Forming Behavior of Thin Foils

2011 ◽  
Vol 473 ◽  
pp. 1008-1015 ◽  
Author(s):  
Zhen Yu Hu ◽  
Hanna Wielage ◽  
Frank Vollertsen
Keyword(s):  
Deep Drawing ◽  
Optical Measurement ◽  
Flow Behavior ◽  
Flow Behaviour ◽  
Forming Limit ◽  
Drawing Ratio ◽  
Local Flow ◽  
Micro Deep Drawing ◽  
Thin Foils ◽  
Application Potential

Due to size effects new challenges are involved in micro deep drawing compared to macro deep drawing. One of these challenges is that the limit drawing ratio in micro deep drawing becomes smaller than that in macro forming, which limits the application potential of micro deep drawing in an industrial context. In order to extend the application possibilities of micro deep drawing, investigations were carried out on this topic. Own previous work showed that the “tribological effect”, the “global flow behaviour effect” and the “local flow behaviour effect” are responsible for the lower forming limit in the micro range. In this paper, the flow behavior of thin foils is further investigated. Forming limit diagrams of Al99.5 and E-Cu foils with different thicknesses ranging from 20 μm to 100 μm were acquired using an optical measurement system. It was found that the forming limit of thin foils is lower than that of thicker foils. Further analysis indicates that this difference is due to the number of grains in the direction of thickness of the material: more grains give more grain boundaries, which allows more strain of the grains.

An Analysis of Forming Limit in Micro Deep Drawing of the Square Cup for Anisotropic Foil

2011 ◽  
Vol 105-107 ◽  
pp. 344-347
Author(s):  
Fung Huei Yeh ◽  
Ching Lun Li ◽  
Kun Nan Tsay
Keyword(s):  
Deep Drawing ◽  
Thickness Distribution ◽  
Forming Limit Diagram ◽  
Experimental Results ◽  
Forming Limit ◽  
Drawing Ratio ◽  
Micro Deep Drawing ◽  
Alloy Foil ◽  
Explicit Dynamic ◽  
Good Agreement

This paper presents an explicit dynamic finite element method (FEM) in conjunction with the forming limit diagram (FLD) to analyze the forming limit for the SPCC foil in micro deep drawing of square cup. In the present study, the tensile, anisotropic and friction test are performed to obtain the material parameters of the alloy foil according to the ASTM standards. Importing these properties, the numerical analysis is conducted by the explicit dynamic FEM. The FLD in numerical simulation is used as the criterion of the forming limit in micro deep drawing of the square cup. The forming limit, punch load-stroke relationship, deformed shape and thickness distribution of square cup, are discussed and compared with the experimental results. It shows that a good agreement is achieved from comparison between simulated and experimental results. The limit drawing ratio in micro deep drawing of square cup is 2.08 in this paper. From this investigation, the results of this paper can be used as reference in the relative researches and applications of micro forming.

An Analysis of Forming Limit for Various Arc Radii of Punch in Micro Deep Drawing of the Square Cup

2012 ◽  
Vol 433-440 ◽  
pp. 660-665
Author(s):  
Fung Huei Yeh ◽  
Ching Lun Li ◽  
Kun Nan Tsay
Keyword(s):  
Deep Drawing ◽  
Thickness Distribution ◽  
Forming Limit Diagram ◽  
Experimental Results ◽  
Forming Limit ◽  
Drawing Ratio ◽  
Micro Deep Drawing ◽  
Punch Load ◽  
Explicit Dynamic ◽  
Good Agreement

This paper presents an explicit dynamic finite element method (FEM) in conjunction with the forming limit diagram (FLD) to analyze the forming limit for the various arc radii of punch in micro deep drawing of square cup. In the present study, the tensile test and friction test are performed to obtain the material parameters of the electro-deposited copper foil according to the ASTM standards. Importing these properties, the numerical analysis is conducted by the explicit dynamic FEM. The FLD in numerical simulation is used as the criterion of the forming limit in micro deep drawing of the square cup. The forming limit, deformed shape, punch load-stroke relationship, height of cup and thickness distribution of square cup, are discussed and compared with the experimental results. It shows that a good agreement is achieved from comparison between simulated and experimental results. When the arc radii of punch increase with Rp=0.2, 0.5 and 0.8mm, the limit drawing ratio increases from 1.90 to 2.03 and 2.10. The forming limit of square cup increases with an increase of the arc radii of punch. From this investigation, the results of this paper can be used as reference in the relative researches and applications of micro forming.

