional and thermomechanical manipulations can be used to develop the structure enabling (be service temperature to be increased up W about 1200°C. In both Ni and Fe base ODS materials, an optimization of the structure is required to obtain the best high temperature creep resistance. This consists in minimizing the grain boundaries density and misorientation between adjoining grains. ODS Fe base alloys and Ni base alloys differ as follows: - for alloys with high stacking fault energy (as ferritic steel) the phenomenon involved during hot deformation is dynamic recovery - for alloys with low stacking energy (as Ni alloys and austenilic steels) the phenomenon is dynamic recrystallization. The texture obtained during recovery is weIl marked and leads to 10w angle boundaries. A static treatment in bot furnace is then enough to develop the secondary dynamic recrystallization. Dynamic recrystallization leads to randomly oriented grains with high angle boundaries. A secondary dynamic recrystallization is then more difficult and oriented recrystallization leading to an oriented texture must be favoured by creating a thermal gradient during the treatment. The paper discusses some results on (lie evolution of the texture during treatments on ODS Fe base alloy tubes. It is pointed out that to obtain the temperature, it is important to control the thermomechanical treatments from recrystallization treatment. [less ▲]

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See detailEvolution of microstructure during creep of thermally treated Zn-Al-Cu alloy
Lecomte-Beckers, Jacqueline ULg; Terziev, L.; Wegria, J.

in Proceedings of the 13th International Congress on Electron Microscopy (1994)

This paper illustrates the modifications of the structure induced by creep treatments. The aim of this study is to compare the evolution of the structure after creep tests on samples treated at 100°C and ... [more ▼]

This paper illustrates the modifications of the structure induced by creep treatments. The aim of this study is to compare the evolution of the structure after creep tests on samples treated at 100°C and 250°C. Creep tests have been carried out at 120°C with a tensile stress of 40MPa and at 20°C with a tensile stress of 100MPa. [less ▲]

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See detailMatériaux métalliques spéciaux
Lecomte-Beckers, Jacqueline ULg

Learning material (1993)

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See detailTEM investigation of transition phases precipitation in ZA alloys after isothermal aging at 250°C and subsequent creep at high temperature
Lecomte-Beckers, Jacqueline ULg; Terziev, L.; Wegria, J.

in Materials Science Forum (Intergranular and Interphase Boundaries in Materials) (1993), 126-128

Transition phases occurring during isothermal aging at 250°C af ternary Zri-A1-Cu alloys are modlifîed after creep at high temperature. fle pressure applkd during creep leads to a high dertsity of clef ... [more ▼]

Transition phases occurring during isothermal aging at 250°C af ternary Zri-A1-Cu alloys are modlifîed after creep at high temperature. fle pressure applkd during creep leads to a high dertsity of clef ects which modifies the ndcrostructure. 11e trnsitiôn phases are studied by me ans of transmission electron microscopy and diffraction technique. Œ’r and phases pile up on dislocations. 11e reaction «s + £ 4 T +r 1$ accelerated and the transition T’ -. e’ is proxnoted by the defects. [less ▲]

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See detailRole of impurities in reclaimed WC-TaC-TiC-Co powders used in cutting tools.
Magnée, Adrien ULg; Lecomte-Beckers, Jacqueline ULg

in Proceedings of the International Conference on Advances in Hard Materials Production (1992)

The purpose of the present work was to examine the effect of recycling and the effect of intentional impurities (CaS, Al2O3, Zn, SiO2) on some properties (transverse rupture strength, hardness and cutting ... [more ▼]

The purpose of the present work was to examine the effect of recycling and the effect of intentional impurities (CaS, Al2O3, Zn, SiO2) on some properties (transverse rupture strength, hardness and cutting tests) of WC-TaC-TiC-Co. In all cases the batches of powders were processed under identical conditions with sintering carried out in laboratory. Damage study of the sintered carbides plates during cutting tests have been interpretated following the Taylor's law, relating the tool lifes as a function of cutting speed. [less ▲]

