An innovative process combination of additive manufacturing and sheet bulk metal forming for manufacturing a functional hybrid part

2021 ◽  
Vol 291 ◽  
pp. 117032
Author(s):  
Marion Merklein ◽  
Robert Schulte ◽  
Thomas Papke
Keyword(s):  
Additive Manufacturing ◽  
Metal Forming ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Innovative Process ◽  
Process Combination

Locally Adapted Tribological Conditions as a Method for Influencing the Material Flow in Sheet-Bulk Metal Forming Processes

2015 ◽  
Vol 639 ◽  
pp. 267-274 ◽  
Author(s):  
Maria Loeffler ◽  
Thomas Schneider ◽  
Ulrich Vierzigmann ◽  
Ulf Engel ◽  
Marion Merklein
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Bulk Forming ◽  
Mould Filling ◽  
Stage Process ◽  
Functional Components ◽  
Process Combination ◽  
Abrasive Blasting

Due to ecological and economic challenges there is a growing demand for lightweight construction by using closely-tolerated complex functional components with variants. Conventional sheet and bulk metal forming operations are often improvident in producing such parts. A promising approach is the process-class “sheet-bulk metal forming” (SBMF). Within SBMF bulk forming operations are applied to sheet metals, often in combination with sheet forming operations [1]. This leads to a significant gradient in load conditions regarding stress and strain states and causes locally varying tribological conditions. Thus, the investigation of the tribological conditions and the provision of suited tribological systems are essential for the successful application of SBMF processes. The objective of the current study is the experimental investigation of the applicability of tribological adaptions by local abrasive blasting on a single-stage process combination of deep drawing and upsetting to produce a component with an external gearing. The manipulation of the local tribological conditions by the use of abrasive blasting leads to a better control of the material flow and in consequence to an improved quality of the components in terms of higher mould filling and cup heights, and a reduced thickening of the sheet in the area of the cup bottom.

scholarly journals Bulk Metal Forming of Additively Manufactured Elements

2018 ◽  
Vol 190 ◽  
pp. 03002 ◽  
Author(s):  
Thomas Papke ◽  
Daniel Junker ◽  
Michael Schmidt ◽  
Tobias Kolb ◽  
Marion Merklein
Keyword(s):  
Additive Manufacturing ◽  
Material Properties ◽  
Metal Forming ◽  
Machining Process ◽  
Grain Structure ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Geometric Precision ◽  
Forming Behaviour

Current trends in the industry go towards individualised parts in high volume production. Facing the high amount of different parts, efficient processes with a high flexibility are necessary. Within this context, laser-based additive manufacturing of metal parts become more important. These processes enable the production of individual geometries using a variety of metal materials. However, main challenges of this technology are rough surfaces, limited geometric precision and varying material properties. Therefore machining after the additive manufacturing process is a common approach for improving surface quality and geometric accuracy. However, the machining process affects the grain structure at the edges of the part. Using forming instead leads to a deformation of the grains but does not create new interfaces. Furthermore, the material properties can be improved due to work hardening and fibre flow. Within this work, a bulk metal forming process of an additively manufactured element of stainless steel 316L will be analysed. The aim of the investigation is a fundamental understanding of the forming behaviour and the material flow of an additively built metal part compared to the conventionally manufactured material. Therefore mechanical properties of both materials will be identified by upsetting tests. Additionally, fibre flow and Vickers hardness before and after the forming operation are analysed. It is detected that the forming behaviour of the additively manufactured material is strongly influenced by the layer-wise building process.

scholarly journals Development of a numerical compensation framework for geometrical deviations in bulk metal forming exploiting a surrogate model and computed compatible stresses

2021 ◽  
Author(s):  
Lorenzo Scandola ◽  
Christoph Büdenbender ◽  
Michael Till ◽  
Daniel Maier ◽  
Michael Ott ◽  
...  
Keyword(s):  
Finite Element ◽  
Surrogate Model ◽  
Metal Forming ◽  
Computer Aided Design ◽  
Transition Process ◽  
Reference Points ◽  
Compensation Method ◽  
Tool Geometry ◽  
Bulk Metal ◽  
Bulk Metal Forming

AbstractThe optimal design of the tools in bulk metal forming is a crucial task in the early design phase and greatly affects the final accuracy of the parts. The process of tool geometry assessment is resource- and time-consuming, as it consists of experience-based procedures. In this paper, a compensation method is developed with the aim to reduce geometrical deviations in hot forged parts. In order to simplify the transition process between the discrete finite-element (FE) mesh and the computer-aided-design (CAD) geometry, a strategy featuring an equivalent surrogate model is proposed. The deviations are evaluated on a reduced set of reference points on the nominal geometry and transferred to the FE nodes. The compensation approach represents a modification of the displacement-compatible spring-forward method (DC-SF), which consists of two elastic FE analyses. The compatible stress originating the deviations is estimated and subsequently applied to the original nominal geometry. After stress relaxation, an updated nominal geometry of the part is obtained, whose surfaces represent the compensated tools. The compensation method is verified by means of finite element simulations and the robustness of the algorithm is demonstrated with an additional test geometry. Finally, the compensation strategy is validated experimentally.

Fundamental investigations on the material flow at combined sheet and bulk metal forming processes

CIRP Annals ◽  
2011 ◽  
Vol 60 (1) ◽  
pp. 283-286 ◽  
Author(s):  
M. Merklein ◽  
J. Koch ◽  
S. Opel ◽  
T. Schneider
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Bulk Metal ◽  
Bulk Metal Forming

Amorphous Carbon Coatings for Locally Adjusted Tribological Properties in Sheet Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 969-974 ◽  
Author(s):  
Harald Hetzner ◽  
Stephan Tremmel ◽  
Sandro Wartzack
Keyword(s):  
Amorphous Carbon ◽  
Tribological Properties ◽  
Metal Forming ◽  
Friction And Wear ◽  
Wear Properties ◽  
Carbon Coatings ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Friction And Wear Properties ◽  
Amorphous Carbon Coatings

In sheet bulk metal forming, locally adapted friction properties of the contact tool/workpiece are an appropriate means for the targeted enhancement of the material flow, enabling an improved form filling and lowered forming forces. However, the implementation of desirable friction conditions is not trivial. And further, friction is inseparably linked to wear and damage of the contacting surfaces. This calls for a methodological approach in order to consider tribology as a whole already in the early phases of process layout, so that tribological measures which allow fulfilling the requirements concerning local friction and wear properties of the tool surfaces, can already be selected during the conceptual design of the forming tools. Thin tribological coatings are an effective way of improving the friction and wear properties of functional surfaces. Metal-modified amorphous carbon coatings, which are still rather new to the field of metal forming, allow tackling friction and wear simultaneously. Unlike many other types of amorphous carbon, they have the mechanical toughness to be used in sheet bulk metal forming, and at the same time their friction properties can be varied over wide ranges by proper choice of the deposition parameters. Based on concrete research results, the mechanical, structural and special tribological properties of tungsten-modified hydrogenated amorphous carbon coatings (a-C:H:W) are presented and discussed against the background of the tribological requirements of a typical sheet bulk metal forming process.

scholarly journals Development of a Constitutive Model for Friction in Bulk Metal Forming

Lubricants ◽  
2018 ◽  
Vol 6 (2) ◽  
pp. 42 ◽  
Author(s):  
Marco Lüchinger ◽  
Igor Velkavrh ◽  
Kerstin Kern ◽  
Michael Baumgartner ◽  
Stefan Klien ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Metal Forming ◽  
Bulk Metal ◽  
Bulk Metal Forming

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.

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