scholarly journals Influence of Tailored Surfaces and Superimposed-Oscillation on Sheet-Bulk Metal Forming Operations

2020 ◽  
Vol 4 (2) ◽  
pp. 41
Author(s):  
Bernd-Arno Behrens ◽  
Wolfgang Tillmann ◽  
Dirk Biermann ◽  
Sven Hübner ◽  
Dominic Stangier ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
High Strength Steels ◽  
High Strength ◽  
Compression Tests ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Tailored Surfaces ◽  
High Feed

Producing complex sheet metal components in fewer process steps motivated the development of the innovative forming process called sheet-bulk metal forming (SBMF). In this process, sheet metal forming and bulk-metal forming are combined to create a unique forming process in which a component with external and internal gearing is produced in three production steps. However, the high degrees of deformation that occur using high-strength steels and the number of different process steps result in high process forces, strongly limiting the service life of tools. To reduce the forming force during SBMF processes, tool and process modifications were investigated. Therefore, plane-strain compression tests were conducted to examine the influence of a CrAlN PVD coating and tailored surfaces produced by high-feed milling (HF) of tool-active elements on the material flow of the specimens. In addition to the tool-sided modifications, the influence of an oscillation overlay during the forming process was investigated. Based on the results of the compression tests, the surfaces of the active tool elements of the SBMF process were modified in order to transfer the basic experimental results to the production of a functional component. The friction is thus adapted locally in the SBMF process.

scholarly journals Extension of the forming limits of extrusion processes in sheet-bulk metal forming for production of minute functional elements

2020 ◽  
Vol 7 ◽  
pp. 9 ◽  
Author(s):  
Florian Pilz ◽  
Johannes Henneberg ◽  
Marion Merklein
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Extrusion Process ◽  
Process Conditions ◽  
Functional Elements ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Lateral Extrusion ◽  
Component Design ◽  
Tailored Surfaces

Increasing demands in modern production pose new challenges to established forming processes. One approach to meet these challenges is the combined use of established process classes such as sheet and bulk forming. This innovative process class, also called sheet-bulk metal forming (SBMF), facilitates the forming of minute functional elements such as lock toothing and gear toothing on sheet-metal bodies. High tool loads and a complex material flow that is hard to control are characteristic of SBMF. Due to these challenging process conditions, the forming of functional elements is often insufficient and necessitates rework. This negatively affects economic efficiency. In order to make use of SBMF in industrial contexts, it is necessary to develop measures for improving the forming of functional elements and thereby push existing forming boundaries. This paper describes the design and numerical replication of both a forward and a lateral extrusion process so as to create involute gearing in combination with carrier teeth. In a combined numerical-experimental approach, measures for extending the die filling in sheet-metal extrusion processes are identified and investigated. Here, the focus is on approaches such as process parameters, component design and locally adjusted tribological conditions; so-called ‘tailored surfaces’. Based on the findings, fundamental mechanisms of action are identified, and measures are assessed with regard to their potential for application. The examined approaches show their potential for improving the forming of functional elements and, consequently, the improvement of geometrical accuracies in functional areas of the workpieces.

Experimental Study on Galling Behavior of Advanced High Strength Steel in Sheet Metal Forming

2012 ◽  
Vol 502 ◽  
pp. 36-40
Author(s):  
Ying Ke Hou ◽  
Shu Hui Li ◽  
Yi Xi Zhao ◽  
Zhong Qi Yu
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Sheet Material ◽  
High Strength Steels ◽  
High Strength ◽  
Forming Process ◽  
Advanced High Strength Steels ◽  
Sheet Materials ◽  
Materials Used

Galling is a known failure mechanism in many sheet metal forming processes. It limits the lifetime of tools and the quality of the products is affected. In this study, U-channel stamping experiments are performed to investigate the galling behavior of the advanced high strength steels in sheet metal forming . The sheet materials used in the tests are DP590 and DP780. In addition to the DP steels, the mild steel B170P1 is tested as a reference material in this study. Experimental results indicate that galling problem becomes severe in the forming process and the galling tendency can be divided into three different stages. The results also show that sheet material and tool hardness have crucial effects on galling performance in the forming of advanced high strength steels. In this study, DP780 results in the most heaviest galling among the three types of sheet materials. Galling performance are improved with increased hardness of the forming tool.

