scholarly journals Material Flow in Infeed Rotary Swaging of Tubes

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 58
Author(s):  
Yang Liu ◽  
Jing Liu ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Wall Thickness ◽  
Material Flow ◽  
Outer Diameter ◽  
Forming Process ◽  
Hardening Material ◽  
Rotary Swaging ◽  
Metal Forming Process ◽  
Combined Hardening ◽  
Lubrication Conditions ◽  
Insight Into

Rotary swaging is an incremental metal forming process widely used to reduce the cross–section of parts. For tubular parts, the final wall thickness also changes during the process. The lubricant condition is a factor, which affects these geometry changes. Beneath the change of the geometry, the complex material flow during the process determines the final geometry and the mechanical properties. Therefore, with a thorough insight into the material flow, it could be understood how to control it in order to achieve desired properties. Producing tubes with uniform outer diameter and changing inner profiles is an application of this method. Furthermore, applying this method, different local cold hardening could be achieved by different total strain. In this study, the dependency of the material flow on the lubrication conditions was investigated. Simulations with combined hardening material models were verified by the change of the wall thickness of tubes. It was found that friction condition significantly influences the back shifting of the workpiece and the elongation caused by each stroke. Results from simulations and experiments showed that a certain lubricant condition leads to the highest axial elongation of the workpiece.

scholarly journals High productivity micro rotary swaging

2018 ◽  
Vol 190 ◽  
pp. 15002 ◽  
Author(s):  
Eric Moumi ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Material Flow ◽  
Process Variations ◽  
Main Process ◽  
Forming Process ◽  
Workpiece Material ◽  
High Productivity ◽  
Rotary Swaging ◽  
Micro Parts ◽  
Intensive Investigation ◽  
Clamping Device

Rotary swaging is an incremental forming process with two main process variations plunge and infeed rotary swaging. With plunge rotary swaging, the diameter is reduced within a limited section whereas the infeed rotary swaging enables a diameter reduction over the entire workpiece length. The process is now subject to intensive investigation for manufacturing of micro parts. By increasing the process speed, failures occur particularly due to inappropriate material flow. In plunge rotary swaging, the workpiece material can flow radially into the gap between the dies and thus the workpiece quality suffers. In infeed rotary swaging the workpiece material flows against the feeding direction and can provoke bending or braking of the workpiece. Therefore, additional measures to control both the radial and the axial material flow to enable high productivity micro rotary swaging are investigated. The radial material flow during plunge rotary swaging can be controlled by elastic intermediate elements that enable an increase of productivity by factor three. A spring-loaded clamping device that enables an increase of the productivity by factor four can temporarily buffer the axial material flow in infeed rotary swaging against the feeding direction.

scholarly journals Axial and Radial Material Flow Analysis in Infeed Rotary Swaging of Tubes

2018 ◽  
Vol 190 ◽  
pp. 04003 ◽  
Author(s):  
Yang Liu ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Wall Thickness ◽  
Material Flow ◽  
Flow Direction ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Relative Wall Thickness ◽  
Cold Forming ◽  
Rotary Swaging ◽  
Fundamental Insight ◽  
Actual Ratio

In rotary swaging – an incremental cold forming production technique to reduce the diameter of axisymmetric parts – the material flow can be assumed to be predominantly axial and radial. The actual ratio of this axial and radial flow influences the mechanical properties and especially in tube forming the final geometry. It is known that during mandrel free infeed rotary swaging of tubes the wall thickness changes. The change is depending on the process parameters like incremental and cumulated strain. Hence, the ratio of axial and radial material flow changes. Consequently, the analysis of the wall thickness of rotary swaged tubes enables fundamental insight how to control the material flow direction. In this study, the infeed rotary swaging process of steel tubes with different wall thicknesses from 3 mm to 7 mm and rods were investigated with FEM under two feeding velocities. The axial and radial material flow and the resulting geometry were studied by the relative wall thickness. It could be seen that the relative wall thickness was affected by the feeding velocity as well as the initial wall thickness. The findings of the simulation were validated by rotary swaging experiments.

