Effect of DC Current on the Formability of 6Al 4V Titanium

2006 ◽  
Author(s):  
Carl D. Ross ◽  
Thomas J. Kronenberger ◽  
John T. Roth
Keyword(s):  
Electrical Current ◽  
Dramatic Improvement ◽  
Metallic Materials ◽  
Resistive Heating ◽  
Applied Current ◽  
Superplastic Behavior ◽  
Compressive Loads ◽  
Current Densities ◽  
Dc Current ◽  
Electron Wind

Recent research has demonstrated that the mechanical properties of metallic materials are altered when an electrical current is passed through the material. These studies suggest that titanium, due to its low formability and potential for dramatic improvement, should be subjected to additional study. The research presented herein further investigates the use of electricity to aid in the bulk deformation of 6Al-4V titanium under tensile and compressive loads. Extensive testing is presented that documents the changes that occur in the formability of titanium due to the presence of an electron wind at varying current densities. Using carefully designed experiments, this study also characterizes and isolates the effect of resistive heating from the change due to the electrical flow alone. The results demonstrate that the presence of an electrical current within the material during deformation can greatly decrease the force needed to deform titanium while also dramatically enhancing the degree to which it can be worked without fracturing. Isothermal testing further demonstrates that the changes are significantly beyond that which can be accounted for due to increases in the titanium’s temperature. The results are also supported by data from tests using pulsed and discontinuously applied current. Furthermore, current densities are identified that cause an apparent superplastic behavior to occur. Overall, this work fully demonstrates that an electrical current can be used to significantly improve the formability of 6Al-4V titanium and that these improvements far exceed that which can be explained by resistive heating.

Effect of dc on the Formability of Ti–6Al–4V

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Carl D. Ross ◽  
Thomas J. Kronenberger ◽  
John T. Roth
Keyword(s):  
Mechanical Properties ◽  
Mechanical Loading ◽  
Electrical Current ◽  
Dramatic Improvement ◽  
Bulk Deformation ◽  
Resistive Heating ◽  
Applied Current ◽  
Designed Experiments ◽  
Compressive Loads ◽  
Current Densities

Recent research has demonstrated that the mechanical properties of metals are altered when an electrical current is passed through the material. These studies suggest that titanium alloys, due to their low formability and need for dramatic improvement, should be subjected to additional study. The research presented herein further investigates the use of electricity to aid in the bulk deformation of Ti–6Al–4V under tensile and compressive loads. Extensive testing is presented, which documents the changes that occur in the formability of titanium due to the presence of an electrical current at varying current densities. Using carefully designed experiments, this study also characterizes and isolates the effect of resistive heating from the overall effect due to the electrical flow. This study clearly indicates that electrical flow affects the material beyond that which can be explained through resistive heating. The results demonstrate that an applied electrical current within the material during mechanical loading can greatly decrease the force needed to deform the titanium while also dramatically enhancing the degree to which it can be worked without fracturing. Isothermal testing further demonstrates that the changes are significantly beyond that which can be accounted for due to increases in the titanium’s temperature. The results are also supported by data from tests using pulsed and discontinuously applied current. Furthermore, current densities are identified that cause an enhanced formability behavior to occur. Overall, this work fully demonstrates that an electrical current can be used to significantly improve the formability of Ti–6Al–4V and that these improvements far exceed that which can be explained by resistive heating.

Compressive Superplastic Behavior of 6Al-4V Titanium Caused by an Applied DC Current

2006 ◽  
Author(s):  
Thomas J. Kronenberger ◽  
Matthew K. Warner ◽  
John T. Roth
Keyword(s):  
Electrical Current ◽  
Related Phenomenon ◽  
Metallic Materials ◽  
Compression Tests ◽  
Total Deformation ◽  
Superplastic Behavior ◽  
Cross Sectional ◽  
Current Densities ◽  
Dc Current ◽  
Frictional Effects

Recent research has shown that the flow stress necessary to deform certain metallic materials can be decreased when an electrical current is present in the material while undergoing deformation. As part of this testing, it was found that, under higher current densities, the various metals began to exhibit strain weakening and superplastic behavior (i.e., the stress either remained constant or decreased as the strain increased). During typical compression testing, it is expected that the stress will continually increase as the strain increases. This is due to the increase in the cross-sectional area of the test specimen as well as the frictional effects that are present between the specimen and the fixture throughout the test. Since this strain weakening and subsequent superplastic behavior is opposite of what typically occurs during normal low temperature compression tests, it introduces a new electrical current-related phenomenon. This paper contains a detailed investigation of superplastic behavior using experimental results, focusing on 6A1-4V Titanium in particular. To examine this phenomenon, compression tests are run at different current densities. Some tests are conducted with the electricity present the entire time, while other tests are conducted with the electricity turned off at various points within the superplastic region. Still other tests have a pulsed electrical current present. It will be shown that the superplastic behavior allows significant increases in total deformation to be achieved using extremely low forces.

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.

