Wear Analysis of Tool Surfaces Structured by Machine Hammer Peening for Foil-Free Forming of Stainless Steel

2014 ◽  
Vol 1018 ◽  
pp. 317-324 ◽  
Author(s):  
Fritz Klocke ◽  
Daniel Trauth ◽  
Michael Terhorst ◽  
Patrick Mattfeld
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Contact Area ◽  
Deep Drawing ◽  
Surface Structures ◽  
Main Concern ◽  
Forming Process ◽  
Machine Hammer Peening ◽  
Strip Drawing ◽  
Hammer Peening

Increasing demands concerning the performance of tribological systems for metal forming due to ecological restrictions or technologically increased process loads require the development of innovative tribological systems, especially in forming of stainless steel. It could be shown in preliminary work that surface structures on deep drawing tools manufactured by the incremental forming process machine hammer peening have the potential to reduce friction in strip drawing test by about 58 % in comparison with a ground reference surface. This is explained by the effect of lubricant pockets and a reduced true contact area in the interacting zone. However, due to the effect of a reduced contact area, the wear resistance of these surface structures is of main concern for the effectiveness of their application in deep drawing. Therefore, in this work strip drawing tests are performed over a minimum of 500 repetitions for the evaluation of friction characteristics. Additionally, the coating of the surface structures is investigated to improve the wear resistance of the structures.

2D-CFD Analysis of the Fluid Pressure and Velocity Distribution of Experimentally Machine Hammer Peened Surface Structures in Hydrodynamic Applications

2015 ◽  
Vol 794 ◽  
pp. 174-181
Author(s):  
Daniel Trauth ◽  
Michael Terhorst ◽  
Patrick Mattfeld ◽  
Fritz Klocke
Keyword(s):  
Velocity Distribution ◽  
Deep Drawing ◽  
Fluid Dynamic ◽  
Fluid Pressure ◽  
Surface Structures ◽  
Surface Finishing ◽  
Forming Process ◽  
Machine Hammer Peening ◽  
Hydrodynamic Effects ◽  
Hammer Peening

Machine hammer peening is an incremental forming process for high frequency surface finishing of technical components. Recently, machine hammer peening has attracted automotive industry’s attention for the surface finishing and structuring of deep drawing tools. Deep drawing tools surface structured by machine hammer peening are characterized by beneficial friction and wear characteristics in lubricated sliding contacts. However, the physics of hydrodynamic effects in machine hammer peened structures is yet insufficiently researched. Therefore, this work investigates the hydrodynamic effects in surface structures generated by machine hammer peening using a two-dimensional computational fluid dynamic analysis. The effects of structure geometry, structure arrangement and selected sliding parameters on the hydrodynamic fluid pressure and velocity distribution within the structures are analysed. It was observed, that the sliding direction and the structure arrangement have a significant influence on the hydrodynamic fluid pressure maximum.

Physicochemical Analysis of Machine Hammer Peened Surface Structures for Deep Drawing: Determination of the Work of Adhesion and Spreading Pressure of Lubrication to Surface Structure

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
D. Trauth ◽  
F. Klocke ◽  
M. Terhorst ◽  
P. Mattfeld
Keyword(s):  
Deep Drawing ◽  
Research Work ◽  
Physicochemical Analysis ◽  
Point Of View ◽  
Friction Reduction ◽  
Surface Structures ◽  
Work Of Adhesion ◽  
Forming Process ◽  
Spreading Pressure ◽  
Strip Drawing

Increasing demands concerning the performance of tribological systems for metal forming due to ecological restrictions or increased process loads demand the development of innovative tribological solutions. In preliminary works, it could be shown that surface structures on deep drawing tools manufactured by the incremental forming process machine hammer peening (MHP) have the potential to reduce friction. The friction reduction can be observed in strip drawing when comparing different surface structures against a state-of-the-art reference. A subsequently conducted wear analysis showed an adhesive wear on the structures. This leads to the conclusion that the lubricant film breaks due to increased contact pressures. In order to optimize the wetting of the lubricant and to avoid film break-ups, the molecular interactions in terms of the work of adhesion and spreading pressure between lubricant and MHP tool surfaces are investigated from a physicochemical point of view in this research work. The investigation approach is based on the use of the drop shape analysis.