Effective Forming Processes of Hub Forging from Aluminum Alloy AlCu2SiMn

2013 ◽  
Vol 773-774 ◽  
pp. 115-118
Author(s):  
Andrzej Gontarz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Metal Forming ◽  
Material Flow ◽  
Theoretical Research ◽  
Material Consumption ◽  
Forming Process ◽  
Metal Forming Process ◽  
Large Material

This paper presents results of theoretical and experimental research works on metal forming process of a hub. A typical technology of forging on hammer of this part with flash was discussed. Two new processes of a hub forging were proposed, characterized by large material savings in comparison with typical technology. The first process is based on forming without flash of a forging with axial cavity. The second one is connected with forming of forging from pipe billet. The realization of these processes is possible at the application of a press with three movable working tools. Theoretical research works were done on the basis of simulations by means of finite element method. Simulations were made mainly in order to determine kinematics of material flow in forging processes and precision of shape and dimensions of obtained products. The first of the proposed processes was experimentally verified and a product of good quality was obtained. Material consumption of the analyzed processes and other factors acting on their effectiveness were also compared.

Modeling of the Friction Behavior in Metal Forming Process Considering Material Hardening and Junction Growth

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Mengyun Mao ◽  
Linfa Peng ◽  
Peiyun Yi ◽  
Xinmin Lai
Keyword(s):  
Metal Forming ◽  
Friction Stress ◽  
Friction Model ◽  
Real Contact Area ◽  
Forming Process ◽  
Friction Behavior ◽  
Hardening Material ◽  
Simulation And Optimization ◽  
Metal Forming Process ◽  
Nonlinear Hardening

In various plastic forming processes of metals, friction has been revealed to play an important role in the determination of the material flow, fracture, and surface quality. The precise description of friction behavior is thus a critical issue for the accurate prediction and analysis of these formability indicators. Generally, the friction behavior is inevitably affected by material hardening and junction growth. However, few of the previous models have taken both of them into consideration, especially for the nonlinear hardening materials. In this study, the classical contact model was modified to include the power-law hardening material, and the general friction law combined with Tabor's equation was employed to estimate the friction stress with the junction growth of asperities. An asperity-based friction model for rough surfaces in metal forming process was then obtained by summarizing the normal and tangential stresses of all the asperities on the surface using Greenwood and Williamson (GW) method. The model was validated by comparing to the finite element (FE) results and the experimental results. And its comparison with Kogut and Etsion (KE) model and Cohen's model revealed a wider range of application for the present model. It was also found to be able to predict the friction coefficient and the real contact area of nonlinear hardening materials under various contact conditions. This work is helpful to understand the friction behavior and further guide the simulation and optimization of forming processes.

Effective Forming Processes of Hub Forging from Aluminum Alloy AlCu2SiMn

2013 ◽  
Vol 572 ◽  
pp. 265-268
Author(s):  
Andrzej Gontarz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Metal Forming ◽  
Material Flow ◽  
Theoretical Research ◽  
Material Consumption ◽  
Forming Process ◽  
Metal Forming Process ◽  
Large Material

This paper presents results of theoretical and experimental research works on metal forming process of a hub. A typical technology of forging on hammer of this part with flash was discussed. Two new processes of a hub forging were proposed, characterized by large material savings in comparison with typical technology. The first process is based on forming without flash of a forging with axial cavity. The second one is connected with forming of forging from pipe billet. The realization of these processes is possible at the application of a press with three movable working tools. Theoretical research works were done on the basis of simulations by means of finite element method. Simulations were made mainly in order to determine kinematics of material flow in forging processes and precision of shape and dimensions of obtained products. The first of the proposed processes was experimentally verified and a product of good quality was obtained. Material consumption of the analyzed processes and other factors acting on their effectiveness were also compared.

