Series Production of Thixoformed Steel Parts

2006 ◽  
Vol 116-117 ◽  
pp. 686-689 ◽  
Author(s):  
Bernd Arno Behrens ◽  
Dirk Fischer ◽  
Bjoern Haller ◽  
Ahmed Rassili ◽  
Jean Christophe Pierret ◽  
...  
Keyword(s):  
Tool Material ◽  
Heating System ◽  
Practical Experience ◽  
Inductive Heating ◽  
Special Role ◽  
Series Production ◽  
Forming Process ◽  
Steel Grades ◽  
Semi Solid ◽  
Automotive Steel

In recent years several attempts were made to transfer the thixoforming technology of steel parts into industrial applicable processes. This paper gives an overview about the progress of a European consortium that established a fully automated thixoforming process for the series production of automotive steel parts. Due to the multi-faceted nature of this technology, problems concerning the development of suitable steel grades and tool materials as well as the development and application of an inductive heating system, a handling unit and of a complex forming tool had to be solved. Besides the development of adapted steel grades and the inductive heating, the handling of the semi solid billets plays a special role because during the manipulation of the parts from the heating station into the tool a loss of heat is unavoidable. Furthermore, scaling of the parts must be prevented. By means of a fully automated process line existing constraints were reduced and the forming process is kept reproducible. Improved silicon nitride composites have been developed as a tool material, which show good mechanical properties in combination with an acceptable chemical stability at the occurring process temperatures as well as in contact with semi solid steel. Basing on the practical experience a comparison of the thixoforming technology to existing processes and an outlook for the future are given.

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.

Investigations on Thermal Influences for Thixoforging and Thixojoining of Steel Components

2008 ◽  
Vol 141-143 ◽  
pp. 37-42 ◽  
Author(s):  
René Baadjou ◽  
Frederik Knauf ◽  
Gerhard Hirt
Keyword(s):  
Collaborative Research ◽  
Tool Material ◽  
Solid Matrix ◽  
Research Centre ◽  
Precursor Material ◽  
Temperature Development ◽  
Steel Grades ◽  
Fundamental Research ◽  
Semi Solid ◽  
Forming Tools

At the Institute of Metal Forming (IBF) current investigations within the framework of the Collaborative Research Centre 289 are mainly concentrated on forming of semi-solid precursor material of the steel grades X210CrW12 and 100Cr6. One important task is the precise temperature for the composition of solid and liquid phase fraction in the preheated billet. Experimental measurements and numerical simulations show significant heat losses during transport of the billet and after its insertion into the die. These developing temperature gradients influence strongly the resulting temperature field in the formed component. In case of the forming tools the critical increase of the temperature depending on the tool material is shown. As fundamental research in the field of thixojoining the temperature development of the inserts is analysed and demonstrates the feasibility of joining higher and lower melting materials into the semi-solid matrix.

scholarly journals Evaluation of Heating Technique of Deformed Reinforcement Using High-Frequency Induction Heating System

2021 ◽  
Vol 11 (11) ◽  
pp. 4947
Author(s):  
Myung-hwan Lim ◽  
Changhee Lee
Keyword(s):  
Reinforced Concrete ◽  
Temperature Rise ◽  
High Frequency ◽  
Thermal Conduction ◽  
Rapid Heating ◽  
Heating System ◽  
Inductive Heating ◽  
Reinforced Steel ◽  
Induction Heating System ◽  
High Frequency Induction

To improve recycling quality, it is necessary to develop a demolition technology that can be combined with existing crushing methods that employ large shredding-efficient equipment. The efficient collection of bones in a segmentation dismantling method must be considered according to the procedure. Furthermore, there is a need for the development of partial dismantling technologies that enable efficient remodeling, maintenance, and reinforcement. In this study, we experimentally investigated the temperature-rise characteristics of reinforced concrete through partial rapid heating during high-frequency induced heating. Accordingly, the chemical and physical vulnerability characteristics of the reinforced concrete were verified by studying the thermal conduction on the surface of the rebars and the cracks caused by the thermal expansion pressure of the rebars. Furthermore, we aimed to verify the applicability of the proposed technology by specifying the vulnerability range of the reinforced concrete based on the heating range, as well as the appropriate energy consumption. We investigated the temperature rise and temperature distribution characteristics of the rebar surfaces based on diameter, length, bar placement conditions, heating distance, heating coil location, and output, using reinforced steel of grade SD345. Maximum powers of 5, 6, and 10 kW, and inductive heating were used to achieve satisfactory results.

