Tube Press Hardening for Lightweight Design

2011 ◽  
Author(s):  
Reimund Neugebauer ◽  
Frank Schieck ◽  
Markus Werner
Keyword(s):  
Lightweight Design ◽  
Innovative Technology ◽  
Material Strength ◽  
Original Material ◽  
Heat Management ◽  
Forming Process ◽  
Press Hardening ◽  
Forming Technology ◽  
Process Reliability ◽  
The Media

Press hardening is an innovative technology being applied to meet the growing demands for both lightweight and crash performance qualities. To further increase the lightweight potential, closed profiles are being used. As a result, a method has been developed at the Fraunhofer Institute for Machine Tools and Forming Technology IWU which allows the integration of press hardening of tubes and closed profiles into the media-based forming process. Using this press hardening technology, the original material strength of 500 MPa can be increased to between 1200 and 1900 MPa, depending on the chosen material. The engineering of tube press hardening is more complex than other forming processes, specifically the time dependence in combination with heat management makes it difficult. Therefore the use of FEA is indispensible when dealing with aspects such as heat treatment, the forming process itself, the cooling caused by the gaseous forming media and the general heat management of the tooling. To control and improve the process and therefore the part quality and process reliability, all these factors and their dependencies have to be taken into account. In addition to 22MnB5, other manganese-boron alloyed steels and different heating strategies have been tested. Based on these experiments the process capability was successfully proven and technological limits were obtained. Current investigations are focused on realizing tailored properties thus creating areas with varied strength and ductility in a single part.

Basic Investigations of Non-Pre-Punched Joining by Forming of Aluminium Alloy and High Strength Steel with Shear-Clinching Technology

2014 ◽  
Vol 611-612 ◽  
pp. 1413-1420 ◽  
Author(s):  
Marion Merklein ◽  
Gerson Meschut ◽  
Martin Müller ◽  
Réjane Hörhold
Keyword(s):  
Impact Load ◽  
Lightweight Design ◽  
High Strength Steels ◽  
High Strength ◽  
Joining By Forming ◽  
Forming Technology ◽  
Process Reliability ◽  
Mechanical Clinching ◽  
Increasing Demand ◽  
The One

Facing a decreasing amount of resources on the one hand and an increasing demand for comfort on the other, more and more attention is being paid to sustainability and care for the environment. Particularly in the automotive sector, lightweight design principles continue to prosper rapidly. As a result, adjusted materials for different applications were developed. Due to the formation of intermetallic phases, most multi-material mixes cannot be welded and require adapted joining technologies. Mechanical joining technologies such as self-piercing riveting and mechanical clinching have proven effective methods of joining lightweight materials like aluminium and ductile steels. New high-strength steels are increasingly used in crash-sections, where limited deformation under impact load is required. These hot stamped steels have a very low elongation at break and therefore a low formability. Currently there is no joining by forming technology without pre-punching available using these grades of steels on die-side. The newly developed shear-clinching process is one possible method of joining this kind of material without additional elements. The fundamental idea of shear-clinching is a single-stage process in which pre-punching of the die-side material is performed by indirect shear-cutting and subsequent forming of the upper layer into this hole. This would immensely enlarge the application segment of mechanical clinching even if hot stamped steels are positioned on die-side. Fundamental studies are required to ensure process reliability and it is necessary to break down the joining process into fragments, like pre-punching and clinching with pre-punched sheet, and superpose them to form the combined procedure shear-clinching. This paper presents a detailed investigation of the sub-process clinching with pre-hole.

Internal Flow-Turning - An Innovative Technology for the Manufacture of Tailored Tubes

2015 ◽  
Vol 639 ◽  
pp. 65-70 ◽  
Author(s):  
Werner Homberg ◽  
Tim Rostek ◽  
Eugen Wiens
Keyword(s):  
Incremental Forming ◽  
Lightweight Design ◽  
Internal Flow ◽  
Dimensional Accuracy ◽  
Innovative Technology ◽  
Outer Diameter ◽  
Forming Technology ◽  
Automotive Parts ◽  
Material Utilisation

In order to optimise the material utilisation and improve the lightweight design of automotive parts tailored hollow profiles are needed, especially as semi-finished parts for hydroforming. Internal Flow-Turning is an innovative incremental forming technology which enables the manufacture of tubes featuring a varying wall thickness and a constant outer diameter. These characteristics facilitate the material feed at hydroforming processes significantly. In addition, the spinning-related forming technology improves the mechanical material properties, shape and dimensional accuracy, and the surface quality of parts produced.

