Influence of Continuous Direct Current on the Micro Tube Hydroforming Process

2011 ◽  
Author(s):  
Scott W. Wagner ◽  
Kenny Ng ◽  
William J. Emblom ◽  
Jaime A. Camelio
Keyword(s):  
Direct Current ◽  
Metal Forming ◽  
High Pressures ◽  
Tube Hydroforming ◽  
Electrical Current ◽  
Deformation Energy ◽  
Electrically Assisted ◽  
Macro Scale ◽  
Hydroforming Process ◽  
Electrically Assisted Manufacturing

Research of the micro tube hydroforming (MTHF) process is being investigated for potential medical and fuel cell applications. This is largely due to the fact that at the macro scale the tube hydroforming (THF) process, like most metal forming processes has realized many advantages. Unfortunately, large forces and high pressures are required to form the parts so there is a large potential to create failed or defective parts. Electrically Assisted Manufacturing (EAM) and Electrically Assisted Forming (EAF) are processes that apply an electrical current to metal forming operations. The intent of both EAM and EAF is to use this applied electrical current to lower the metals required deformation energy and increase the metal’s formability. These tests have allowed the metals to be formed further than conventional methods without sacrificing strength or ductility. Currently, various metal forming processes have been investigated at the macro scale. These tests also used a variety of materials and have provided encouraging results. However, to date, there has not been any research conducted that documents the effects of applying Electrically Assisted Manufacturing (EAM) techniques to either the tube hydroforming process (THF) or the micro tube hydroforming process (MTHF). This study shows the effects of applying a continuous direct current to the MTHF process.

Influence of Continuous Direct Current on the Microtube Hydroforming Process

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Scott W. Wagner ◽  
Kenny Ng ◽  
William J. Emblom ◽  
Jaime A. Camelio
Keyword(s):  
High Pressures ◽  
Tube Hydroforming ◽  
Electrical Current ◽  
Deformation Energy ◽  
Recrystallization Temperature ◽  
Machining Processes ◽  
Electrically Assisted ◽  
Stainless Steel 304 ◽  
Hydroforming Process ◽  
Electrically Assisted Manufacturing

Research of the microtube hydroforming (MTHF) process is being investigated for potential medical and fuel cell applications. This is largely due to the fact that at the macroscale the tube hydroforming (THF) process, like most metal forming processes, has realized many advantages, especially when comparing products made using traditional machining processes. Unfortunately, relatively large forces compared to part size and high pressures are required to form the parts so the potential exists to create failed or defective parts. One method to reduce the forces and pressures during MTHF is to incorporate electrically assisted manufacturing (EAM) and electrically assisted forming (EAF) into the MTHF. The intent of both EAM and EAF is to use electrical current to lower the required deformation energy and increase the metal's formability. To reduce the required deformation energy, the applied electricity produces localized heating in the material in order to lower the material's yield stress. In many cases, the previous work has shown that EAF and EAM have resulted in metals being formed further than conventional forming methods alone without sacrificing the strength or ductility. Tests were performed using “as received” and annealed stainless steel 304 tubing. Results shown in this paper indicate that the ultimate tensile strength and bust pressures decrease with increased current while using EAM during MTHF. It was also shown that at high currents the microtubes experienced higher temperatures but were still well below the recrystallization temperature.

Effect of Continuous Direct Current on the Yield Stress of Stainless Steel 304 Micro Tubes During Hydroforming Operations

2012 ◽  
Author(s):  
Scott W. Wagner ◽  
Kenny Ng ◽  
William J. Emblom ◽  
Jaime A. Camelio
Keyword(s):  
Mechanical Properties ◽  
Yield Stress ◽  
High Pressures ◽  
Tube Hydroforming ◽  
Process Equipment ◽  
Traditional Methods ◽  
Macro Scale ◽  
Hydroforming Process ◽  
Superior Mechanical Properties ◽  
Electrically Assisted Manufacturing

Hydroforming at the macro scale offers the opportunity to create products that have superior mechanical properties and intricate complex geometries. Micro tube hydroforming is a process that is gaining popularity for similar reasons. At the same time, due to the physical size of the operations, there are many challenges including working with extremely high pressures and available materials that are typically difficult to form. Increasing the formability of micro tubes during the hydroforming process is desired. Being able to increase the formability is essential because as the tube diameters decrease in size, the required forming pressure increases. As a result, it is important to explore methods to decrease the yield stress during forming operations. Traditional methods for decreasing the materials yield stress typically involve heating either the sample or the process equipment. Using traditional methods typically sacrifice dimensional quality of the part, alter the mechanical properties and also raise the costs of the operations. Electrically Assisted Manufacturing (EAM) is a non-traditional method that is gaining popularity by reducing the necessary forces and pressures required in metal forming operations.