Magnesium Sheet Metal Forming Considering its Specific Yield Behavior

2005 ◽  
Vol 6-8 ◽  
pp. 771-778 ◽  
Author(s):  
M. Redecker ◽  
Karl Roll ◽  
S. Häussinger
Keyword(s):  
Sheet Metal ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Specific Yield ◽  
Forming Limit ◽  
Forming Process ◽  
Local Flow ◽  
Yield Behavior ◽  
Magnesium Sheet ◽  
Testing Procedures

In recent years very strong efforts have been undertaken to build light weight structures of car bodies in the automotive industry. Structural technologies like Space Frame, tailored blanks and relief-embossed panels are well-known and already in use. Beside that there is a large assortment of design materials with low density or high strength. Magnesium alloys are lighter by approximately 34 percent than aluminum alloys and are considered to be the lightest metallic design material. However forming processes of magnesium sheet metal are difficult due to its complex plasticity behavior. Strain rate sensitivity, asymmetric and softening yield behavior of magnesium are leading to a complex description of the forming process. Asymmetric yield behavior means different yield stress depending on tensile or compressive loading. It is well-known that elevated temperatures around 200°C improve the local flow behavior of magnesium. Experiments show that in this way the forming limit curves can be considerably increased. So far the simulation of the forming process including temperature, strain rates and plastic asymmetry is not state-of-the-art. Moreover, neither reliable material data nor standardized testing procedures are available. According to the great attractiveness of magnesium sheet metal parts there is a serious need for a reliable modeling of the virtual process chain including the specification of required mechanical properties. An existing series geometry which already can be made of magnesium at elevated temperatures is calculated using the finite element method. The results clarify the failings of standard calculation methods and show potentials of its improvement.

Identification for Technological Capabilities of Titanium and Aluminum Alloys in Deep Drawing Process

2020 ◽  
Vol 299 ◽  
pp. 628-633 ◽  
Author(s):  
S.I. Feoktistov ◽  
Kyaw Zayar Soe
Keyword(s):  
Aluminum Alloys ◽  
Deep Drawing ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Work Piece ◽  
Drawing Ratio ◽  
Drawing Process ◽  
Variable Parameters ◽  
Deep Drawing Process ◽  
The Moment

The paper describes a method which has been developed for obtaining the limiting drawing ratio of titanium and aluminum alloys, and determines the moment of failure of the work-piece. This method is based not only on the use of Forming Limit Diagram (FLD) in predicting the failure of the blank, but also the using method of variable parameters of elasticity in determining the stress-strain state in deep drawing process.

scholarly journals Experimental and Simulation investigations of Micro Flexible Deep Drawing Using Floating Ring Technique

2018 ◽  
Vol 14 (3) ◽  
pp. 20-31
Author(s):  
Zaid H. Mahmood ◽  
Ihsan K. Irthiea ◽  
Kadum A. Abed
Keyword(s):  
Deep Drawing ◽  
Metal Forming ◽  
Simulation Models ◽  
Forming Process ◽  
Flexible Tool ◽  
Micro Deep Drawing ◽  
High Production Rate ◽  
Commercial Code ◽  
Application Potential ◽  
Set Up

