Manufacturing of Hybrid Al-Cu-Heatsinks by Combining Powder Pressing with Thixoforming

2022 ◽  
Vol 327 ◽  
pp. 231-237
Author(s):  
Marco Speth ◽  
Mathias Liewald ◽  
Kim Rouven Riedmüller ◽  
Laura Schomer
Keyword(s):  
Aluminium Alloy ◽  
Process Parameters ◽  
Material Properties ◽  
Liquid Fraction ◽  
Heat Sinks ◽  
Functional Requirements ◽  
Transition Zones ◽  
Porous Copper ◽  
Powder Pressing ◽  
Semi Solid

Hybrid material structures allow different material properties to be combined in one single component and thus to meet high functional requirements. When manufacturing such hybrid components, particular attention must be paid to the transition zones between metallic composite partners. These transition zones need to show largely homogeneous and materially bonded structures in order to ensure ideal transmission of the material properties and to prevent component failure due to material defects. In this respect, this paper focuses on a newly developed process in which a powder metallurgical route is combined with semi-solid forming technology. Here, porous copper green bodies are inserted into a forming die and subsequently forged together with a semi-solid aluminium alloy. In this way, it was tried to combine both metal materials into a material locking or at least into a form locking manner in order to achieve ideal material properties in the final hybrid component. The aim of this paper is to find suitable process parameters to infiltrate the porous copper inlay with the semi-solid aluminium alloy during thixoforming. Therefore, different process parameters such as varying liquid fraction of the aluminium alloy and different densities of the green bodies were examined during the production of simply shaped hybrid Al-Cu-components. Afterwards the infiltration depth and produced microstructure of the components was analysed. In the future, this process allows for producing aluminium-copper hybrid heat sinks with improved heat transfer properties compared to conventional produced heat sinks.

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.

scholarly journals A FEM-Based 2D Model for Simulation and Qualitative Assessment of Shot-Peening Processes

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2784
Author(s):  
Georgios Maliaris ◽  
Christos Gakias ◽  
Michail Malikoutsakis ◽  
Georgios Savaidis
Keyword(s):  
Process Parameters ◽  
Material Properties ◽  
Shot Peening ◽  
Qualitative Assessment ◽  
Experimental Investigations ◽  
Elastoplastic Material ◽  
Size Distributions ◽  
User Friendly ◽  
The Impact ◽  
2D Model

Shot peening is one of the most favored surface treatment processes mostly applied on large-scale engineering components to enhance their fatigue performance. Due to the stochastic nature and the mutual interactions of process parameters and the partially contradictory effects caused on the component’s surface (increase in residual stress, work-hardening, and increase in roughness), there is demand for capable and user-friendly simulation models to support the responsible engineers in developing optimal shot-peening processes. The present paper contains a user-friendly Finite Element Method-based 2D model covering all major process parameters. Its novelty and scientific breakthrough lie in its capability to consider various size distributions and elastoplastic material properties of the shots. Therewith, the model is capable to provide insight into the influence of every individual process parameter and their interactions. Despite certain restrictions arising from its 2D nature, the model can be accurately applied for qualitative or comparative studies and processes’ assessments to select the most promising one(s) for the further experimental investigations. The model is applied to a high-strength steel grade used for automotive leaf springs considering real shot size distributions. The results reveal that the increase in shot velocity and the impact angle increase the extent of the residual stresses but also the surface roughness. The usage of elastoplastic material properties for the shots has been proved crucial to obtain physically reasonable results regarding the component’s behavior.

Schadenserfassung auf Radsatzlaufflächen/Defect detection on wheelset treads – Measurement of Magnetic Barkhausen Noise to detect varying workpiece conditions

2019 ◽  
Vol 109 (11-12) ◽  
pp. 811-815
Author(s):  
B. Denkena ◽  
B. Bergmann ◽  
H. Blech
Keyword(s):  
Acoustic Emission ◽  
Process Parameters ◽  
Defect Detection ◽  
Material Properties ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Optimal Process ◽  
Process Reliability

Unterschiedliche Belastungshistorien von Eisenbahnrädern führen zu Werkstoffveränderungen in der Lauffläche. Diese verursachen sporadisches Werkzeugversagen und verringern so die Prozesssicherheit. Die Messung der Material- und Prozesseigenschaften mit Barkhausenrauschen und Körperschall erlauben, individuelle Bearbeitungsparameter für jedes Exemplar festzulegen. Gezeigt werden die Herausforderungen in der Radsatzbearbeitung, und welche Informationen sich durch die Messtechniken gewinnen lassen.   Different load histories of train wheels lead to high variance of material properties on the running tread. Those cause unpredictable tool break and reduce process reliability. The measurement of magnetic Barkhausen noise and acoustic emission allow to gain information of the workpiece and the running process, to find optimal process parameters for the reconditioning of every individual wheel. Typical issues in train wheel machining and results of measurements are presented.