An Investigation of Anisotropic Behavior on 5083 Aluminum Alloy Using Electric Current

2013 ◽  
Author(s):  
Abram D. Pleta ◽  
Matthew C. Krugh ◽  
Chetan Nikhare ◽  
John T. Roth
Keyword(s):  
Metal Forming ◽  
Electrical Current ◽  
Research Area ◽  
Metallic Materials ◽  
Anisotropic Behavior ◽  
Current Application ◽  
Electrically Assisted ◽  
Dc Current ◽  
Electrically Assisted Manufacturing ◽  
5083 Aluminum Alloy

Due to more stringent environmental regulations, the demand for strong, lightweight metal alloys, such as AA 5083, has increased. In sheet metal forming, aluminum is preferred over higher density steels to manufacture such parts; however the in-plane anisotropic behavior of AA 5083 alloy greatly affects its formability. Previous researchers have found that mechanical properties of metallic materials can be influenced by DC electrical current, a research area known as Electrically-Assisted Manufacturing (EAM). The research herein is focused on characterizing the in-plane anisotropic behavior of AA 5083 alloy with and without DC current application, while it is loaded in the uniaxial direction. Furthermore, the effects of EAM on Lueder’s banding will also be investigated.

Force Controlled Electrical Pulse Assisted Forming

2020 ◽  
Author(s):  
Tyler J. Grimm ◽  
Amit B. Deshpande ◽  
Laine Mears ◽  
Jianxun Hu
Keyword(s):  
Control Systems ◽  
Stress Level ◽  
Stress Reduction ◽  
Power Supply ◽  
Electrical Current ◽  
Strain Rates ◽  
Control Approach ◽  
Electrically Assisted ◽  
Minimum Stress ◽  
Electrically Assisted Manufacturing

Abstract Electrically-assisted manufacturing refers to the direct application of electrical current to a workpiece during a manufacturing process. This assistance results in several benefits such as flow stress reduction, increased elongation, reduced springback, increased diffusion, and increased precipitation control. These effects are also associated with traditional thermal assistance. However, for over half a decade it has been argued whether or not these observed effects are due to electroplasticity, a term which describes effects that cannot be fully explained through resistive heating. Several theories have been proposed as to the mechanism responsible for these purported athermal effects. Conflicting results within literature have enabled this debate over electroplasticity since its discovery in the mid 20th century. While the effects of electrically-assisted manufacturing are clearly characterized throughout literature, there is a lack of research related to control systems which may be used to take advantage of its effects. Typically, control systems are developed using an empirical approach, requiring extensive testing in order to fully characterize the stress-strain behavior at all conditions. Additionally, current research has primarily focused on reducing flow stresses during electrically-assisted processes without regard for the strength of the material subsequent to forming. Therefore, there is a strong need for a control system which can quickly be deployed for new materials and does not significantly reduce the subsequent strength of the material. Herein, a novel control approach is developed in which electrical pulses are triggered by a predetermined stress level. This stress value would be set according to the manufacturer’s stamping die strength. Once the material reaches this stress value, current is deployed until a minimum stress level is reached. At that point, the electricity is turned off and the material allowed to cool; at that stage the stress begins to elevate and the cycle continues. This approach does not require extensive pre-testing and is robust to a range of strain rate. This type of implementation can also be adapted to different levels of capability. For example, since the current is controlled by force and not by time, a low-current power supply will stay on for each pulse longer than a power supply with higher capabilities; however, each will achieve a similar effect. This study investigates the effect of several different minimum stress levels and strain rates. The strain rates chosen are relatively similar to common stamping process. This system was experimentally tested using 1018 CR steel. This control approach was found to be a successful method of maintaining a desired stress level.

Numerical analysis in a beverage can utilizing tube hydroforming process

2019 ◽  
Vol 28 (6) ◽  
pp. 77-83
Author(s):  
Jorge Carlos León Anaya ◽  
José Antonio Juanico Loran ◽  
Juan Carlos Cisneros Ortega
Keyword(s):  
Mechanical Properties ◽  
Numerical Analysis ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Forming Process ◽  
Aluminum Tube ◽  
Plastic Deformation Process ◽  
Metal Forming Process ◽  
Hydroforming Process

Numerical analysis for Tube Hydroforming (THF) was developed in this work to predict the behavior of extruded aluminum tube in a forming die for beverage can applications. THF is a metal forming process dependent of three parameters: friction between the tube and the die, internal pressure, and material properties of the tube. Strain hardening is a governing phenomenon that occurs in the plastic deformation process of metals. Hollomon’s equation offers a mathematical description of the metal behavior in the plastic zone. For a proper simulation, experimental determination of the mechanical properties of aluminum 6061-T5 were conducted and test specimens where obtained directly from the aluminum tube. Experimental data were necessary because no sufficient data of the mechanical properties of the tube were available in the literature. Numerical simulations of THF were performed, and the results were compared with analytical results for validation purposes with less than 10% of error.

