Load path modelling in single-step deep drawing of rotationally symmetric cups

Within deep drawing processes, welding represents an innovative approach to optimising the branched process chains which entail uneconomic process steps in production and transport lines. Previous applications of thermal joining processes in presses required a downstream process step for joining standardised functional elements such as nuts. Within the scope of this publication, a weldable tool system is presented which offers the possibility of welding a deep drawing component to an automatically added non-standardised holder in a single-step deep drawing process without additional dwell time in the bottom dead point. In order to realise this innovative tool system, the interdependencies of deep drawing and projection welding are considered to enable a splash-free welding on flat and curved component areas, such as the rounding of a punch edge. Based on experimental research a special concept for the tool kinematics of welding electronics is drawn up which is based on press kinematics. In addition, this article also deals with electric insulation and the forming forces which have an impact on the welding electrodes integrated into the active surface of the forming tool. Thus, the joining process becomes independent from the type of press.

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Hydromechanical Deep Drawing of Funerary Vases: A Suitable Alternative to the Traditional Forming Processes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.344.485 ◽

2007 ◽

Vol 344 ◽

pp. 485-492 ◽

Cited By ~ 2

Author(s):

Paolo Bortot ◽

Elisabetta Ceretti ◽

Antonio Fiorentino ◽

Claudio Giardini

Keyword(s):

Deep Drawing ◽

Experimental Tests ◽

Single Step ◽

Drawing Process ◽

Production Environment ◽

Suitable Alternative ◽

Hydromechanical Deep Drawing ◽

Casting Technology ◽

Fe Simulations ◽

Volume Production

In the present paper a feasibility study of a funerary vase, made of stainless steel, using the Hydromechanical Deep Drawing process, is presented. The component is currently made of bronze and manufactured by die casting technology in a low volume production environment. To investigate the part feasibility, several FE simulations were implemented using the Aquadraw tool of the explicit FE code Pam Stamp 2G 2005®. The FE simulations showed that HDD process can produce the part in one single step without the requirement of finishing operations such as painting or polishing. Furthermore experimental tests were conducted and the first prototypes were successfully produced.

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Improved analytical model for deep drawing processes of rotationally symmetric cups

10.1063/1.1766632 ◽

2004 ◽

Cited By ~ 3

Author(s):

E. Doege

Keyword(s):

Analytical Model ◽

Deep Drawing ◽

Rotationally Symmetric

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Influence of pass reduction in cold rolling on damage evolution in deep drawing of rotationally symmetric cups

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1157/1/012050 ◽

2021 ◽

Vol 1157 (1) ◽

pp. 012050

Author(s):

M Nick ◽

C Liebsch ◽

M Müller ◽

IF Weiser ◽

G Hirt ◽

...

Keyword(s):

Cold Rolling ◽

Deep Drawing ◽

Damage Evolution ◽

Rotationally Symmetric

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Practical Correction of Three Fold Astigmatism in the Philips CM TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164556 ◽

1996 ◽

Vol 54 ◽

pp. 418-419

Author(s):

Arno J. Bleeker ◽

Mark H.F. Overwijk ◽

Max T. Otten

Keyword(s):

Optical Properties ◽

Phase Contrast ◽

The Other ◽

Objective Lens ◽

Symmetric Part ◽

A Posteriori ◽

Contrast Transfer Function ◽

High Brightness ◽

Rotationally Symmetric ◽

Brightness Field

With the improvement of the optical properties of the modern TEM objective lenses the point resolution is pushed beyond 0.2 nm. The objective lens of the CM300 UltraTwin combines a Cs of 0. 65 mm with a Cc of 1.4 mm. At 300 kV this results in a point resolution of 0.17 nm. Together with a high-brightness field-emission gun with an energy spread of 0.8 eV the information limit is pushed down to 0.1 nm. The rotationally symmetric part of the phase contrast transfer function (pctf), whose first zero at Scherzer focus determines the point resolution, is mainly determined by the Cs and defocus. Apart from the rotationally symmetric part there is also the non-rotationally symmetric part of the pctf. Here the main contributors are not only two-fold astigmatism and beam tilt but also three-fold astigmatism. The two-fold astigmatism together with the beam tilt can be corrected in a straight-forward way using the coma-free alignment and the objective stigmator. However, this only works well when the coefficient of three-fold astigmatism is negligible compared to the other aberration coefficients. Unfortunately this is not generally the case with the modern high-resolution objective lenses. Measurements done at a CM300 SuperTwin FEG showed a three fold-astigmatism of 1100 nm which is consistent with measurements done by others. A three-fold astigmatism of 1000 nm already sinificantly influences the image at a spatial frequency corresponding to 0.2 nm which is even above the point resolution of the objective lens. In principle it is possible to correct for the three-fold astigmatism a posteriori when through-focus series are taken or when off-axis holography is employed. This is, however not possible for single images. The only possibility is then to correct for the three-fold astigmatism in the microscope by the addition of a hexapole corrector near the objective lens.

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New Feasible Concepts of Aberration Correction for Realizing High-Resolution Electron Microscopes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100179762 ◽

1990 ◽

Vol 48 (1) ◽

pp. 202-203

Author(s):

H. Rose

Keyword(s):

Spherical Aberration ◽

Wave Length ◽

Electron Wave ◽

Optical Lens ◽

Resolution Electron ◽

Rotationally Symmetric ◽

Electron Microscopes ◽

The Cost ◽

Imaging Performance ◽

Acceleration Voltage

The imaging performance of the light optical lens systems has reached such a degree of perfection that nowadays numerical apertures of about 1 can be utilized. Compared to this state of development the objective lenses of electron microscopes are rather poor allowing at most usable apertures somewhat smaller than 10-2 . This severe shortcoming is due to the unavoidable axial chromatic and spherical aberration of rotationally symmetric electron lenses employed so far in all electron microscopes.The resolution of such electron microscopes can only be improved by increasing the accelerating voltage which shortens the electron wave length. Unfortunately, this procedure is rather ineffective because the achievable gain in resolution is only proportional to λ1/4 for a fixed magnetic field strength determined by the magnetic saturation of the pole pieces. Moreover, increasing the acceleration voltage results in deleterious knock-on processes and in extreme difficulties to stabilize the high voltage. Last not least the cost increase exponentially with voltage.

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