Trockenrundkneten*/Dry rotary swaging

2015 ◽  
Vol 105 (11-12) ◽  
pp. 830-835
Author(s):  
F. Böhmermann ◽  
H. Hasselbruch ◽  
M. Herrmann ◽  
O. Riemer ◽  
A. Mehner ◽  
...  
Keyword(s):  
Tool Wear ◽  
Metal Forming ◽  
Work Piece ◽  
Light Weight ◽  
Forming Process ◽  
Bulk Metal ◽  
Structured Surfaces ◽  
Bulk Metal Forming ◽  
Rotary Swaging ◽  
Metal Forming Process

Rundkneten ist ein Massivumformverfahren zur Herstellung von Leichtbaukomponenten aus zylindrischen Halbzeugen. Es setzt derzeit einen intensiven Einsatz von Schmiermitteln voraus, um Werkzeugverschleiß zu minimieren und die gewünschte Bauteilqualität bereitzustellen. In dieser Arbeit werden strukturierte und hartstoffbeschichtete Rundknetwerkzeuge vorgestellt. Strukturierung und Beschichtung ersetzen die Funktionen des Schmierstoffes und bilden die Grundlage für eine trockene Prozessführung.   Rotary swaging is an incremental bulk metal forming process for the manufacture of cylindrical light weight components. Nowadays, rotary swaging is carried out under the extensive use of lubricant to avoid abrasive and adhesive tool wear and to provide the desired work piece quality. This work presents rotary swaging tools exhibiting hard coated and structured surfaces substituting the function of the lubricant and allowing for a successful dry rotary swaging.

scholarly journals Eccentric rotary swaging variants

2018 ◽  
Vol 190 ◽  
pp. 15003 ◽  
Author(s):  
Anastasiya Toenjes ◽  
Svetlana Ishkina ◽  
Christian Schenck ◽  
Axel von Hehl ◽  
Hans-Werner Zoch ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Material Flow ◽  
Material Structure ◽  
Thermal Treatments ◽  
Forming Process ◽  
Cold Forming ◽  
Rotary Swaging ◽  
Feed Direction ◽  
Multi Stage ◽  
Stage Process

Rotary swaging is an incremental cold forming process that changes beneath the geometry also the microstructure and mechanical properties of workpiece. Especially a new process design with Eccentric Flat Shaped Dies (EFSD) influences both the kind and amount of stress and plastic strain and consequently the material structure and hence the material and workpiece properties. Eccentric rotary swaging typically provides a helical material flow. According to the process parameters the microstructure features a typical eddy pattern with a spiral shaped grain orientation. The forming process can be carried out in one or more process steps. In a multi-stage process, it is possible to change the feed direction and, hence, the material flow helix direction. This approach can be used as a possibility to improve the homogeneity of the workpiece and material properties. In addition, for this aims an intermediate heat treatment in multi-stage forming operations could be realised. Following the goal of optimising the final properties, the question arises how these mechanical and thermal treatments affect the material microstructure and the forming properties of the workpiece and how they interact. Experiments were conducted with austenitic stainless steel rods of grade AISI304. The effects of the varied feed direction, feed velocity and heat treatment between the forming operations are discussed.

The Effect of Forming Speed on the Formability of a Zr-Based Bulk Metallic Glass

2015 ◽  
Vol 1088 ◽  
pp. 265-271 ◽  
Author(s):  
Wu Xiao ◽  
Jian Jun Li ◽  
Zhi Zhen Zheng ◽  
Jin Yang Li
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Wall Thickness ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Outer Diameter ◽  
Liquid Region ◽  
Forming Process ◽  
Element Analysis ◽  
Extrusion Forming

