Determination of Material Properties in the Semi-Solid State Using Gleeble Simulator

2007 ◽  
Author(s):  
Krzysztof Sołek ◽  
Roman Kuziak ◽  
Plato Kapranos
2019 ◽  
Vol 285 ◽  
pp. 361-366 ◽  
Author(s):  
Khalil Traidi ◽  
Véronique Favier ◽  
Philippe Lestriez ◽  
Karl Debray ◽  
Laurent Langlois ◽  
...  

In this paper, a new elastic viscoplastic micromechanical modelling is proposed to represent the semi-solid behaviour and predict the ductile-brittle transition of the C38LTT near the solidus. It is based on a viscoplastic modelling previously presented in [1]. The originality of the new model comes from three main enhancements: the transition between the solid state and the semi-solid state was included meaning that the material properties were taken temperature-dependent, the elastic properties was taken into account similarly as [2] and the evolution of the internal variable describing the degree of agglomeration of the solid phase was enhanced. The model was implemented in the commercial software FORGE©. Tensile tests representing the experimental thermal conditions and obtained using a GLEEBLE© machine were simulated. The comparison of the predicted and experimental results shows that, for the first time to our knowledge, the three steps of the load-displacement response and ductile-brittle transition were successfully described.


2017 ◽  
Vol 107 (05) ◽  
pp. 340-345
Author(s):  
J. Uphoff ◽  
A. Lechler ◽  
A. Prof. Verl

Das Thixoforming nutzt bei der Formgebung besondere Materialeigenschaften zur Herstellung metallischer Bauteile. Die verwendeten Legierungen müssen dazu in den sogenannten teilflüssigen Bereich erwärmt werden. Das Einstellen des geforderten Fest-Flüssig-Verhältnisses stellt besondere Anforderungen an die Erwärmung. Betrachtet werden verschiedene Messverfahren, welche die Induktorspule bei der induktiven Erwärmung als Sensor nutzen.   Thixoforming uses specific material properties for shaping metal workpieces. For this purpose, the alloys need to be heated to the so-called semi-solid state. The adjustment of the desired semi-solid fraction imposes high requirements on the heating process. Various measurement principles, which use the inductor-coil as a sensor in inductive heating processes, are presented.


2003 ◽  
Vol 791 ◽  
Author(s):  
Vladimir P. Oleshko ◽  
James M. Howe

ABSTRACTQuantized high-frequency (∼1016 Hz) correlated longitudinal electron excitations (plasmons) generated in the energy-loss range 0–50 eV by fast electrons passing through any solid enable one to probe various states of matter. Their energy, Ep, is directly related to the density of valence electrons, thus allowing determination of solid-state properties that are governed by ground-state densities. Universal features and scaling in relations between Ep and the cohesive energy per atomic volume, bonding electron density and elastic constants have been established. The resulting correlations follow the universal binding energy relationship, thus providing new insights into the fundamental nature of structure-property relationships. They allow direct in situ determination of local material properties in an analytical electron microscope, as illustrated by examples utilizing Al- and Ti-based structural alloys.


2012 ◽  
Vol 192-193 ◽  
pp. 191-196
Author(s):  
Guo Chao Gu ◽  
Raphaël Pesci ◽  
Eric Becker ◽  
Laurent Langlois ◽  
Régis Bigot

The distribution of liquid at the semi solid state is one of the most important parameters for steel thixoforging. It has a great influence on the viscosity of the material, on the flows and finally on the final shape and mechanical properties of the thixoforged parts. Both ex situ and in situ 3D X-ray microtomography characterizations have been carried out to determine the quantity and localization of liquid at high temperature of M2 steel slugs. Microtomography was first performed ex situ at room temperature on samples heated and quenched from semi-solid state. The specimens were also scanned in situ directly at high temperature. The obtained results have been compared to 2D observations using EDS technique in SEM on heated and quenched specimens. They showed a good correlation making both approaches very efficient for the study of the liquid zones at the semi-solid state


2020 ◽  
Vol 835 ◽  
pp. 229-242
Author(s):  
Oboso P. Bernard ◽  
Nagih M. Shaalan ◽  
Mohab Hossam ◽  
Mohsen A. Hassan

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.


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