References of "Tchuindjang, Jérôme Tchoufack"
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See detailComparison of the wear behavior of high speed steel grades obtained from conventional casting and laser cladding
Hashemi, Seyedeh Neda ULg; Dedry, Olivier ULg; Lecomte-Beckers, Jacqueline ULg et al

in Materiaux et tribologie jift 2014 (2015)

The wear characteristics of three high speed steel grades were studied, one of them being obtained from a conventional casting process and two others originated from a laser cladding route. Tribological ... [more ▼]

The wear characteristics of three high speed steel grades were studied, one of them being obtained from a conventional casting process and two others originated from a laser cladding route. Tribological tests were carried out at room temperature using a “pin-on-disc” device. The setting of the wear test parameters together with the microstructure of the studied materials seems to strongly influence the subsequent abrasion and wear mechanisms. The results show that the laser cladded high speed steel materials resist better to wear thanks to their ultrafine microstructure compared to the conventional cast material. [less ▲]

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See detailRAPPORT SCIENTIFIQUE & TECHNIQUE FINAL - Projet BLUM – RW 6800
Lecomte-Beckers, Jacqueline ULg; Tchuindjang, Jérôme Tchoufack ULg; Paydas, Hakan ULg

Report (2015)

Le projet BluM® s’inscrit dans la continuité du projet Blisk. En effet les trade-off architecturaux du projet Blisk plan Marshall ont conduit Techspace Aero à se tourner vers le développement d’un concept ... [more ▼]

Le projet BluM® s’inscrit dans la continuité du projet Blisk. En effet les trade-off architecturaux du projet Blisk plan Marshall ont conduit Techspace Aero à se tourner vers le développement d’un concept encore plus porteur en terme de masse et plus ambitieux en terme de défi technologique que les blisk « classiques ». Il s’agit du développement de composant rotorique multi étage monobloc, d’où l’acronyme BluM® pour Bladed Drum. Sur les turboréacteurs actuels, les compresseurs basse pression comportent un tambour, dont le fût se compose de glissières circulaires dans lesquelles on introduit les aubes. Le projet apporte des solutions nouvelles à la conception du compresseur basse pression. Avec le BluM®, le principe du tambour est conservé sur lequel les aubes seront soudés par friction, une technique qui commence à se développer dans le domaine de la propulsion aéronautique. Elle offre un soudage à la fois précis et très résistant car les propriétés mécaniques du titane sont conservées. En intégrant l’aube au tambour, on supprime l’encoche et le pied d’aube et l’on réalise ainsi des gains de masse importants. Le concept BluM® permet d’envisager une réduction de masse de 20% sur l’ensemble rotorique. En outre le projet vise à mener une série d’études, d’évaluation et de modélisations très avancées de l’impact du concept sur la performance aéromécanique. L’objectif du projet est de développer cette technologie pour lui permettre d’atteindre un niveau de maturité suffisant pour être éligible sur un programme de développement à partir de 2014. Pour atteindre ce niveau de maturité les activités comprendront le développement de nouvelles méthodologies de dimensionnement et de modélisation, des essais partiels (matériaux, procédés, banc partiel) et la conception et la production d’un prototype pour validation en essai moteur. [less ▲]

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See detailCharacterization of the Solidification Path, the Solid State Transformations and the Mechanical Behavior of a High Chromium Cast Steel
Tchuindjang, Jérôme Tchoufack ULg; Neira Torres, Ingrid; Habraken, Anne ULg et al

in Proceedings of the 5th Abrasion Conference - 2014 (2014, August)

The mechanical behavior of the fully austenitic matrix of a High Chromium Cast Steel (HCCS) alloy has been determined under external compression stress applied at 300°C and 700°C. The solidification path ... [more ▼]