Influence of Machine Hammer Peening on the Tribology of Sheet Forming

2014 ◽  
Vol 966-967 ◽  
pp. 397-405 ◽  
Author(s):  
Matthias Oechsner ◽  
Johannes Wied ◽  
Johannes Stock
Keyword(s):  
Tool Path ◽  
Flow Behavior ◽  
Wave Theory ◽  
Surface Structures ◽  
Forming Process ◽  
Machine Hammer Peening ◽  
Metal Forming Process ◽  
Drawing Dies ◽  
Hammer Peening ◽  
Suitable Process

The recently developed machine hammer peening process is used at the die shop of the Mercedes-Benz plant in Sindelfingen in order to replace manual surface finish of deep drawing dies. The goal of the process is surface roughness reduction after milling to ensure the tribological properties, which are necessary for the sheet metal forming process. Using machine hammer peening it is also possible to create defined surface structures that may be employed to influence local friction conditions and therewith overcome current limitations of the forming process. To take advantage of the surface structuring capabilities it is necessary to understand how to create defined surface structures using machine hammer peening and how the created structures affect friction and material flow behavior. In this work an approach is presented to describe the interaction of milling and machine hammer peening parameters on the created topography by wave theory. Especially the influence of tool path parameters of milling and consecutive machine hammer peening is investigated. The results, which are calculated using wave theory, are verified by FEM simulations and real experiments. In addition, suitable process parameters for machine hammer peening are derived from the obtained results, as they are used at the Mercedes-Benz die shop today.

Enhanced Sliding Wear Resistance of Technical Alloys by Hard Particle Reinforcement Using Machine Hammer Peening

2016 ◽  
Vol 60 (3) ◽  
pp. 479-789 ◽  
Author(s):  
Manel Rodríguez Ripoll ◽  
Franz Heindl ◽  
Christoph Lechner ◽  
Vladimir Totolin ◽  
Martin Jech ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Hard Particle ◽  
Particle Reinforcement ◽  
Machine Hammer Peening ◽  
Hammer Peening

Deep Drawing of One-Sided, Stiffness Increasing Sheet Metal Composites

2016 ◽  
Vol 716 ◽  
pp. 879-890
Author(s):  
Dennis Hofmann ◽  
Mathias Liewald
Keyword(s):  
Sheet Metal ◽  
Deep Drawing ◽  
Global Optimum ◽  
Main Concern ◽  
Forming Process ◽  
Metal Composites ◽  
Forming Characteristics ◽  
Bead Height ◽  
Stability And Accuracy ◽  
Stiffness And Damping

Hybrid sheet metal composites do show advantages compared to monolithic materials when strength, stiffness, and damping characteristics are set to a global optimum. Even though the mechanical properties of hybrid sheet metal composites have been improved in recent years, the application of such hybrid materials in the automotive industry is not well-established due to insufficient knowledge about their forming characteristics (e.g. in deep drawing process). Stiffness increasing composites consist of two metal sheets and a viscoelastic damping layer in-between: the outer sheet reveals stamped beads which increases stiffness of composite while the inner sheet serves as cover sheet. This paper deals with challenges of formability of stiffness increasing composites in industrial deep-drawing processes. The main concern is dimensional stability and accuracy of those layered materials after finishing the forming process. In order to ensure accuracy of formed parts, a methodology was developed for increased quality of sheet metal composites. Depending on the drawing limit ratios and blankholder forces, which evaluate the drawability of component in general, the drawing limit ratio is influenced for profound or insufficient residual bead heights and widths. Besides insufficient bead height, which causes a reduction in moment of inertia, inner marks on the visible outer sheet hamper a broad application in practical use. Finally, paper provides detailed recipies for manufacturing and tool layout for deep drawing objectives of such composite material.