scholarly journals New Multistage Sheet-Bulk Metal Forming Process Using Oscillating Tools

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 617 ◽  
Author(s):  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Philipp Müller ◽  
Hans-Bernward Besserer ◽  
Gregory Gerstein ◽  
...  
Keyword(s):  
Plane Strain ◽  
Metal Forming ◽  
Compression Tests ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Mould Filling ◽  
Ring Compression ◽  
Metal Forming Process ◽  
Biaxial Flow

A new sheet-bulk metal forming process for the production of bulk components out of a flat sheet has been developed. Superimposed oscillation has been applied to the new process. By this means, process limits regarding better mould filling were expanded, and forming forces could be reduced. In order to investigate the effects of superimposed oscillation on material behaviour, plane strain and ring compression tests were carried out. The superimposed oscillated plane strain compression test showed a reduction in biaxial flow stress and thus in plastic work. Furthermore, reduced friction and roughness were verified in ring compression tests using superimposed oscillation.

Material Flow in Sheet-Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 1035-1040 ◽  
Author(s):  
Ulrich Vierzigmann ◽  
Johannes Koch ◽  
Marion Merklein ◽  
Ulf Engel
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Material Flow ◽  
Fe Simulation ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Mould Filling ◽  
Model Geometry ◽  
Functional Components

Innovative trends like increasing component functionality, the demand for automotive lightweight constructions and the economic issue to optimize existing process chains, require new ways in manufacturing. Today, the traditional sheet metal and bulk metal forming processes are often reaching their limits if closely-tolerated complex functional components with variants have to be produced. A promising approach is the direct forming of high-precision shapes starting from blanks. Thus, classic sheet metal forming operations, such as deep drawing, are combined with bulk metal forming operations like extrusion of complex variants as for example teeth. This combination of sheet and bulk metal forming operations leads to a side by side situation of different tribological conditions according to the locally varying load situations within the same forming process. This new class of forming processes is defined as sheet-bulk metal forming (SBMF). The tribological conditions in sheet-bulk metal forming processes are of major importance for the process realization, its stability and for the quality of the produced part. The objective of this paper is the investigation of material flow in SBMF in general and the attempt to improve the material flow by local adapted tribological conditions. First the material flow was analyzed by FE-simulation of a model geometry that is typical for SBMF. The investigations with FE-simulation have shown, locally adapted tribological conditions are leading to an improvement in material flow and thus to an increased mould filling. As frictional conditions are directly connected to the topography of workpiece and tool, the modification of the workpiece topography is leading to an alteration in friction values. For the modification of workpiece topography grit blasting was used. The increase in friction of grit blasted surface towards untreated surface was investigates by using the laboratory friction tests. To manufacture specimens with locally adapted topographies for forming tests a masking technique has been developed. The masks are designed after the preliminary findings determined by FE-simulation.

High-feed milling of tailored surfaces for sheet-bulk metal forming tools

2014 ◽  
Vol 9 (2) ◽  
pp. 215-223 ◽  
Author(s):  
Rouven Hense ◽  
Christoph Wels ◽  
Petra Kersting ◽  
Ulrich Vierzigmann ◽  
Maria Löffler ◽  
...  
Keyword(s):  
Metal Forming ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Tailored Surfaces ◽  
High Feed ◽  
Forming Tools

scholarly journals Laser Welding of High-strength Aluminium Alloys for the Sheet Metal Forming Process

Procedia CIRP ◽  
2014 ◽  
Vol 18 ◽  
pp. 203-208 ◽  
Author(s):  
J. Enz ◽  
S. Riekehr ◽  
V. Ventzke ◽  
N. Sotirov ◽  
N. Kashaev
Keyword(s):  
Laser Welding ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Aluminium Alloys ◽  
High Strength ◽  
Forming Process ◽  
Metal Forming Process

Numerical and Experimental Investigations of Multistage Sheet-Bulk Metal Forming Process with Compound Press Tools

2015 ◽  
Vol 651-653 ◽  
pp. 1153-1158 ◽  
Author(s):  
Bernd Arno Behrens ◽  
Anas Bouguecha ◽  
Milan Vucetic ◽  
Sven Hübner ◽  
Daniel Rosenbusch ◽  
...  
Keyword(s):  
Metal Forming ◽  
Solid Metal ◽  
Experimental Investigations ◽  
Metal Component ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Process Sequence ◽  
Metal Forming Process ◽  
Flange Forming