Determination of the Active Medium Temperature in Media Based Press Hardening Processes

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Welf-Guntram Drossel ◽  
Norbert Pierschel ◽  
Alexander Paul ◽  
Klaus Katzfuß ◽  
Rico Demuth
Keyword(s):  
Active Medium ◽  
Lightweight Design ◽  
Temperature Curve ◽  
Work Piece ◽  
Gas Temperature ◽  
Forming Process ◽  
Element Analysis ◽  
Medium Temperature ◽  
Press Hardening ◽  
Active Media

Safety, lightweight design, and reduction of emissions are terms which are key issues in modern vehicle construction. These challenges can be met by new lightweight design strategies, e.g., by using lightweight materials and high-strength steels as well as innovative forming technologies such as media based press hardening (MBPH). MBPH as a sub-production technique of hydroforming is a tempered internal high-pressure forming process of closed profiles, which this article is about, or sheet metals by gaseous media. Due to the high process requirements (internal pressure up to 70 MPa and temperatures up to 1000 °C), it has not been possible to measure the temperature curve of the active medium in a reliable way until now. The aim of the research project described in this article was to develop an innovative measuring instrument to determine the gas temperature curve with a measuring frequency of at least 1 Hz. Analytical and numerical calculations have indicated that the active medium has a significant influence on the thermodynamic of the forming process. The finite element analysis (FEA) of the heat flow during the forming process has indicated that the influence of the gas on the cooling process of the work piece is about 15% of the total influence of the tool. Consequently, the active medium in media based press hardening processes is an important thermal influencing factor. Experiments have confirmed that it is possible to determine the calculated curve of the gas temperature and maximum temperatures of the active media up to 500 °C. The findings of these studies make a significant contribution to identifying and analyzing the complete temperature balance in tempered active media based forming processes.

Upscaling of foam forming technology for pilot scale

TAPPI Journal ◽  
2019 ◽  
Vol 18 (8) ◽  
Author(s):  
JANI LEHMONEN ◽  
TIMO RANTANEN ◽  
KARITA KINNUNEN-RAUDASKOSKI
Keyword(s):  
Production Efficiency ◽  
Strength Loss ◽  
Pilot Scale ◽  
Foam Density ◽  
Forming Process ◽  
Production Scale ◽  
Forming Technology ◽  
Wet Pressing ◽  
Foam Forming ◽  
Board Industry

The need for production cost savings and changes in the global paper and board industry during recent years have been constants. Changes in the global paper and board industry during past years have increased the need for more cost-efficient processes and production technologies. It is known that in paper and board production, foam typically leads to problems in the process rather than improvements in production efficiency. Foam forming technology, where foam is used as a carrier phase and a flowing medium, exploits the properties of dispersive foam. In this study, the possibility of applying foam forming technology to paper applications was investigated using a pilot scale paper forming environment modified for foam forming from conventional water forming. According to the results, the shape of jet-to-wire ratios was the same in both forming methods, but in the case of foam forming, the achieved scale of jet-to-wire ratio and MD/CD-ratio were wider and not behaving sensitively to shear changes in the forming section as a water forming process would. This kind of behavior would be beneficial when upscaling foam technology to the production scale. The dryness results after the forming section indicated the improvement in dewatering, especially when foam density was at the lowest level (i.e., air content was at the highest level). In addition, the dryness results after the pressing section indicated a faster increase in the dryness level as a function of foam density, with all density levels compared to the corresponding water formed sheets. According to the study, the bonding level of water- and foam-laid structures were at the same level when the highest wet pressing value was applied. The results of the study show that the strength loss often associated with foam forming can be compensated for successfully through wet pressing.