Processing Dense Hetero-Nanostructured Metallic Materials for Improved Strength/Ductility Balance through High Strain Deformation and Electrical Current Assisted Sintering (ECAS)

2009 ◽  
Vol 633-634 ◽  
pp. 559-567 ◽  
Author(s):  
Thierry Grosdidier ◽  
Núria Llorca-Isern
Keyword(s):  
High Strain ◽  
Milled Powder ◽  
Electrical Current ◽  
Processing Parameters ◽  
Metallic Materials ◽  
Bulk Materials ◽  
Multi Scale ◽  
Field Assisted Sintering ◽  
Y2o3 Addition ◽  
Powder Metallurgy Route

This paper has examined some recent findings concerning the processing of fully dense hetero-nanostructured materials (i.e. consisting of nano, ultrafine and micrometric grains) which can be produced by using the interplay between heavy deformation and recrystallization. By plastic deformation of bulk materials, an improved strength/ductility balance can be obtained directly by imparting high strain deformation (by ECAE) until the occurrence of recrystallization. Using a powder metallurgy route, the strong potential of electric field assisted sintering (ECAS) for producing multi-scale microstructures when a milled powder is used is also demonstrated. In this case, in addition to modify the classic processing parameters (time/temperature of ECAS), altering the nature of the milled powder - by Y2O3 addition during the milling stage - is also a good way to delay the onset of recrystallization and, thereby, increase the fraction of ultrafine grains.

scholarly journals Electro-Absorbers: A Comparison on Their Performance with Jet-Absorbers and Absorption Columns

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 653
Author(s):  
Monserrat Castañeda-Juárez ◽  
Martín Muñoz-Morales ◽  
Fernanda Lourdes Souza ◽  
Cristina Sáez ◽  
Pablo Cañizares ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Trichloroacetic Acid ◽  
Packed Column ◽  
Scale Up ◽  
Applied Current ◽  
Absorption Column ◽  
Applied Current Density ◽  
Current Densities ◽  
Surface Jet ◽  
By Products

This work focuses on the removal of perchloroethylene (PCE) from gaseous streams using absorbers connected with electrolyzers. Two types of absorption devices (jet absorber and absorption column) were compared. In addition, it has been evaluated the different by-products generated when a simultaneous electrolysis with diamond anodes is carried out. PCE was not mineralized, but it was transformed into phosgene that mainly derivates into carbon tetrachloride. Trichloroacetic acid was also formed, but in much lower amounts. Results showed a more efficient absorption of PCE in the packed column, which it is associated to the higher gas–liquid contact surface. Jet absorber seems to favor the production of carbon tetrachloride in gaseous phase, whereas the packed column promotes a higher concentration of trichloroacetic acid in liquid. It was also evaluated the scale up of the electrolytic stage of these electro-absorption devices by using a stack with five perforated electrode packages instead of a single cell. Clarification of the effect of the applied current density on the speciation attained after the electrolysis of the absorbent has been attempted. Experiments reveal similar results in terms of PCE removal and a reduced generation of gaseous intermediates at lower current densities.

Stability Analysis of Spin-Torque Nano-oscillator in the Rotating Frame

SPIN ◽  
2019 ◽  
Vol 09 (03) ◽  
pp. 1950008
Author(s):  
HaoHsuan Chen ◽  
Lang Zeng ◽  
ChingMing Lee ◽  
Weisheng Zhao
Keyword(s):  
High Performance ◽  
Electrical Current ◽  
Nonstationary Process ◽  
Laboratory Frame ◽  
Spin Torque ◽  
Rotating Frame ◽  
Magnetization Dynamics ◽  
Applied Current ◽  
Frequency Tunability ◽  
Out Of Plane

Spin-torque nano-oscillators (STNOs) have become one of the emerging and novel microwave devices with the high performance and tunability of GHz range frequency. The nanopillar structure with an out-of-plane (OP) spin polarizer and an in-plane (IP) magnetized free layer (FL) has been considered as a good candidate for the STNOs. Using the local rotational coordinate transformation, a nonstationary process describing magnetization dynamics in the laboratory frame is therefore transformed into a stationary one in the rotating frame. In this way, the state phase diagram of this type of STNOs is well established as a function of an applied current and external field, which is also evidenced by the macrospin simulations. Also, we show that the frequency tunability of the STNOs through electrical current can be well elevated by applying a static magnetic field anti-parallel to the spin-polarizer vector.

Electrical Current at Metal Cutting Process: A Literature Review

2015 ◽  
Vol 808 ◽  
pp. 40-47 ◽  
Author(s):  
Raluca Daicu ◽  
Gheorghe Oancea
Keyword(s):  
Literature Review ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Electrical Current ◽  
Cutting Edge ◽  
Cutting Process ◽  
Metallic Materials ◽  
Cutting Zone

Processing metallic materials by cutting using good electricity conductor cutting edges it appears an electrical current due mainly to the temperature in the cutting zone. Analyzing of the electrical current the information about the unfolding mode of the cutting process can be obtained. The cutting electrical current can be used in several applications: the estimation of the temperature in the cutting zone, the estimation of the cutting forces, the identification of the wear state of the cutting edge etc. The first researches were started in Russia and they were based on the utilization of the cutting electrical current to measure the temperature in the cutting zone. Afterwards, other applications were identified in the literature and the researches were extended in other countries like India, Japan, USA, Brazil, France, Bangladesh and Romania. This paper presents a review of the researches about the electrical current which appears at cutting process.