Reliability Analysis of the Tube Hydroforming Process Based on Forming Limit Diagram

2005 ◽  
Vol 128 (3) ◽  
pp. 402-407 ◽  
Author(s):  
Bing Li ◽  
Don R. Metzger ◽  
Tim J. Nye
Keyword(s):  
Automotive Industry ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Forming Limit Diagram ◽  
Probability Of Failure ◽  
Alternative Methods ◽  
Forming Limit ◽  
Forming Process ◽  
Hydroforming Process ◽  
Free Bulging

Tube hydroforming is an attractive manufacturing process in the automotive industry because it has several advantages over alternative methods. In order to determine the reliability of the process, a new method to assess the probability of failure is proposed in this paper. The method is based on the reliability theory and the forming limit diagram, which has been extensively used in metal forming as the criteria of formability. From the forming limit band in the forming limit diagram, the reliability of the forming process can be evaluated. A tube hydroforming process of free bulging is then introduced as an example to illustrate the approach. The results show this technique to be an innovative approach to avoid failure during tube hydroforming.

Effect of Heat Treatment Conditions on Tube Hydroforming Characteristics of Aluminum Alloy

2013 ◽  
Vol 535-536 ◽  
pp. 275-278
Author(s):  
Myeong Han Lee ◽  
Young Chul Shin ◽  
Duk Jae Yoon
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Treatment Processes ◽  
Forming Technology ◽  
Treatment Conditions ◽  
Compressive Loads ◽  
Hydroforming Process

Tube hydroforming is a metal forming technology that utilizes internal pressure and axial compressive loads to generate designed product shapes with complex sections from tubular materials. The tube hydroforming process has been used in the automotive, aircraft, and bicycle industries for many years. With the pursuit of lighter bicycles, aluminum alloys have been utilized as an alternative to steel. To obtain adequate strength, the aluminum alloys should undergo heat treatment processes before being used. However, the mechanical properties of the alloys vary with the tempering conditions. This paper aims to evaluate the effects of tube hydroforming characteristics on different kinds of tempered aluminum alloys. Based on numerical simulations, suitable tube hydroforming processing conditions for each tempered aluminum alloy are suggested.

A Process Comparison of Simple Stretch Forming Using Both Conventional and Electrically-Assisted Forming Techniques

2010 ◽  
Author(s):  
Joshua J. Jones ◽  
Laine Mears
Keyword(s):  
Sheet Metal ◽  
Manufacturing Process ◽  
Electrical Current ◽  
Stretch Forming ◽  
Forming Process ◽  
Process Comparison ◽  
Directional Flow ◽  
Direct Electrical Current ◽  
Electrically Assisted ◽  
Electrically Assisted Manufacturing

A common manufacturing process typically used to create large surface contours in sheet metal is stretch forming. With this process, the ability to create geometrically accurate parts and smooth surfaces is achievable, yet there are certain limits when considering the achievable elongation of the material and the inability to produce sharp contours in the sheet metal. Present research using Electrically-Assisted Manufacturing (EAM) has shown that applying direct electrical current to the workpiece during the forming process can increase the formability and reduce springback of the material, while also lowering the required forming forces. Seeing the advantageous qualities of EAM, this study examines the use of EAM for a simple stretch forming process. Specifically, this research examines this stretch forming process with regards to how the location where the electrical current is applied to the material affects the process, the achievable forming depth without fracture, and the application direction of the current. Overall results displayed that the directional flow of electrical current and the application location did not affect the obtained forming forces or forming depths using EAM.

Self-Adjusting Characterization for Steady-State, Direct Current Cathode-Dominated Glow Discharge Plasmas at High Pressures

2013 ◽  
Vol 30 (8) ◽  
pp. 085201 ◽  
Author(s):  
Fang Ding ◽  
Shi-Jian Zheng ◽  
Bo Ke ◽  
Zhong-Liang Tang ◽  
Yi-Chuan Zhang ◽  
...  
Keyword(s):  
Steady State ◽  
Glow Discharge ◽  
Direct Current ◽  
High Pressures ◽  
Discharge Plasmas
Sign in / Sign up

Export Citation Format

Share Document