References of "Lecomte-Beckers, Jacqueline"
     in
Bookmark and Share    
See detailthermal conductivity and microstructure
Lecomte-Beckers, Jacqueline ULg

Scientific conference (2005, May)

Detailed reference viewed: 5 (1 ULg)
Full Text
See detailFinit element modelling of an asynchronous motor with one broken rotor bar, comparison with the data recorded on a prototype and material aspects
Guérard, Suzanne ULg; Gyselinck, Johan; Lecomte-Beckers, Jacqueline ULg

in Bulletin Scientifique de l'AIM (Association des Ingénieurs Electriciens sortis de l'Institut Electrotechnique Montefiore) (2005), 1

This work studies the problem of broken rotor bars in cage induction motors. To this aim, an induction machine from WEG Motors was modelled by means of the finite element method. The motor modelled is a ... [more ▼]

This work studies the problem of broken rotor bars in cage induction motors. To this aim, an induction machine from WEG Motors was modelled by means of the finite element method. The motor modelled is a 18.5 kW four-pole induction motor with a straight rotor cage. The field distribution and stator phase currents were computed for a motor without broken rotor bars and for a motor with one broken rotor bar. The computed stator phase currents were compared to the ones recorded on motors respectively no broken rotor bar and with one broken rotor bar. The FE model and an equivalent scheme of the motor permitted to show that the resistance of the rotor cage was higher than expected, considering only the temperature effect on the conductivity of the rotor bars. A metallurgic analysis of the aluminium alloy of two rotor bars revealed the presence of a very high density of silicon and silicon oxide inclusions, as well as the presence of shrinkages and cracks, which have a negative impact on both conductivity and mechanical strength. A corrected value of the rotor bar conductivity was used in the finite element model and led to a good agreement with the experimental results. The field perturbation associated with a broken rotor bar produces a concentration of flux near the bar ahead of the broken one, considering the counterclockwise direction of rotation of the rotor. This flux concentration results in higher current values and hence in higher stresses in the bar ahead of the broken one. [less ▲]

Detailed reference viewed: 112 (6 ULg)
Full Text
Peer Reviewed
See detailDetermination of the optimal forging conditions of a Cr-Mo-V high alloy steel through a microstructural, thermophysical and mechanical study
Bouffioux, Chantal ULg; Carton, Marc ULg; Lecomte-Beckers, Jacqueline ULg et al

in Banabic, D. (Ed.) Proceedings of the 8th ESAFORM Conference on Material Forming (Vol. 1) (2005)

The forging process of cylinders requires the knowledge of material recrystallisation conditions to prevent crack appearance. Due to the continuous recrystallisation during forging, very large ... [more ▼]

The forging process of cylinders requires the knowledge of material recrystallisation conditions to prevent crack appearance. Due to the continuous recrystallisation during forging, very large deformations can be applied as the generated dislocations do not yield to hardening but to recrystallisation phenomenon. This paper summarizes the data identification of a FEM recrystallisation model and defines the optimal forging process for one roll. [less ▲]

Detailed reference viewed: 76 (7 ULg)
Full Text
Peer Reviewed
See detailStudy of liquid fraction evolution of semi-solid steels for thixoforming
Lecomte-Beckers, Jacqueline ULg; Rassili, Ahmed ULg; Carton, Marc ULg et al

in Proceedings of the 8th ESAFORM Conference on Material Forming (2005)

Major challenge for semi-solid processing includes broadening the range of alloys that can be successfully thixoformed and developing alloys specifically for thixoforming. One important parameter is ... [more ▼]

Major challenge for semi-solid processing includes broadening the range of alloys that can be successfully thixoformed and developing alloys specifically for thixoforming. One important parameter is appropriate solidus-liquidus interval. The wider the solidification interval, the wider the processing window. This study is related to the experimental determination of this critical parameter on eight different steel compositions. This parameter was obtained using Differential Scanning Calorimetry. This technique allows to obtain the solid fraction versus temperature. [less ▲]