scholarly journals Artificial neural network for modeling and investigating the effects of forming tool characteristics on the accuracy and formability of thin aluminum alloy blanks when using SPIF

2021 ◽  
Author(s):  
Sherwan Mohammed Najm ◽  
Imre Paniti
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Process Parameters ◽  
Single Point ◽  
Tool Material ◽  
Deformation Mode ◽  
Geometric Accuracy ◽  
Forming Process ◽  
Tool Shape ◽  
Artificial Neural

AbstractIncremental Sheet Forming (ISF) has attracted attention due to its flexibility as far as its forming process and complexity in the deformation mode are concerned. Single Point Incremental Forming (SPIF) is one of the major types of ISF, which also constitutes the simplest type of ISF. If sufficient quality and accuracy without defects are desired, for the production of an ISF component, optimal parameters of the ISF process should be selected. In order to do that, an initial prediction of formability and geometric accuracy helps researchers select proper parameters when forming components using SPIF. In this process, selected parameters are tool materials and shapes. As evidenced by earlier studies, multiple forming tests with different process parameters have been conducted to experimentally explore such parameters when using SPIF. With regard to the range of these parameters, in the scope of this study, the influence of tool material, tool shape, tool-end corner radius, and tool surface roughness (Ra/Rz) were investigated experimentally on SPIF components: the studied factors include the formability and geometric accuracy of formed parts. In order to produce a well-established study, an appropriate modeling tool was needed. To this end, with the help of adopting the data collected from 108 components formed with the help of SPIF, Artificial Neural Network (ANN) was used to explore and determine proper materials and the geometry of forming tools: thus, ANN was applied to predict the formability and geometric accuracy as output. Process parameters were used as input data for the created ANN relying on actual values obtained from experimental components. In addition, an analytical equation was generated for each output based on the extracted weight and bias of the best network prediction. Compared to the experimental approach, analytical equations enable the researcher to estimate parameter values within a relatively short time and in a practicable way. Also, an estimate of Relative Importance (RI) of SPIF parameters (generated with the help of the partitioning weight method) concerning the expected output is also presented in the study. One of the key findings is that tool characteristics play an essential role in all predictions and fundamentally impact the final products.

Study on Rheo-Diecasting for In Situ Synthesized Mg2Si/AM60 Composites

2011 ◽  
Vol 383-390 ◽  
pp. 707-711
Author(s):  
Hong Yan ◽  
Yong Hu ◽  
Xiao Quan Wu
Keyword(s):  
Die Casting ◽  
Casting Machine ◽  
Chinese Script ◽  
Matrix Composites ◽  
Forming Process ◽  
Magnesium Matrix ◽  
Magnesium Matrix Composites ◽  
Mechanical Stirring ◽  
Semi Solid

Magnesium alloys have high specific strength, specific stiffness, excellent thermal conductivity and casting properties, which have a great prospects development in the industry, However, its low plasticity and ductility limited its application. Magnesium matrix composites can effectively improve its performance. Magnesium alloy die-casting is the main forming process, the conventional high-pressure die-casting (HPDC) defects in multi-cavity type, easy to volume gas, non-heat-treated. Compared with HPDC, the rheo-diecasting (RDC) process has been greatly developed for near-net shape components. In this paper, Mg2Si /AM60 composites is fabricated by in-situ synthesis and semi-solid magnesium matrix composites which are rheoformed in the die-casting machine are prepared by mechanical stirring. The results indicate that the microstructure of composites is non-dendritic and Chinese script type Mg2Si are fine distributed. The fundamental morphology of microstructure by HPDC is dendrite and liquid-phase distributed between dendrite irregularly. The RDC samples have close-to-zero porosity, less segregation, the most of semi-solid of microstructure in rheo-diecasting is spherical or as-spherical structure.