Effect of material properties and process parameters on quality of friction stir forming

2021 ◽  
Vol 70 ◽  
pp. 553-559
Author(s):  
Francesco Gagliardi ◽  
Mahsa Navidirad ◽  
Giuseppina Ambrogio ◽  
Wojciech Z. Misiolek
Keyword(s):  
Process Parameters ◽  
Material Properties ◽  
Friction Stir

scholarly journals Analysis of the influence of position of welding materials on the FSW seams properties for three dissimilar aluminium alloy

2018 ◽  
Vol 178 ◽  
pp. 03003 ◽  
Author(s):  
Ana Bosneag ◽  
Marius Adrian Constantin ◽  
Eduard Niţu ◽  
Monica Iordache
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Arc Welding ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Workpiece Material ◽  
Friction Stir ◽  
Welding Joints ◽  
Welding Materials

Friction Stir Welding, abbreviated FSW is a new and innovative welding process. This welding process is increasingly required, more than traditional arc welding, in industrial environment such us: aeronautics, shipbuilding, aerospace, automotive, railways, general fabrication, nuclear, military, robotics and computers. FSW, more than traditional arc welding, have a lot of advantages, such us the following: it uses a non-consumable tool, realise the welding process without melting the workpiece material, can be realised in all positions (no weld pool), results of good mechanical properties, can use dissimilar materials and have a low environmental impact. This paper presents the results of experimental investigation of friction stir welding joints to three dissimilar aluminium alloy AA2024, AA6061 and AA7075. For experimenting the value of the input process parameters, the rotation speed and advancing speed were kept the same and the position of plates was variable. The exit date recorded in the time of process and after this, will be compared between them and the influence of position of plate will be identified on the welding seams properties and the best position of plates for this process parameters and materials.

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.

scholarly journals Weldability Investigation and Optimization of Process Variables for TIG-Welded Aluminium Alloy (AA 8006)

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
T. Sathish ◽  
S. Tharmalingam ◽  
V. Mohanavel ◽  
K. S. Ashraff Ali ◽  
Alagar Karthick ◽  
...  
Keyword(s):  
Experimental Design ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Surface Hardness ◽  
Weight Ratio ◽  
Welding Process ◽  
Tig Welding ◽  
Low Weight ◽  
Superior Corrosion Resistance ◽  
Welding Processes

Aluminium and its alloys play a significant role in engineering material applications due to its low weight ratio and superior corrosion resistance. The welding of aluminium alloy is challenging for the normal conventional arc welding processes. This research tries to resolve those issues by the Tungsten Inert Gas welding process. The TIG welding method is an easy, friendly process to perform welding. The widely applicable wrought aluminium AA8006 alloy, which was not considered for TIG welding in earlier studies, is considered in this investigation. For optimizing the number of experiments, the Taguchi experimental design of L9 orthogonal array type experimental design/plan was employed by considering major influencing process parameters like welding speed, base current, and peak current at three levels. The welded samples are included to investigate mechanical characterizations like surface hardness and strengths for standing tensile and impact loading. The results of the investigation on mechanical characterization of permanent joint of aluminium AA8006 alloy TIG welding were statistically analyzed and discussed. The 3D profilometric images of tensile-tested specimens were investigated, and they suggested optimized process parameters based on the result investigations.

scholarly journals Longitudinal Residual Stress Analysis in AA2024-T3 Friction Stir Welding

2013 ◽  
Vol 7 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Pierpaolo Carlone ◽  
Gaetano S. Palazzo
Keyword(s):  
Friction Stir Welding ◽  
Residual Stresses ◽  
Process Parameters ◽  
Material Properties ◽  
Stress Measurement ◽  
Dynamic Performance ◽  
Contour Method ◽  
Influence Of Process Parameters ◽  
Friction Stir ◽  
Longitudinal Residual Stress

Friction Stir Welding (FSW) is an innovative solid-state joining process, which is gaining a great deal of attention in several applicative sectors. The opportune definition of process parameters, i.e. minimizing residual stresses, is crucial to improve joint reliability in terms of static and dynamic performance. Longitudinal residual stresses, induced by FSW in AA2024-T3 butt joints, have been inferred by means of a recently developed technique, namely the contour method. Two approaches to stress measurement have been adopted; the former is based on the assumption of uniform material properties, the latter takes into account microstructural effects and material properties variations in the welding zones. The influence of process parameters, namely rotating and welding speeds, on stress distribution is also discussed.

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