Taking cup-shaped part (outer diameter D and wall thickness are chosen as 2.2 mm and 0.05 mm, respectively) as an example, the micro-back-extrusion forming process of a Zr55Cu30 Al10Ni5 bulk metallic glass (BMG) in its supercooled liquid region was studied by using finite-element analysis (FEM) and experiment. The effect of forming speed on the formability was analyzed based on the extrusion load, the rheological behavior of the material and the microstructure of the formed parts. It was found that while the forming speed is below than 4 μm/s, the extrusion load increases obviously with the increasing in forming speed, otherwise, the BMG will follow non-newtonian flow and the forming load is insensitive to the forming speed. The parts fabricated at 2 μm/s are obviously crystallized due to the long retention time of metallic glasses at high temperature, a higher forming speed is benefit to enhancing the formability if the BMG. On this basis, micro cup-shaped parts with only 0.05 mm in wall thickness are successfully extruded.

Product Geometry for Process Parameter during Rotary Swaging Process as Chipless Forming Process

2007 ◽  
Vol 544-545 ◽  
pp. 439-442
Author(s):  
Seong Joo Lim ◽  
Ho Joon Choi ◽  
Duk Jae Yoon ◽  
Ha Guk Jeong ◽  
C.H. Lee
Keyword(s):  
Process Parameters ◽  
Metal Flow ◽  
Dimensional Accuracy ◽  
Outer Diameter ◽  
Important Process ◽  
Percent Reduction ◽  
Forming Process ◽  
Cross Sectional ◽  
Rotary Swaging ◽  
Available Information

This study deals with the dimensional accuracy of outer diameter and geometrical workability in rotary swaged product for various process parameters such as percent reduction in outer diameter and the ratio of thickness to outer diameter of a tube. It is generally known that greater cold strengthening is achieved by rotary swaging process rather than by conventional process such as rolling with respect to the same reduction of cross-sectional area. Percent reduction in the diameter and the ratio are considered and selected as important process parameters because of playing a key role during rotary swaging process. In case of tube under rotary swaging process the ratios have influence on geometrically proper workability without defect for different percent reductions in the diameter. In addition the change of metal flow of workpiece under the swaging process is microscopically and globally observed to analyze the reason why dimensional accuracy of the outer diameter of final product is improved after the rotary swaging process. This work might provide available information for the optimum rotary swaging process.

Research on Variation of Stress and Strain Field and Wall Thickness during Cone Spinning

2006 ◽  
Vol 532-533 ◽  
pp. 149-152 ◽  
Author(s):  
Mei Zhan ◽  
He Yang ◽  
Jin Hui Zhang ◽  
Yin Li Xu ◽  
Fei Ma
Keyword(s):  
Wall Thickness ◽  
Large Strain ◽  
Metal Flow ◽  
Small Region ◽  
Small Ring ◽  
Forming Process ◽  
Optimization Of Process Parameters ◽  
Spinning Process ◽  
Metal Forming Process ◽  
In The Beginning

Cone spinning is an advanced but complex metal forming process under coupled effects of multi-factors. Understanding the deformation mechanism, i.e., the stresses, strains, and metal flow in the deformation zone during the process is of great significance for optimizing the spinning process and controlling the product quality. In this paper, based on ABAQUS/Explicit, a reasonable FEM model for cone spinning with a single roller has been established, and the features of stress, strain and wall thickness during the process have been obtained. The results show the following: (1) In the beginning, large stress, large strain and the acute thinning of wall thickness localize at the small region below the roller, then the region extends into a small ring, further it becomes a large ring, and finally the ring will become uneven if the wrinkling occurs in the flange. (2) After spinning, the acute thinning region locates at the midst of the wall near the bottom of the workpiece. (3) At earlier stage of cone spinning, as a result of the acute thinning of wall thickness in the wall zone, the unevenness of wall thickness increases sharply to a value, then it almost keeps the value at the stable stage, and finally it will slowly increase again if the wrinkling appears in the flange. The results are helpful for determination and optimization of process parameters of cone spinning.

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