On the suitability of induction heating system for metal additive manufacturing

2020 ◽  
Vol 235 (1-2) ◽  
pp. 219-229 ◽  
Author(s):  
Gourav K Sharma ◽  
Piyush Pant ◽  
Prashant K Jain ◽  
Pavan K Kankar ◽  
Puneet Tandon
Keyword(s):  
Energy Source ◽  
Additive Manufacturing ◽  
Induction Heating ◽  
Low Cost ◽  
Three Dimensional ◽  
Experimental System ◽  
Heating System ◽  
Industrial Applications ◽  
Metallic Materials ◽  
Semi Solid

Induction heating is a non-contact-based energy source that has the potential to quickly melt the metal and become the alternate energy source that can be used for additive manufacturing. At present, induction heating is widely used in various industrial applications such as melting, preheating, heat treatment, welding, and brazing. The potential of this source has not been explored in the additive manufacturing domain. However, the use of induction heating in additive manufacturing could lead to low-cost part fabrication as compared to other energy sources such as laser or electron beam. Therefore, this study explores the feasibility of this energy source in additive manufacturing for fabricating parts of metallic materials. An experimental system has been developed by modifying an existing delta three-dimensional printer. An induction heater coil has been incorporated to extruder head for semi-solid processing of the metal alloy. In order to test the viability of the developed system, aluminium material in the filament form has been processed. Obtained results have shown that the induction heating–based energy source is capable of processing metallic materials having a melting point up to 1000° C. The continuous extrusion of the material has been achieved by controlling the extruder temperature using a proportional integral derivative–based controller and k-type thermocouple. The study also discusses various issues and challenges that occurred during the melting of metal with induction heating. The outcomes of this study may be a breakthrough in the area of metal-based additive manufacturing.

Influence of Nitrogen on Oxidation Resistance of Automotive Steel Grades

2020 ◽  
Vol 835 ◽  
pp. 83-92
Author(s):  
Saeed Ghali ◽  
Mamdouh Eissa ◽  
Hoda El-Faramawy ◽  
Azza Ahmed ◽  
Fathy Baiomy ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Stainless Steels ◽  
Oxidation Process ◽  
Diffusion Mechanism ◽  
Solution Treatment ◽  
Mass Gain ◽  
Optical Microscope ◽  
Partial Replacement ◽  
Steel Grades ◽  
Automotive Steel

With the objective of partial and total replacement of nickel by nitrogen in austenitic exhausted valve steel X45CrNiW18-9, a program of work with series of experimental heats was designed. Experimental heats were carried out in 10 Kg. induction furnace under nitrogen pressure. The chemical composition of produced stainless steels was determined. The produced automotive steel grades were forged. The nitrogen contents were determined. The produced forged stainless steels were subjected to solution treatment at 1050 °C for 1 hour, followed by water cooling. Isothermal oxidation test is used to detect the behavior of new grades at different temperatures in air for solution treated stainless steels. The mass gain was measured for samples exposed to air at temperatures (500 °C, 600 °C, 700 °C, 800°C) for different time intervals, up to 1000 hrs. The oxide layer thickness for two selected steels was investigated by using optical microscope. XRD was used to detect types of oxides which are formed during oxidation process at 800 °C for 1000 hrs for represented investigated exhausted valve steels. Scanning Electron Microscope was used to make scan steels surface, after heating at 500 °C and 800 °C for l000hr. The mechanism of the oxidation of developed steels was investigated. It was found controlled by diffusion mechanism and the kinetic of oxidation process is parabolic. Oxidation rate of the investigated stainless steels for times, up to 8 h and between 200 andl000 h, at all investigated temperatures (500 °C - 800 °C), is parabolic and the oxidation is diffusion controlled. While in the time region 10 to 200 h, it obeys combined mechanisms. Partial replacement of nickel, by nitrogen, improves the oxidation resistance in air at temperature range 500°C - 800°C.

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