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.

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.

scholarly journals Environmental Aspects Regarding The Incremental Forming Process

2015 ◽  
Vol 67 (1) ◽  
pp. 57-60
Author(s):  
Melania Tera
Keyword(s):  
Environmental Impact ◽  
Deep Drawing ◽  
Incremental Forming ◽  
Raw Materials ◽  
Mineral Resources ◽  
Point Of View ◽  
Environmental Aspects ◽  
Forming Process ◽  
Save Energy ◽  
Future Technologies

Abstract Future technologies should aim at reducing the consumption of raw materials and energy, avoid technical losses, to save energy and mineral resources, to minimize the emissions and waste, eliminate any irrational use of all resources and also to minimize the environmental impact. The paper present from environmental point of view both a classic forming process such as deep-drawing and incremental forming process. The paper gives an overview of the main environmental aspects regarding the incremental forming process.

scholarly journals Prediction and assessment of skid line formation during deep drawing of sheet metal components by using FEM simulation

2021 ◽  
Author(s):  
Patrick Cyron ◽  
Mathias Liewald ◽  
Kim-Rouven Riedmüller ◽  
Thanh-Lich Le
Keyword(s):  
Sheet Metal ◽  
Influencing Factors ◽  
Deep Drawing ◽  
Surface Defects ◽  
Sheet Material ◽  
Research Work ◽  
Fem Simulation ◽  
Subjective Perception ◽  
Forming Process ◽  
Research Activities

The subjective perception of the quality of sheet metal components mainly depends on geometric characteristics and surface structure. Additionally, particular attention must be paid in this context to avoiding surface defects such as skid lines during the sheet metal forming process. For this reason, current research activities focus on predicting such surface defects as precisely as possible in the early development stages of sheet metal components by using FEM simulation. However, the modelling approaches available today do not yet provide an adequate basis for such a numerical prediction regarding the appearance of surface defects of sheet metal components such as car body outer skin panels, especially of skid lines. Consequently, the research work reported about in this paper concentrates on the development of an empirical methodology for predicting and quantifying the formation of skid lines during deep-drawing processes by using FEM simulation. For this purpose, an experimental tool was developed to produce different skid line formations by using various process parameters and thus to investigate process-influencing factors on the example of the steel sheet material DC06. In principle, the investigations carried out showed that the punch radius and the blank holder force indeed do represent crucial influencing factors for the formation of skid lines. Finally, the results obtained were used to develop a forming simulation criterion, which allows predicting skid lines formations based on calculated strain state variables such as major strain, thinning and unbending strain.

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.

Comparison between Deep-Drawing and Incremental Forming Processes from an Environmental Point of View

2019 ◽  
Vol 957 ◽  
pp. 120-129
Author(s):  
Melania Tera ◽  
Cristina Maria Biris
Keyword(s):  
Comparative Study ◽  
Sheet Metal ◽  
Deep Drawing ◽  
Incremental Forming ◽  
Point Of View ◽  
Forming Process ◽  
Minimal Impact ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
The Comparative Study

Deep-drawing is an industrial forming process which allows the user to process large batches of sheet metals parts. One of the major drawbacks of this process is the complexity and the high cost of dies. In comparison incremental forming is a flexible process, allowing the user to obtain sheet metal parts without the need of using a die. The present paper aims to present a comparative study of the two forming processes by presenting the main advantages and drawbacks of each one. The comparative study, aimed on the industrial implementation of the incremental forming process requires a comparison of the two processes regarding the environmental impact. Thus, the results of the study will justify the selection of the incremental forming process in the case of small batches sheet metal parts in conditions of minimal impact on the environment.

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.

Core Criteria I

2018 ◽  
Author(s):  
Sanford C. Goldberg
Keyword(s):  
Cognitive Processes ◽  
Point Of View ◽  
Infinite Regress ◽  
Belief Formation ◽  
Forming Process ◽  
Epistemic Criteria ◽  
Problem Of The Criterion

Chapter 3 deals with the first issue one faces in the task of articulating the explicit epistemic criteria for belief: the problem of the criterion. It is tempting to suppose that a belief can be normatively proper from the epistemic point of view only if the believer can certify for herself the reliability of every belief-forming process on which she relied. But insisting on this quickly leads to the threat of an infinite regress. This chapter defends a foundationalist response to this problem, according to which we enjoy a default (albeit defeasible) permission to rely on certain cognitive processes in belief-formation. These are processes that satisfy what the author calls the Reliabilist Rationale. Importantly, our permissions here are social: any one of us is permitted to rely on any token process that satisfies this rationale, whether the token process resides in one’s own mind/brain or that of another epistemic subject.