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See detailElectron microscopical investigations of hexagonal phase precipitation in Zn---12 wt% Al---1 wt% Cu and Zn---27 wt% Al---2 wt% Cu alloys
Rachev, P.; Terziev, L.; Lecomte-Beckers, Jacqueline ULg et al

in Acta Metallurgica et Materialia (1991), 39(9), 2177-2182

In Zn---12 wt% Al---1 wt% Cu and Zn---27 wt% Al---2 wt%Cu alloys aged at 100° and 250°C the precipitation of h.c.p. phases was studied by means of transmission electron microscopy. The presence of the ... [more ▼]

In Zn---12 wt% Al---1 wt% Cu and Zn---27 wt% Al---2 wt%Cu alloys aged at 100° and 250°C the precipitation of h.c.p. phases was studied by means of transmission electron microscopy. The presence of the metastable ηm and ηx-phases was established using the Moiré pattern method. The ηm → η phase transition was observed. Screw dislocations are visualized in (114) with b logical and {220} in η phase precipitates by means of Moiré fringes. [less ▲]

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See detailStudy of composite aluminium alloys produced by stir casting
Lecomte-Beckers, Jacqueline ULg; Coutsouradis, D.; Lamberigts, M.

in Proceedings of the International Conference on Advanced Aluminium and Magnesium Alloys (1990)

Solidification processing of aluminium alloys reinforced by short fibers and particles of SIC was studied. The reinforcements were introduced and dispersed into aluminium alloys melts by the vortex method ... [more ▼]

Solidification processing of aluminium alloys reinforced by short fibers and particles of SIC was studied. The reinforcements were introduced and dispersed into aluminium alloys melts by the vortex method. The paper describes the fabrication process used to provide adequate bonding between reinforcemments and liquid matrix. The commercial alloys (2024, 319) containing element such as Cu or Mg chosen to provide adequate wetting were used and compared. The samples were used in the as-cast state or after hot rolling. The samples were examined both in the as-cast or as-rolled and heat treated conditions (T6). The specimens were submitted to microstructural examinations (optical and SEM) density measurements and mechanical property evaluation. Examinations of the results by statistical analyses show that both SIM chopped fibers and particles increase significantly the mechanical properties of the alloys especially at high temperature. However it is shown that the behaviour of the different alloys is strongly different. The effect reinforcement depends on the nature of the alloy and can be related to microstructural features. [less ▲]

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See detailPhase formation during aging of Zn-12% Al and Zn-27% Al alloys at 100°C.
Terziev, L.; Rachev, P.; Lecomte-Beckers, Jacqueline ULg et al

in Zeitschrift für Metallkunde (1990), 81[6]

The phase formation during ageing of ZrH2 wt% AI and Zna27 wt.% AI alloys at 100 O has been studied by means of transmission electron microscopy and electron diffraction. No formation of ellipsoidal ... [more ▼]

The phase formation during ageing of ZrH2 wt% AI and Zna27 wt.% AI alloys at 100 O has been studied by means of transmission electron microscopy and electron diffraction. No formation of ellipsoidal precipitates of GP 2 and c4 phase bas been observed. Precipitation of hexagonal phases occurs generally on account of the a phase. The <011> habitus plane of a new phase q has been found. The q phase has been distinguished from the metastable Qm using Moire patterns [less ▲]

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See detailSilicon carbide fibers and particles reinforced aluminium alloys produced by stir casting
Lecomte-Beckers, Jacqueline ULg; Coutsouradis, D.; Lamberigts, M.

in Proceedings of The 4th European Conference on Composite Materials - Developments in The Science and Technology of Composite Materials (1990)

This study is concerned with the solidification processing of aluminium alloys reinforced by short fibers and particles of SiC. The reinforcements have been introduced and dispersed into aluminium alloys ... [more ▼]

This study is concerned with the solidification processing of aluminium alloys reinforced by short fibers and particles of SiC. The reinforcements have been introduced and dispersed into aluminium alloys melts by the vortex method. The commercial alloys (2024, 319) containing elements such as Cu or Mg chosen to provide adequate wetting have been used and compared. The samples have been examined both in the as-cast or as-rolled and heat treated conditions (T6). Examinations of the mechanical properties by statistical analyses show that both SiC chopped fibers and particles increase significantly the mechanical properties of the alloys especially at high temperature. [less ▲]

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