Experimental and Simulation Study of Microstructure of the Aluminium Alloy 319s in Induction Reheating Process

2012 ◽  
Vol 192-193 ◽  
pp. 281-286 ◽  
Author(s):  
Nan Nan Song ◽  
Fan Zhang ◽  
You Feng He ◽  
Qiang Zhu
Keyword(s):  
Induction Heating ◽  
Process Parameters ◽  
Liquid Fraction ◽  
Quantitative Relationship ◽  
Heating Process ◽  
Time Interval ◽  
Short Time Interval ◽  
Compressor Wheel ◽  
Semi Solid ◽  
Reheating Process

Semi-solid processing of metallic alloys has been developing over the last 30 years. Millions of components are now manufactured by semi-solid processing. A semi-solid processing so called thixoforming requires reheating the feedstock to a semi-solid state in relatively short time interval with a uniform temperature distribution as well as an optimum liquid fraction. Microstructure, which makes significant impact on processing parameters and quality of the component, changes during the reheating process. The main objective of this study is to establish a quantitative relationship of the microstructure and the induction heating process parameters of the aluminum alloy 319s. This quantitative relationship is employed in the numerical simulation of calculating solid/liquid fraction changes during induction heating process. The simulation results are then successfully applied in aiding optimization of process parameters to make an automobile engine turbocharger compressor wheel, which has very complex geometry.

Steel Grades Adapted to the Thixoforging Process: Metallurgical Structures and Mechanical Properties

2006 ◽  
Vol 116-117 ◽  
pp. 712-716 ◽  
Author(s):  
Marc Robelet ◽  
Ahmed Rassili ◽  
Dirk Fischer
Keyword(s):  
Mechanical Properties ◽  
Liquid Fraction ◽  
Solidus Temperature ◽  
Process Temperature ◽  
Heating Process ◽  
Work Piece ◽  
Inductive Heating ◽  
Steel Grades ◽  
Automotive Part ◽  
Semi Solid

Thixoforming of steel offers the advantages of casting technology in combination with high mechanical strength that can only be achieved by forging. The progress in establishing this technology in industry depends on the success in the development of suitable steel grades. Recent investigations dealt with the development of steel grades that are especially adapted to the thixoforming process. For this, alloys were developed with a lower solidus temperature and a wider process temperature range compared to classic forging steels. In consequence, the inductive heating process is more tolerant to inaccuracies and for a given liquid fraction the process temperature window is easier to handle. It is desired to obtain great degrees of deformation at rather low forming forces as these parameters determine the size of the needed presses. This behaviour is affected by the present liquid fraction in the slug and the heat transfer between work piece and die. It was detected that variations of the forming force have a direct influence on the quality of the thixoformed parts. In order to make the thixoforming technology of steels competitive versus other forming technologies, the parts must show a favourable microstructure and thus, good in-use properties. In this paper various solutions are compared. The main results obtained in the optimization research, namely, the steel grades adapted to semi-solid forming, the resulting process parameters and the mechanical properties of thixoforming parts will be presented for two exemplary steel grades. By producing a real automotive part, thixoforging of steels with regard to the adapted materials and to the ongoing industrial implementation of this process is proved.

Semi-Solid Casting of Pure Magnesium

2019 ◽  
Vol 285 ◽  
pp. 464-469 ◽  
Author(s):  
Ulyate Andries Curle ◽  
Jeremias D. Wilkins
Keyword(s):  
Temperature Interval ◽  
Liquid Fraction ◽  
Thermodynamic Temperature ◽  
Casting Process ◽  
Pure Magnesium ◽  
Time Interval ◽  
Thermal Arrest ◽  
Solidification Temperature ◽  
Semi Solid ◽  
Solid Liquid