Sheet-bulk metal forming is a manufacturing technology, which allows to produce a solid metal component out of a flat sheet. This paper focuses on numerical and experimental investigations of a new multistage forming process with compound press tools. The complete process sequence for the production of this solid metal component consists of three forming stages, which include a total of six production techniques. The first forming stage includes deep drawing, simultaneous cutting and following wall upsetting. In the second forming stage, flange forming combined with cup bottom ironing takes place. In the last stage of the process sequence, the component is sized. To investigate and to improve process parameters such as plastic strain distribution, resulting dimensions and process forces, FEA is performed. Based on these results the developed process is designed.

An Enhanced Hybrid Springback Compensation Approach: Springback Path – Displacement Adjustment Method For Complex Shaped Products of Sheet Metal Forming

2021 ◽  
Author(s):  
Zhihui Gong ◽  
Mandeep Singh ◽  
Bohao Fang ◽  
Dongbin Wei
Keyword(s):  
Sheet Metal ◽  
Automobile Industry ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
High Strength Steels ◽  
Fem Analysis ◽  
High Strength ◽  
Design Stage ◽  
Springback Compensation ◽  
Compensation Approach

Abstract Springback compensation is critical in sheet metal forming. Advanced techniques have been adopted in the design stage of various sheet metal forming processes, e.g. stamping, some of which are for complex shaped products. However, the currently available numerical approaches are not always sufficiently accurate and reliable. To improve the accuracy of springback compensation, an enhanced hybrid springback compensation method named Springback Path – Displacement Adjustment (SP-DA) method has been developed in this study based on the well-known conventional displacement adjustment (DA) method. Its effectiveness is demonstrated using FEM analysis of low, medium and high strength steels adopted in automobile industry, in which a symmetrical model owning geometry complexity similar to an auto body panel was established. The results show this new enhanced SP-DA method is able to significantly improve the accuracy of springback compensation comparing to conventional displacement adjustment technique.

scholarly journals Material flow control in sheet-bulk metal forming processes using blasted tool surfaces

2018 ◽  
Vol 190 ◽  
pp. 13003 ◽  
Author(s):  
Marion Merklein ◽  
Maria Löffler ◽  
Daniel Gröbel ◽  
Johannes Henneberg
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Simultaneous Occurrence ◽  
Tribological Behaviour ◽  
Forming Process ◽  
Functional Elements ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Main Challenge ◽  
Functional Components

Highly-integrated and closely-tolerated functional components can be produced by sheet-bulk metal forming which is the application of bulk forming operations on sheet metals. These processes are characterized by a successive and/or simultaneous occurrence of different load conditions such as stress and strain states which reduce the geometrical accuracy of the functional elements. Thus, one main challenge within sheet-bulk metal forming is the identification of methods to control the material flow and thus to improve the product quality. One suitable approach is to control the material flow by local modifications of the tribological conditions. Within this study requirements regarding the needed adaption of the tribological conditions for a specific sheet-bulk metal forming process were defined by numerical investigations. The results reveal that a local increase of the friction leads to an improved die filling of the functional elements. Based on these results abrasive blasting as a method to modify the tool surface and thus influencing the tribological behaviour was investigated. For the determination of the tribological mechanism of blasted tool surfaces, the influence of different blasting media as well as blasting pressures on the surface integrity and the friction were determined. The correlations between surface properties and friction conditions were used to derive the mechanisms of blasted tool surfaces.

Material Characterization for Sheet-Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 1029-1034 ◽  
Author(s):  
Bernd Arno Behrens ◽  
Kathrin Voges-Schwieger ◽  
Anas Bouguecha ◽  
Jens Mielke ◽  
Milan Vucetic
Keyword(s):  
Metal Forming ◽  
Material Characterization ◽  
Cyclic Load ◽  
Material Behavior ◽  
Forming Force ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Metal Forming Process

Sheet-bulk metal forming is a novel manufacturing technology, which unites the advantages and design solutions of sheet metal and bulk metal forming. To challenge the high forming force the process is superimposed with an oscillation in the main flow of the process. The paper focuses on the characterization of the material behavior under cyclic load and the effects for the sheet bulk metal forming process.

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