Coating of Deep Rolled and Hammer Peened Deep Drawing Tools

2013 ◽  
Vol 769 ◽  
pp. 245-252 ◽  
Author(s):  
Manuel Steitz ◽  
Kai Weigel ◽  
Martin Weber ◽  
Jan Scheil ◽  
Clemens Müller
Keyword(s):  
Deep Drawing ◽  
Wear Behavior ◽  
High Strength Steels ◽  
High Strength ◽  
Coated Tools ◽  
Wear Protection ◽  
Drawing Test ◽  
Strip Drawing ◽  
Hammer Peening ◽  
Die And Mold

Mechanical surface treatments like machine hammer peening and deep rolling can substitute an essential part of the manual polishing time in the conventional process chain of die and mold production. However, the increasing use of high strength steels in the automotive industry and the associated wear of deep drawing tools require further wear-protection methods. In this context it is still unknown if hammer peened and deep rolled surfaces can ensure a sufficient adhesive strength of a coating. Therefore, in the present work different coatings are applied on hammer peened and deep rolled surfaces. Finally, the wear behavior is examined in the strip drawing test. The evaluation of the experimental results proves the potential for an industrial application of the mechanically treated and coated tools.

scholarly journals Surface Integrity of AISI 52100 Bearing Steel after Robot-Based Machine Hammer Peening

2020 ◽  
Vol 4 (2) ◽  
pp. 61
Author(s):  
Robby Mannens ◽  
Lars Uhlmann ◽  
Felix Lambers ◽  
Andreas Feuerhack ◽  
Thomas Bergs
Keyword(s):  
Surface Layer ◽  
Surface Integrity ◽  
Bearing Steel ◽  
Forming Process ◽  
Premature Failure ◽  
Machine Hammer Peening ◽  
Aisi 52100 ◽  
Aisi 52100 Steel ◽  
Hardness Increase ◽  
Hammer Peening

AISI 52100 steel is often used as material for highly loaded rolling bearings in machine tools. An improved surface integrity, which can be achieved by means of mechanical surface layer finishing, can avoid premature failure. One of these finishing processes is machine hammer peening (MHP) which is a high-frequency incremental forming process and mostly used on machining centers. However, the influence of robot-guided MHP processing on the surface integrity of AISI 52100 steel is still unknown. Therefore, the objective of this work is to investigate experimentally the robot-based influences during MHP processing and the resulting surface integrity of unhardened AISI 52100 steel. The results show that the axial and lateral deviations of the robot due to process vibrations are in the lower µm range, thus enabling stable and reproducible MHP processing. By selecting suitable MHP process parameters and thus defined contact energies, even ground surfaces can be further smoothed and a hardness increase of 75% in the energy range considered can be achieved. In addition, compressive residual stress maxima of 950 MPa below the surface and a grain size reduction to a surface layer depth of 150 µm can be realized.

scholarly journals Computer-Assisted Design of Sheet Metal Component Formed from Stainless Steel

2018 ◽  
Vol 65 (2) ◽  
pp. 71-78
Author(s):  
Tomaž Pepelnjak ◽  
Tomaž Bren ◽  
Bojan Železnik ◽  
Mitja Kuštra
Keyword(s):  
Stainless Steel ◽  
Deep Drawing ◽  
Research Work ◽  
Computer Assisted ◽  
Digital Environment ◽  
Metal Component ◽  
Forming Process ◽  
Computer Assisted Design ◽  
Set Up ◽  
Sheet Metal Component

Abstract The development of the product from stainless steel, which is produced for the client in large series, is presented. Technological optimisation was mainly focussed on the design of the deep drawing process in a single operation, which proved to be technologically unstable and therefore unfeasible for the prescribed shape of the product. Testing of prototype products showed unacceptable wrinkling due to the cone-shaped geometry of the workpiece. For this purpose, the research work was oriented towards technological optimisation of forming operations and set-up of proper phase plan in order to eliminate the wrinkling of the material. Testing of several different materials of the same quality was performed to determine the appropriate input parameters used for digital analyses. The analyses were focussed towards the set-up of optimal forming process and appropriate geometry of the corresponding tool, which allowed deep drawing of the workpiece without tearing and/or wrinkling of the material. Performed analyses of the forming process in the digital environment were tested with experiments, which showed a good correlation between the results of both development concepts.

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