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.

scholarly journals Investigation on blasted tool surfaces as a measure for material flow control in sheet-bulk metal forming

2019 ◽  
Vol 6 ◽  
pp. 10 ◽  
Author(s):  
Marion Merklein ◽  
Maria Löffler ◽  
Daniel Gröbel ◽  
Johannes Henneberg
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Simultaneous Occurrence ◽  
Tribological Behaviour ◽  
Bulk Metal ◽  
Geometrical Accuracy ◽  
Bulk Metal Forming ◽  
Tribological System ◽  
Local Modification ◽  
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 metal. These processes are characterized by a successive and/or simultaneous occurrence of different load conditions which reduce the geometrical accuracy of the parts. One challenge within sheet-bulk metal forming is the identification of methods to control the material flow to improve the product quality. A suitable approach is the local modification of the tribological conditions. Within this study, requirements regarding the needed adaption of the tribological system for a specific process were defined by numerical investigations. The results reveal that a local increase of the friction leads to an improved geometrical accuracy. 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. Additionally, the functional stability of a modification was investigated. Finally, the correlations between surface properties and friction conditions were used to derive the mechanisms of blasted tool surfaces.

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.

scholarly journals Material Flow Analysis for the Incremental Sheet-Bulk Gearing by Rotating Tools

2017 ◽  
Author(s):  
Sebastian Wernicke ◽  
Peter Sieczkarek ◽  
Joshua Grodotzki ◽  
Soeren Gies ◽  
Nooman Ben Khalifa ◽  
...  
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Process Time ◽  
Forming Process ◽  
Element Analysis ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Functional Components

The manufacturing of gear elements by forming offers advantages regarding the resulting mechanical properties of the functional components. One possible approach is offered by the incremental sheet-bulk metal forming of gears using a linear motion punch. This method is highly flexible in terms of shape and position of the functional elements to be produced, but inefficient from an economical point of view due to the high process time. This paper presents a new sheet-bulk gear forming process using rotating tools in order to speed up the manufacturing process of load-adapted gears. Here, different concepts with rotating tools being synchronized and non-synchronized to the workpiece are investigated to form high-strength, load-adapted gears made of bainitic steel BS600. The focus is on the analysis of the occurring material flow which is examined by means of finite element analysis and microstructural investigations to ensure the manufacture of fully functional geared components by this sheet-bulk metal forming process.

Improved Sheet Bulk Metal Forming Processes by Local Adjustment of Tribological Properties

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
H. Hetzner ◽  
J. Koch ◽  
S. Tremmel ◽  
S. Wartzack ◽  
M. Merklein
Keyword(s):  
Contact Pressure ◽  
Metal Forming ◽  
Material Flow ◽  
System Analysis ◽  
Sheet Thickness ◽  
Fe Model ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Functional Features

This paper is focused on a combined deep drawing and extrusion process dedicated to the new process class of sheet bulk metal forming (SBMF). Exemplified by the forming of gearings, combined sheet and bulk forming operations are applied to sheet metal in order to form local functional features through an intended and controlled change of the sheet thickness. For investigations on the form filling and the identification of significant influencing factors on the material flow, a FE simulation model has been built. The FE model is validated by the results of manufacturing experiments using DC04 with a thickness of 2.0 mm as blank material. Due to the fact that the workpiece is in extensive contact to the tool surface and that the pressure reaches locally up to 2500 MPa, the tribological conditions are a determining factor of the process. Thus, their influence is discussed in detail in this paper. In the first instance, different frictional zones having a distinct effect on the resulting material flow are identified and their effect on improved form filling is demonstrated. Subsequently, a more comprehensive methodology is developed to define tribological zones of forming tools. For this, a system analysis of the digital mock-up of the forming process is performed. Besides friction, other relevant aspects of forming tool tribology like contact pressure, sliding velocity, and surface magnification are considered. The gathered information is employed to partition the tools into tribological zones. This is done by systematically intersecting and re-merging zones identified for each of the criterion. The so-called load-scanning test allows the investigation of the friction coefficient in dependence of the contact pressure and possible loading limits of tribological pairings. It provides an appropriate tribological model test to evaluate tribological measures like coatings, surface textures and lubricants with respect to their targeted application in particular zones. The obtained results can be employed in the layout of further forming processes to reach the desired process behavior. This can be, for example, an improved form filling, less abrasive wear and adhesive damage or lower forming forces, respectively tool load for an improved durability of the die.