Schwingungsüberlagertes Axialformen/Superimposed Oscillated Axial Forming

2020 ◽  
Vol 110 (11-12) ◽  
pp. 838-843
Author(s):  
Philipp Müller ◽  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Hendrik Vogt ◽  
Daniel Rosenbusch ◽  
...  
Keyword(s):  
Surface Quality ◽  
Economic Importance ◽  
Combined Effect ◽  
Wird Eine ◽  
Forming Force ◽  
Forming Process ◽  
Forming Technology ◽  
Great Economic Importance ◽  
Gear Geometry

Techniken zur Steigerung der Formgebungsgrenzen in der Umformtechnik sind von hoher wirtschaftlicher Bedeutung. In dieser Arbeit wird eine Schwingungsüberlagerung im Krafthauptfluss eines Axialformprozesses zur Ausprägung einer Verzahnungsgeometrie untersucht. Die Auswirkungen der Schwingung auf die erzielbare Ausfüllung der Zahnkavitäten werden analysiert sowie die Parameter Schmierung und Oberflächengüte der Halbzeuge in ihrer kombinierten Wirkung untersucht. Es konnte eine Reduzierung der mittleren Umformkraft sowie eine Erhöhung der Formfüllung festgestellt werden. Techniques for extending the production limits in forming technology are of great economic importance. In this research, a superimposed oscillation in the main force flow of an axial forming process to form an axial gear geometry is investigated. The effects of the superimposed oscillation on the achievable form-filling of the tooth cavities are analyzed and the parameters lubrication and surface quality of the semi-finished products are investigated in their combined effect. A reduction of the averaged forming force as well as an increase of the form-filling could be achieved.

Numerical Simulation and Process Optimization of Automotive Friction Materials in Warm Pressing Forming

2013 ◽  
Vol 788 ◽  
pp. 57-60
Author(s):  
Chun Cao ◽  
Chun Dong Zhu ◽  
Chen Fu
Keyword(s):  
Process Optimization ◽  
Heating Temperature ◽  
Maximum Energy ◽  
Heating Time ◽  
Product Performance ◽  
Forming Process ◽  
Friction Materials ◽  
Forming Technology ◽  
The Relationship ◽  
Temperature Heating

Warm pressing forming technology has been gradually applied to the forming of automotive friction materials. How to ensure product performance to achieve the target at the same time achieve the maximum energy saving is the research focus of this study. In this paper, by using finite element method, the field of automotive friction materials in warm pressing forming was analyzed, reveals the relationship between the temperature field and the heating temperature/heating time. Furthermore, the energy consumption was analyzed and compared it with hot pressing forming process. The results will have significant guiding to the process optimization in warm pressing forming.

Coupled Thermo-Mechanical FEA of Three-Roll Cross Rolling Process for Rings with Small-Hole and Deep Groove

2012 ◽  
Vol 560-561 ◽  
pp. 846-852 ◽  
Author(s):  
Qi Ma ◽  
Lin Hua ◽  
Dong Sheng Qian
Keyword(s):  
Rolling Process ◽  
Small Hole ◽  
Fe Model ◽  
Forming Process ◽  
Software Environment ◽  
Cross Rolling ◽  
Design And Optimization ◽  
Forming Technology ◽  
Deep Groove ◽  
Plastic Forming

Ring parts with small-hole and deep groove such as duplicate gear and double-side flange, are widely used in various engineering machineries. Three-roll cross rolling (TRCR) is a new advanced plastic forming technology for the processing of rings with small-hole and deep groove. In this paper, a 3D coupled thermo-mechanical FE model for TRCR of ring with small-hole and deep groove is established under ABAQUS software environment. By simulation and analysis, the evolution and distribution laws of strain and temperature in the forming process are revealed, and the effects of the key process parameters on the deformation uniformity are explored. The results provide valuable guideline for the technological parameter design and optimization.