Optimization of Deep Drawing Processes Using Statistical Design of Experiments

1996 ◽  
Author(s):  
Dietrich Bauer ◽  
Regine Krebs
Keyword(s):  
Mathematical Model ◽  
Analysis Of Variance ◽  
Orthogonal Array ◽  
Deep Drawing ◽  
Metal Forming ◽  
Drawing Process ◽  
Drawing Force ◽  
Forming Process ◽  
Deep Drawing Process ◽  
Metal Forming Process

Abstract For a deep drawing process some important controllable variables (factors) upon the maximum drawing force are analyzed to find a setting adjustment for these process factors that provides a very low force for the metal forming process. For this investigation an orthogonal array L18 with three-fold replication is used. To find the optimum of the process, the experimental results are analyzed in accordance with the robust-design-method according to Taguchi (Liesegang et. al., 1990). For this purpose, so-called Signal-to-Noise-ratios are calculated. The analysis of variance for this S/N-ratios leads to a mathematical model for the deep drawing process. This model allows to find the pressumed optimal settings of the investigated factors. In the following, a confirmation experiment is carried out by using these optimal settings. The maximum drawing force of the confirmation experiment does not correspond with the confidence interval, which was calculated by analysis of variance techniques. So the predicted optimum of the process does not lead to a metal forming process with very low deep drawing force. The comparison with a full factorial plan shows that there are interactions between the investigated factors. These interactions could not be discovered by the used orthogonal array. Thus the established mathematical model does not describe the relation between the factors and deep drawing force in accordance with the practical deep drawing conditions.

scholarly journals Observation of the a-C:H run-in behaviour for dry forming applications of aluminium

2018 ◽  
Vol 190 ◽  
pp. 14001
Author(s):  
Tim Abraham ◽  
Günter Bräuer ◽  
Felix Kretz ◽  
Peter Groche
Keyword(s):  
Tribological Properties ◽  
Forming Process ◽  
Premature Failure ◽  
Dry Forming ◽  
Coating Roughness ◽  
Tool Performance ◽  
Coated Tool ◽  
Tool Coatings ◽  
Strip Drawing ◽  
Amorphous Hydrogenated Carbon

Amorphous hydrogenated carbon coatings (a-C:H) are well known for their exceptional tribological properties and are established as tool coatings for numerous forming applications. However, utilized in dry forming processes of aluminium a premature failure of an a-C:H coated tool often occurs due to strong adhesive wear. In this paper the run-in behaviour of a-C:H is investigated and as a possible reason for the premature tool failure evaluated. Therefore, oscillating ball-on-disc tribometer tests and strip drawing tests, for a more realistic emulation of real forming processes, will be conducted. According to these tests, the run-in period of a-C:H coatings is characterized by a high friction value and adhesion tendency and thus is decisive for the tool performance. Based on a subsequent analysis of the coating wear, the predominating wear mechanisms during the run-in period are discussed. The intrinsic nanomater-scale a-C:H roughness is identified as a crucial factor determining the tribological properties of the run-in behaviour. By reducing the coating roughness prior to the forming process, the adhesion tendency and friction value can be reduced significantly. The results demonstrate the tribological performance of pre-treated a-C:H coatings for dry sheet metal forming of aluminium EN AW-5083.

Friction reduction in EHL contacts by surface microtexturing – tribological performance, manufacturing and tailored design

2019 ◽  
Vol 71 (8) ◽  
pp. 986-990 ◽  
Author(s):  
Stephan Tremmel ◽  
Max Marian ◽  
Michael Zahner ◽  
Sandro Wartzack ◽  
Marion Merklein
Keyword(s):  
Product Life Cycle ◽  
Structural Parameters ◽  
Surface Texturing ◽  
Friction Reduction ◽  
Forming Process ◽  
Friction Behavior ◽  
Holistic View ◽  
Content Type ◽  
Efficient Manufacturing ◽  
Tailored Design

Purpose This paper aims to derive tailor-made microtextures for elastohydrodynamically lubricated (EHL) contacts under consideration of manufacturing possibilities. Design/methodology/approach Component tests were used for the evaluation of the influence of surface texturing on the friction behavior in the cam/tappet contact. Furthermore, the manufacturing possibilities and limitations of a combined μEDM and micro-coining process and the feasibility of integration into a forming process were studied. Finally, a methodology based on transient EHL simulations and a meta-model of optimal prognosis was exemplarily used for microtexture optimization. Findings It was found that surface texturing in EHL contacts with high amount of sliding is promising. Moreover, the combination of μEDM and micro coining and the integration into established production processes allow the manufacturing of microtextures with desirable structural parameters and sufficient accuracy. Originality/value This paper gives a holistic view on surface microtexturing over several phases of the product life cycle, from the design, over efficient manufacturing to application-related testing.

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