Polarization Studies of Aluminum Alloys In Water at 200 C and 300 C

CORROSION ◽  
1963 ◽  
Vol 19 (4) ◽  
pp. 146t-155t ◽  
Author(s):  
J. H. GREENBLATT ◽  
A. F. McMILLAN
Keyword(s):  
Anodic Polarization ◽  
Cathodic Polarization ◽  
Oxidation Potential ◽  
Electronic Conduction ◽  
Film Resistance ◽  
Applied Current ◽  
Weight Gain Data ◽  
Current Densities ◽  
Polarization Studies ◽  
Impressed Current

Abstract Specimens of commercial 2S aluminum and two special alloys containing iron and nickel were polarized anodically and cathodically at a number of different current densities at 200 C and 300 C. Weight gains were obtained and the potentials relative to the stainless steel autoclave were measured by an interrupter method. The weight gain data indicated that the polarizing current is being carried by electronic conduction. The potential-time curves for anodic polarization indicate differences between 2S aluminum and the alloys in that greater polarization is obtained with the latter. These curves also indicate that the impressed current decreases the film resistance. In all cases the potential reached a plateau value with time and this time was shorter for the alloys. The potential-time curves for cathodic polarization also show plateau values but the rise to a plateau value is in the opposite sense to the applied current. With increasing cathodic polarization the plateau values occur at more negative values of the potential. This latter trend is in the same direction as the applied polarizing current. This apparently is explained in terms of the build-up of the aluminum oxidation potential which acts in a sense opposite to the applied current. Again the time to reach plateau values was shorter for the alloys. Voltage current curves were also obtained on specimens left overnight (approximately 17 hours) at two different anodic polarizing currents. These curves indicated differences between 2S aluminum and the alloys; these differences are discussed in terms of the semi-conducting properties of the oxide film. The observations made on the differences in the properties of the oxide films on the materials examined as revealed by potential and polarization curves are discussed as to their significance in determining corrosion resistance.

Ultra-Fast NiSi2 Formation in p+-Si by High Current Densities

1998 ◽  
Vol 527 ◽  
Author(s):  
J.S. Huang ◽  
K.N. Tu
Keyword(s):  
Room Temperature ◽  
Line Length ◽  
Line Formation ◽  
High Current ◽  
Subsequent Growth ◽  
Applied Current ◽  
Electron Hole ◽  
Current Densities ◽  
Heavily Doped ◽  
Hole Recombination

ABSTRACTAn ultra-fast lateral formation of epitaxial NiSi2 line in heavily doped p+-Si diffused tub was created at room temperature ambient under the application of current densities of 106 A/cm2. A NiSi2 line of 140 μm long and I μm wide linking the cathode and anode contacts to p+-Si was formed within 1 second. Shorter lines were formed with lower current densities. The formation of shorter lines was again completed within 1 second and there was very little subsequent growth upon further stressing. The line length strongly depends upon applied current which tend to suggest that the line formation is limited by driving force rather than by kinetics. We propose that the ultra-fast silicide formation is a result of Ni interstitial diffusion in Si induced by electron-hole recombination heating and electromigration.

New Cathodic Protection Criteria Based on Direct and Alternating Current Densities Measured Using Coupons and Their Application to Modern Steel Pipelines

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 304-312 ◽  
Author(s):  
Y. Hosokawa ◽  
F. Kajiyama ◽  
Y. Nakamura
Keyword(s):  
Cathodic Protection ◽  
Field Tests ◽  
Alternating Current ◽  
Pipe Material ◽  
Review Of The Literature ◽  
Density Measurements ◽  
Corrosion Risk ◽  
Ac Current ◽  
Current Densities ◽  
Dc Current

Abstract The risks of alternating current (AC) corrosion, overprotection, and stray direct current (DC) corrosion are increasing on cathodically protected buried steel pipelines due to the recent changes in factors such as burial conditions, the characteristics of coatings, and pipe material. In the present study, field tests as well as a review of the literature on these risks were conducted. As a result, it has been revealed that there is a certain limitation to assess these risks with respect to conventional cathodic protection (CP) criteria based on pipe-to-soil potential. Therefore, new CP criteria for the elimination of these risks have been developed based on DC and AC current density measurements on coupons. The effectiveness of the new CP criteria was evaluated through the design of CP systems on newly constructed pipelines subject to the risks of AC corrosion, overprotection, and stray DC corrosion. Using these new CP criteria, the design and installation of CP systems as well as the elimination of these risks were completed successfully. The risks of overprotection as well as stray DC corrosion were eliminated by providing an appropriate level of DC current from CP rectifiers. The elimination of the AC corrosion risk was accomplished using distributed magnesium anodes and solid-state DC decoupling devices. Finally, the new CP criteria were proven to be effective in eliminating the risks of AC corrosion, overprotection, and stray DC corrosion on buried steel pipelines.

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