Semi-solid processing works on the principal of a solidification temperature interval of a substance. The substance is heated to a temperature within this interval so that there exists a related solid-liquid fraction ratio. The substance with this phase structure is then shaped by a forging or casting process. It has been stated before that it is impossible to semi-solid process and cast pure metals or eutectic alloys due to their thermodynamic temperature invariance, meaning that there is no temperature interval. It was demonstrated recently that it is possible to semi-solid casting high purity aluminium (Curle UA, Möller H, Wilkins JD. Scripta Materialia 64 (2011) 479-482) and the Al-Si binary eutectic (Curle UA, Möller H, Wilkins JD. Materials Letters 65 (2011) 1469-1472). The working principal is that there exists a time interval during thermal arrest during which solidification takes place with a solid-liquid fraction ratio until all the liquid is consumed upon cooling. The aim with this work is to demonstrate that pure magnesium can also be rheo-high pressure die cast (R-HPDC) with the system developed at the CSIR in South Africa. Magnesium is notoriously difficult to cast due to the thermal properties of magnesium. The metal was poured into a cup, processed for about 6 seconds after which it was HPDC into a plate. The microstructure of the casting consists of a structure that was solid and a structure that was liquid during thermal arrest at the time of casting.

scholarly journals Parameter Optimization and Prediction Model of Induction Heating for Large-Diameter Pipe

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiurong Fang ◽  
Jia Lu ◽  
Junfeng Wang ◽  
Jinhui Yang
Keyword(s):  
Prediction Model ◽  
Induction Heating ◽  
Process Parameters ◽  
Pipeline Steel ◽  
Large Diameter ◽  
Outer Wall ◽  
Design Parameters ◽  
Heating Process ◽  
Influence Of Process Parameters ◽  
Heating Device

The parameters of induction heating of large-diameter pipes have a direct effect on the final processing quality of the elbow, and the complexity of multifield coupling of magnetothermal force in induction heating can make it impossible to quantitatively optimize the design parameters of the induction heating device. In this paper, X80 pipeline steel induction heating is taken as the research object, and a corresponding numerical model is established. The influence of induction heating process parameters on the heating temperature of pipeline steel under the skin effect is determined. First, the influence of process parameters on the heating effect of pipeline steel is quantified by orthogonal test. Then, taking the optimum temperature difference between the inner and outer wall of X80 pipeline steel during the induction heating process as a target, the optimal process parameter set of the pipe induction heating is determined by using neural network genetic algorithm. Finally, comparing the relevant test criteria of the regression equation, the optimum mathematical prediction model of the outer wall temperature of the pipe induction heating process is obtained, which provides a theoretical basis for optimization of the process parameters of the pipe-based induction heating device.

Inductive Reheating of Steel Billets into the Semi-Solid State Based on Pyrometer Measurements

2006 ◽  
Vol 116-117 ◽  
pp. 734-737 ◽  
Author(s):  
Alexander Schönbohm ◽  
Rainer Gasper ◽  
Dirk Abel
Keyword(s):  
Solid State ◽  
Measurement Errors ◽  
Liquid Fraction ◽  
Solidus Temperature ◽  
Measurement Data ◽  
Heating Process ◽  
Production Environment ◽  
Loop Control ◽  
Control Scheme ◽  
Semi Solid

The aim of the paper is to demonstrate a control scheme by which it is possible to reproducibly reheat steel billets into the semi-solid state. Usually a heating program is used to reheat the billet into the semi-solid state. Our experiments showed that this control scheme leads to varying semi-solid fractions from one experiment to the next. To gain information about the billet’s state its temperature is often used since there is a known relationship between the temperature and the liquid fraction. Direct measurement of the temperature via thermocouples is not feasible in a production environment, therefore a radiation pyrometer has been used as a contact-less measurement device. The accuracy of the pyrometer depends heavily on the exact knowledge of the radiation coefficient, which can vary from billet to billet due to different surface properties and which is subject to change during the heating process. These uncertainties prohibit the implementation of a closed-loop control scheme since the exact temperature cannot be measured with the required accuracy. In order to be independent of the measurement errors the proposed control scheme only relies on the slope of the temperature. By detecting the distinct change of slope which occurs when the solidus temperature is crossed, the beginning of the melting process can be determined. The energy fed to the billet from this point onward determines the resulting liquid fraction. By detecting the entry into the solidusliquidus interval and then feeding the same amount of energy to each billet, it is guaranteed that the billet reaches the desired liquid fraction even by uncertain absolute value of the temperature and by small variations of the alloy composition. For the experiments the steel alloy X210 has been used and measurement data demonstrate the feasibility of the proposed control scheme.