Flexible Stretch Forming Technology for Sheet Metal Based on Discrete-Gripper and Multi-Point Die

2014 ◽  
Vol 556-562 ◽  
pp. 460-463 ◽  
Author(s):  
Xue Chen ◽  
Ming Zhe Li ◽  
Wen Hua Liu ◽  
Zhi Qiang Hou
Keyword(s):  
Sheet Metal ◽  
Experimental Results ◽  
Shape Error ◽  
Stretch Forming ◽  
Forming Process ◽  
Structural Composition ◽  
Forming Technology ◽  
Working Principle ◽  
Material Utilization

To solve the problem of low material utilization in traditional stretch forming process, a flexible stretch forming method was proposed, which can be realized by interaction of the multi-point stretch forming die with discrete-gripper stretch forming machine. The principle and characteristics of sheet metal flexible stretch forming technology was introduced, structural composition and working principle of the multi-point stretch forming die and discrete-gripper stretch forming machine were expounded, and the technology experiments was carried out with a self-designed flexible stretch forming technology equipment for sheet metal. The experimental results indicate that structure of multi-point stretch forming die and discrete-gripper stretch forming machine are reasonable, and flexible stretch forming technology can be realized by above-mentioned die and machine, stretch forming parts has a good quality and its shape error can satisfy requirements of production.

Microstructural Effect and Material Homogenization of Thermal-Hydroforming Magnesium Alloy Tubes

2011 ◽  
Vol 465 ◽  
pp. 459-462 ◽  
Author(s):  
Lin Wang ◽  
Luen Chow Chan ◽  
Ting Fai Kong
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Tensile Tests ◽  
Heat Treatment Condition ◽  
Material Strength ◽  
Forming Process ◽  
Engineering Strain ◽  
Treatment Conditions ◽  
Metal Forming Process ◽  
Microstructural Effect

The microstrctural evolution pre and post heat treatment is critical to achieve a successful product for metal forming process. This paper aims to investigate the microstructual effect of the magnesium alloy tubes undergone various heat treatment conditions to achieve material homogenization. The heat treatment conditions under various periods of time (1, 2, 6, 12 and 30 hours) at 400 °C were employed to investigate the microstructural effect on hydroforming magnesium tubes. The greatly reduced impurity embedded in grain boundaries and more uniform grain sizes do indicate the improvement of material strength and ductility. To validate the conclusion, corresponding tensile tests at the different temperatures (20 °C and 200 °C) were carried out. The increased engineering strain in two directions (hoop and longitudinal) implies that the microstructural evolution is unquestionably useful to enhance the ductility of the magnesium tubes. Subsequently, the tubes after optimal heat treatment condition at 400 °C for 6 hours were used to further carry out the thermal hydroforming process for validation. The defect-free hydroformed tubes were produced under the same working condition, which is unable to be achieved for tubes without the heat-treatment process.

Principle and Simulation Study on Multi Point-Single Point Incremental Combined Forming for Sheet Metal

2009 ◽  
Vol 626-627 ◽  
pp. 273-278 ◽  
Author(s):  
X.J. Li ◽  
Ming Zhe Li ◽  
C.G. Liu ◽  
Zhong Yr Cai
Keyword(s):  
Sheet Metal ◽  
Single Point ◽  
Experimental Result ◽  
Work Piece ◽  
The Novel ◽  
Forming Process ◽  
Explicit Finite Element ◽  
Forming Defect ◽  
Forming Technology ◽  
Elastic Cushion

Based on Multi-Point (MP) forming technology and Single-Point Incremental (SPI) forming technology, MP-SPI combined forming method for sheet metal is proposed, the principle and two different forming techniques are illustrated firstly. Then the paper is focused on numerical analysis for the novel forming technique with explicit Finite Element (FE) algorithm. During simulation of spherical work-piece, dimpling occurs as a main forming defect in MP-SPI combined forming process. Simulation results show that the dimpling defect can be suppressed effectively by using elastic cushion. An appropriate thickness of elastic cushion is necessary to prevent dimpling. And also the deformation of the work-piece is sensitive to the shape of elastic cushion. The combined forming test shows that the numerical simulation result is closed to the experimental result.

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