Becker, Eric (2008) Experimental and numerical investigations for the key parameters identification of the steel thixoforging of a part. PhD thesis Mécanique et Matériaux, Laboratoire de Génie industriel et P¨roduction Mécanique équipe IFab, ENSAM 2008ENAM0038 p.300.
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Abstract
Industry is permanently looking for minimizing production time and cost, simplifying their manufacturing process while maximizing the quality of their products. This is applied by the metal forming industry. In this context, an innovative forming process, the thixoforging, is developed, making it possible to manufacture complex parts with elevated mechanical properties. Moreover the thixoforging permit to minimize the number of phases of the manufacturing process.This process uses the semi-solid state properties of metal alloys, this state being obtained by partial fusion of the solid. For steel thixoforging, the difficulties related to the work temperature and the lack of knowledge of the mechanical and thermomechanical behavior of the material. These make the industrial process development difficult. This thesis contributes to improve comprehension of the steel behaviour during thixoforging. The objective is also to develop the exploitation of the original multi-scale model “micro-macro”, and its implementation in the 2D and 3D Forge2007®.software. To achieve this goal, experimental testing with a specific and innovative device was carried out. The main thixoforging parameters were identified and studied. These parameters are the forming speed, the initial steel temperature and the initial tool temperature. For each test, the evolution of the forming load, the nature of the plastic flow and the quality of the thixoforged parts characterised by the macrographic and micrographic observations of their metallurgical structure and mechanical tests, were studied. Tests with instrumented tools also allowed a characterization of heat exchange between the tool and the part during forming. This big number of tests made it possible to describe the influence and to show the importance of the forming speed, the initial temperature of the steel and the initial temperature of the tool during thixoforging of a part.These tests were also used as a basis for calibration of the “micro-macro” model multi-scale and the heat exchange coefficients between the tool and the part. The tests and simulations were compared in order to determine and improve the predictive model capacity implemented in Forge2007® software.
| Item Type: | PhD Thesis (PhD) |
|---|---|
| PhD Supervisor: | Bigot, Régis |
| Date: | 02 December 2008 |
| Board of examiners: | Chastel, Yvan and Dubar, Laurent and Lafon, Pascal and Hirt, Gerhard and Favier, Véronique and Bigot, Régis and Langlois, Laurent and Cézard, Pierre |
| Ecole Doctorale: | ED 432 ECOLE DOCTORALE SCIENCES DES METIERS DE L'INGENIEUR |
| Discipline: | Mécanique et Matériaux |
| Collection (Fonds): | Arts et Métiers ParisTech (ENSAM) |
| Institution: | ENSAM |
| Department: | Laboratoire de Génie industriel et P¨roduction Mécanique équipe IFab |
| Subjects: | 4. Materials Science, Mechanics and Mechanical Engineering |
| Uncontrolled Keywords: | Thixoforging, Steel, Semi-solid, Forming conditions, Material flow, Macrographies, Micrographies, Micro-macro model, Tool, Part heat exchange, Thixoforgeage, Acier, Semi-solide, Conditions de mise en forme, écoulement, Macrographies, Micrographies, Modèle micro-macro, échange thermique outil, Pièce |
| ID Code: | 4477 |
| Deposited By: | Eric BECKER |
| Deposited On: | 23 June 2009 |
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