scholarly journals Effect of Experimental Conditions on 7075 Aluminium Response during Thixoextrusion

2012 ◽  
Vol 504-506 ◽  
pp. 345-350 ◽  
Author(s):  
Adriana Neag ◽  
Véronique Favier ◽  
Mariana Pop ◽  
Eric Becker ◽  
Régis Bigot
Keyword(s):  
Aluminum Alloy ◽  
Microstructure Evolution ◽  
Deformation Behavior ◽  
Liquid Fraction ◽  
Heat Losses ◽  
Heating Process ◽  
Semisolid State ◽  
Experimental Conditions ◽  
Solid Aluminum ◽  
Semi Solid

The deformation behavior of semi-solid aluminum alloy is strongly dependent on the microstructure. This paper illustrates several experimental research works concerning thixoextrusion of 7075 aluminum alloy which was carried out at “Arts et Métiers ParisTech” of Metz. Inductive re-heating of the aluminum billet is the method used in order to obtain the target liquid fraction for thixoextrusion. To minimize the heat losses, a sample obtained from a direct extruded bar is inserted in a die for reheating in semisolid state and thixoextrusion. During the experimental re-heating process, the temperature was directly controlled by using thermocouples for temperature measurements in the sample and also in the die. The influence of different working ram speeds and reheating temperature on the microstructure evolution was studied by optical microscopy. The experimental results on extrusion load and microstructure evolution of the component are reported.

scholarly journals A non-intrusive model order reduction approach for multi-physics parametrized problems - Application to induction heating process

2021 ◽  
Author(s):  
Khouloud Derouiche ◽  
Francisco Chinesta ◽  
Monzer Daoud ◽  
Khalil Traidi
Keyword(s):  
Finite Element ◽  
Real Time ◽  
Induction Heating ◽  
Process Parameters ◽  
Dimensional Space ◽  
Computational Cost ◽  
Heating Process ◽  
Reduced Basis ◽  
Finite Element Software ◽  
Low Dimensional

Finite element modeling (FEM) has recently become the most attractive computational tool to predict and optimize many industrial problems. However, the FEM becomes ineffective as far as complex multi-physics parameterized problems, such as induction heating process, are concerned because of high computational cost. This work aims at studying the possibility of applying a new approach based on the reduced order modeling (ROM) to obtain approximate solutions of a parametric problem. Basically, the effect of induction heating process parameters on some physical quantities of interest (QoI) will be analyzed under the real-time constraint. To achieve this dimensionality reduction, a set of precomputed solutions is first collected, at some sparse points in the space domain and for a properly selected process parameters, by solving the full-order models implemented in the commercial finite element software FORGE®. A Proper Orthogonal Decomposition (POD) based reducedorder model is then applied to the collected data to find a low dimensional space onto which the solution manifold could be projected and an approximated solution for new process parameters could be efficiently computed in real time. Besides, the POD is applied to build a reduced basis and to compute their corresponding modal coefficients. It is then followed by artificial intelligence techniques for regression purpose, such as sparse Proper Generalized Decomposition, to fit the low dimensional POD modal coefficients. Hence, the problem can be solved with a much lower dimension compared to the initial one. It was shown that a good approximation of the QoI was provided, in low-data limit, using a single POD modal coefficient as a response for the regression methods. However, the obtained approximation accuracy needs to be enhanced.

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