The mechanical behavior of the fully austenitic matrix of a High Chromium Cast Steel (HCCS) alloy has been determined under external compression stress applied at 300°C and 700°C. The solidification path and the microstructure have been studied, including the nature and the critical temperature ranges for carbides formation, while using Differential Thermal Analysis and both Optical and Scanning Electron Microscopes. The microstructure has been characterized towards both Optical and SEM analyses. Differential Thermal Analysis and Dilatometry were used to study the solid state phase transformations on the one hand, and precipitation and dissolution reactions on the other hand, especially during heating from room temperature up to austenitization, and subsequent cooling down to room temperature. Dilatometry also helps setting the parameters for the preliminary thermal treatments to perform prior to compression tests, in order to allow more or less transition carbides within the stressed microstructure, the other carbides remaining undissolved. Flow stress curves and related work hardening rates were determined for both temperatures. From the compression tests, various strengthening phenomena, such as precipitation hardening and stress induced bainite transformation, and one softening mechanism such as recovery, have been highlighted, while enhancing at the same time the influence of the temperature and the carbide type on the mechanical behavior of the HCCS material. Cracks observed on grain boundaries primary carbides allow establishing a rough damage model. The crack initiation within the HCCS alloy seems to be strongly dependent on the temperature, the external applied stress and the matrix toughness. [less ▲]

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See detailStudy of residual stresses in bimetallic work rolls
Neira Torres, Ingrid ULg; Gilles, Gaëtan ULg; Tchuindjang, Jérôme Tchoufack ULg et al

in Advanced Materials Research (2014), 996

An experimental campaign of compression tests, differential thermal analysis (DTA), differential scanning calorimetry ( DSC), dilatometry and microstructure analysis has been performed, as well as the ... [more ▼]

An experimental campaign of compression tests, differential thermal analysis (DTA), differential scanning calorimetry ( DSC), dilatometry and microstructure analysis has been performed, as well as the identification of the material data set for finite element ( FE) analysis of bimetallic rolls. This article numerically investigates the stress and strain fields after the cooling stage and it checks their effect on the subsequent heat treatment step. As bimetallic rolls have a different material for core and shell, the effect of the roll size and the shell thickness on residual stresses is also studied. [less ▲]

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See detailRapport Final, PROJET RECYLCLAD RW 11-1-7335 : Fabrication de Cylindres Bimétalliques par Rechargement Laser (Laser Cladding) d’Aciers à Outils optimisés sur Axes Réutilisables
Lecomte-Beckers, Jacqueline ULg; Tchuindjang, Jérôme Tchoufack ULg; Dedry, Olivier ULg et al

Report (2013)

Le présent rapport contient les résultats principaux des analyses réalisées au sein du laboratoire MMS (Métallurgie et Science des Matériaux) de l’Université de Liège, durant les deux premières années de ... [more ▼]

Le présent rapport contient les résultats principaux des analyses réalisées au sein du laboratoire MMS (Métallurgie et Science des Matériaux) de l’Université de Liège, durant les deux premières années de la recherche, à savoir la période allant du 01/12/2011 au 30/11/2013. Le service MMS est à la fois partenaire et coordinateur du projet RECYLCLAD. [less ▲]

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See detailStudy of phase transformations within bimetallic rolling mills
Neira Torres, Ingrid ULg; Lecomte-Beckers, Jacqueline ULg; Tchuindjang, Jérôme Tchoufack ULg et al

Scientific conference (2013, September 10)

With the aim of simulating the cooling behavior after a re-austenitizing stage of bimetallic rolling mills, both materials corresponding to spheroidal graphite iron (core material) and high chrome steel ... [more ▼]

With the aim of simulating the cooling behavior after a re-austenitizing stage of bimetallic rolling mills, both materials corresponding to spheroidal graphite iron (core material) and high chrome steel (shell material) must be characterized through thermo physical and mechanical tests as well as microscopic observations. Dilatometer tests were carried out for both materials in order to determinate thermo physical properties such as thermal expansion coefficient and density. Compression tests were also performed in order to estimate the effect of mechanical stress on martensite phase transformation, especially the nature and the type of martensite and start of transformation temperature. However there are some parameters that are still unknown and that are highly difficult to determinate. Inverse simulations are performed through Lagamine code with the aim of finding an estimated value for these parameters or improved parameters, more accurate than the ones already estimated. [less ▲]

Detailed reference viewed: 159 (43 ULg)