Analysis of Effectiveness of Locally Adapted Tribological Conditions for Improving Product Quality in Sheet-Bulk Metal Forming

2015 ◽  
Vol 794 ◽  
pp. 81-88 ◽  
Author(s):  
Maria Löffler ◽  
Daniel Groebel ◽  
Ulf Engel ◽  
Kolja Andreas ◽  
Marion Merklein
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Operating Time ◽  
Wear Behaviour ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Geometrical Features ◽  
Tailored Surfaces ◽  
Economic Developments ◽  
Functional Components

Due to current ecological and economic developments there is a growing demand for functional components with complex and closely tolerated geometrical features. Conventional sheet and bulk metal forming operations leads to products which are often limited in their geometrical and functional variety. A promising approach is the process-class sheet-bulk metal forming (SBMF). SBMF is characterised by the application of bulk and sheet forming operations on sheet metals [1]. This combination leads to locally and temporally varying load conditions regarding stress as well as strain states. In order to get high quality parts, controlling the material flow is of major importance. Modified Surfaces, so-called tailored surfaces represent an innovative approach to control the material flow. The objective of the current study is the experimental investigation of the effectiveness of locally adapted tribological conditions using workpiece-and tool-sided tailored surfaces within SBMF processes. The study has shown that the local adaption of workpiece and tool surface increased the heights of functional elements. Thus, using locally adapted tribological conditions leads to an improvement of the quality of the produced gearing components. In a further step the influence of surface modifications on the surface properties of the manufactured components are analysed. Additionally, investigations regarding the wear behaviour of tool-sided surface adaptions lead to the assumption, that the effectiveness of tailored surfaces is reduced during the operating time of the tools.

Sheet-Bulk Metal Forming of Symmetric and Asymmetric Parts

2013 ◽  
Vol 769 ◽  
pp. 229-236 ◽  
Author(s):  
Valerian Salfeld ◽  
Richard Krimm ◽  
Sven Hübner ◽  
Thorsten Matthias ◽  
Milan Vucetic
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Three Dimensional ◽  
Positive Influence ◽  
Sheet Metals ◽  
Functional Elements ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
New Machine

The unique process of sheet-bulk metal forming (SBMF) represents a combination of sheet and bulk metal forming by inducing a three-dimensional material flow in sheet metals in a single forming stage. Within this paper two different applications of sheet-bulk metal forming are demonstrated. Hereby two different combined drawing and upsetting processes to realize parts with symmetrically and asymmetrically arranged functional elements are analysed. Finally, this contribution introduces a new machine technique which provides an improvement of the working accuracy of a forming machine and thus has a positive influence on the parts quality. The idea is to use electromagnetic ram guidance to counteract the displacement of the ram due to horizontal forming forces while forming of asymmetric parts.

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 Investigation on tailored blanks in a full forward extrusion process of sheet-bulk metal forming

2021 ◽  
Author(s):  
Manuel Reck ◽  
Marion Merklein
Keyword(s):  
Heat Treatment ◽  
Metal Forming ◽  
Material Flow ◽  
Sheet Thickness ◽  
Extrusion Process ◽  
Functional Elements ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Forward Extrusion ◽  
Tailored Blanks

Due to the ongoing technological development, the demand for geometrically complicated high performance parts with great functional density is increasing. Often, the use of sheet metal is a beneficial approach in manufacturing technology to meet the requirements on components regarding material strength and lightweight construction goals. The forming of therefore required complex sheet metal part geometries with integrated functional elements cause the need for a three dimensional material flow. Sheet-bulk metal forming, characterized by the application of bulk forming operations on sheet metals, is a suitable approach to produce such components. A challenge is the material flow control, resulting in an insufficient die filling of the functional elements. The use of tailored blanks with a defined sheet thickness distribution is an auspicious approach to face this challenge in subsequent forming processes. In the presented work, semi-finished products with a continuous thickness profile manufactured by orbital forming are applied in a full forward extrusion process. By an additional implementation of a heat treatment, the tailored blanks undergo a recrystallization process that causes a softening of the strain hardened material. In this paper, the potential of a heat treatment in the process class of sheet-bulk metal forming is shown by characterizing the geometrical and mechanical properties of the functional components by applying the mild deep drawing steel DC04 with an initial sheet thickness of t0 = 2.0 mm.

Sign in / Sign up

Export Citation Format

Share Document