Micro metal forming has an application potential in different industrial fields. Flexible tool-assisted sheet metal forming at micro scale is among the forming techniques that have increasingly attracted wide attention of researchers. This forming process is a suitable technique for producing micro components because of its inexpensive process, high quality products and relatively high production rate. This study presents a novel micro deep drawing technique through using floating ring as an assistant die with flexible pad as a main die. The floating ring designed with specified geometry is located between the process workpiece and the rubber pad. The function of the floating ring in this work is to produce SS304 micro cups with profile radius precision as required as possible. The finite element simulations are accomplished using the commercial code Abaqus/Standard. In order to verify the simulation models, micro deep drawing experiments are carried out using a special set up developed specifically to meet the requirements of the simulations. The results revealed that the proposed technique is feasible to be adopted for producing micro cups with remarkable application capability in miniaturization technology.

On the limit drawing ratio of magnetron sputtered aluminium–scandium foils within micro deep drawing

2010 ◽  
Vol 4 (5) ◽  
pp. 451-456 ◽  
Author(s):  
Frank Vollertsen ◽  
Zhenyu Hu ◽  
Heinz-Rolf Stock ◽  
Bernd Koehler
Keyword(s):  
Deep Drawing ◽  
Drawing Ratio ◽  
Limit Drawing Ratio ◽  
Micro Deep Drawing

Micro Deep Drawability of the Superplastic Zn–22Al Alloy at a High Strain Rate and Room Temperature

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Mehmet Emin Çetin ◽  
Ömer Necati Cora ◽  
Hasan Sofuoğlu
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Deep Drawing ◽  
Room Temperature ◽  
High Strain ◽  
Equal Channel Angular Extrusion ◽  
Thickness Variation ◽  
Drawing Ratio ◽  
Deep Drawability ◽  
Micro Deep Drawing

Abstract This study aimed to investigate the micro deep drawability of the Zn–22Al alloy at room temperature in which it shows superplastic properties. To this goal, first the two-step equal channel angular extrusion (ECAE) process was carried out to obtain an ultra-fine-grained structure (UFG). Upon achieving the grain size of 200 nm, the formability of the alloy at room temperature and at a high strain rate was investigated both experimentally and numerically. Micro deep drawing experiments were performed at different deep drawing ratios (1.66, 1.84, 2.0, and 2.25) and for different sheet thicknesses (0.2, 0.4, and 0.6 mm). The finite element model of the micro deep drawing was also established to assess and compare the thickness variation in deep drawn parts. Results showed that the superplastic Zn–22Al alloy has a great potential in microforming applications. It was also noted that the limiting drawing ratio can be obtained as high as 2.25 in the room temperature condition.

scholarly journals Experimental and Simulation investigations of Micro Flexible Deep Drawing Using Floating Ring Technique

2018 ◽  
Vol 14 (3) ◽  
pp. 20-31 ◽  
Author(s):  
Zaid H. Mahmood ◽  
Ihsan K. Irthiea ◽  
Kadum A. Abed
Keyword(s):  
Deep Drawing ◽  
Metal Forming ◽  
Simulation Models ◽  
Forming Process ◽  
Flexible Tool ◽  
Micro Deep Drawing ◽  
High Production Rate ◽  
Commercial Code ◽  
Application Potential ◽  
Set Up

Micro metal forming has an application potential in different industrial fields. Flexible tool-assisted sheet metal forming at micro scale is among the forming techniques that have increasingly attracted wide attention of researchers. This forming process is a suitable technique for producing micro components because of its inexpensive process, high quality products and relatively high production rate. This study presents a novel micro deep drawing technique through using floating ring as an assistant die with flexible pad as a main die. The floating ring designed with specified geometry is located between the process workpiece and the rubber pad. The function of the floating ring in this work is to produce SS304 micro cups with profile radius precision as required as possible. The finite element simulations are accomplished using the commercial code Abaqus/Standard. In order to verify the simulation models, micro deep drawing experiments are carried out using a special set up developed specifically to meet the requirements of the simulations. The results revealed that the proposed technique is feasible to be adopted for producing micro cups with remarkable application capability in miniaturization technology.

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