Detailed reference viewed: 21 (0 ULg)
Full Text
See detailUse of Microscopy for identification of complex MC, M2C, M6C, M7C3 and M23C6 carbides in high speed-steels
Lecomte-Beckers, Jacqueline ULg; Tchuindjang, Jérôme Tchoufack ULg

in GIT - Imaging and Microscopy (2005), 2

High-speed steels (HSSJ rofis are useci in front finishing stands of hot strip mils. Good wear resistance and hardness at high temperature are defining features of HSS. Many types of carbides are present ... [more ▼]

High-speed steels (HSSJ rofis are useci in front finishing stands of hot strip mils. Good wear resistance and hardness at high temperature are defining features of HSS. Many types of carbides are present in these alloys, each having different effect upon the final properties of HSS. As a resuit, nature, morphology and amount of these carbides are factors of important concern. Identification and characterisation of HSS carbides are realised with optical microscopy comhined with electron microscopy. [less ▲]

Detailed reference viewed: 78 (12 ULg)
Full Text
See detailStudy of the liquid fraction and thermophysical properties of semi-solid steels and application to the simulation of inductive heating for thixoforming
Lecomte-Beckers, Jacqueline ULg; Rassili, Ahmed ULg; Carton, Marc ULg et al

in Bananic, Dorel (Ed.) Advanced Methods in Material Forming (2005)

The thixoforming of steels is so complex that it requires more investigations regarding both the materials and the technical tools dedicated to the elaboration of the process. In this paper we will show ... [more ▼]

The thixoforming of steels is so complex that it requires more investigations regarding both the materials and the technical tools dedicated to the elaboration of the process. In this paper we will show the experimental determination of appropriate solidus-liquidus interval on eight different steel compositions. This critical parameter was obtained using Differential Scanning Calorimetry. The paper also presents the results of thermophysical property determination. These parameters are important for the inductive heating phase of a semi-solid forming (SSF) process. Thanks to the simulations of the inductive heating process, the other main results consist on the developments of the heating techniques that are suitable for the achieving of the sine qua none condition to the semi-solid process, which is the uniform temperature distribution in the reheated billet. [less ▲]

Detailed reference viewed: 78 (11 ULg)
See detailTitanium alloys
Lecomte-Beckers, Jacqueline ULg

Scientific conference (2004, June)

Detailed reference viewed: 7 (1 ULg)
Full Text
Peer Reviewed
See detailMesoscopic model of intergranular cracks in low carbon steel during cooling of continuous casting
Castagne, S.; Pascon, Frédéric ULg; Lecomte-Beckers, Jacqueline ULg et al

in Lamberigts, M. (Ed.) Proceedings of the 2nd international conference of thermomechanical processing of steels (TMP 2004) (2004)

This paper addresses the problem of transverse cracking during the continuous casting of low carbon steel. The damage mechanisms occurring at high temperature during this process are identified and a ... [more ▼]

This paper addresses the problem of transverse cracking during the continuous casting of low carbon steel. The damage mechanisms occurring at high temperature during this process are identified and a numerical approach for the modelling of these phenomena at the grain scale is proposed. Experiments allowing the identification of the model’s parameters are described. Finally, the first results obtained with the model are presented. [less ▲]

Detailed reference viewed: 51 (5 ULg)
Full Text
Peer Reviewed
See detailMelting and crystallisation behaviour of multi-component Fe-C-Cr-X alloys : microstructural aspects
Tchuindjang, Jérôme Tchoufack ULg; Lecomte-Beckers, Jacqueline ULg

in Proceedings of the 13th European Microscopy Congress (2004)

Studied materials are of the Fe-C-Cr-X multi-component system where X represents a group of strong carbides formers as Mo, V, or Nb. These alloys are used for wear components. Differential Thermal ... [more ▼]

Studied materials are of the Fe-C-Cr-X multi-component system where X represents a group of strong carbides formers as Mo, V, or Nb. These alloys are used for wear components. Differential Thermal Analysis (DTA) was used to determine the melting and solidification behaviour of these materials. Raw material has a thermomecanical history that involved casting, heat treating and hot forming, which could be investigated by the melting sequence of the DTA trial. [less ▲]

Detailed reference viewed: 23 (6 ULg)