Influence of melting current pulse duration on microstructural features and mechanical properties of AA5083 alloy weldments

2019 ◽  
Vol 746 ◽  
pp. 167-178 ◽  
Author(s):  
Mustafa Umar ◽  
Paulraj Sathiya
Keyword(s):  
Mechanical Properties ◽  
Current Pulse ◽  
Pulse Duration ◽  
Current Pulse Duration ◽  
Aa5083 Alloy ◽  
Melting Current

Machining Characteristics of EDM Using Gas Media

2011 ◽  
Vol 189-193 ◽  
pp. 3123-3130 ◽  
Author(s):  
Yao Jang Lin ◽  
Yan Cherng Lin ◽  
A Cheng Wang ◽  
Yuan Feng Chen ◽  
Han Ming Chow
Keyword(s):  
Current Pulse ◽  
Pulse Duration ◽  
Air Pressure ◽  
Electrode Wear ◽  
Machining Parameters ◽  
Environment Impact ◽  
Current Pulse Duration ◽  
Machined Surface ◽  
Peak Current ◽  
Machining Characteristics

The aim of this study is to construct a diverse process of electrical discharge machining (EDM) in gas media, and then the new developed machining approach was used to investigate the effects of machining parameters on machining characteristics. Firstly, the feasibility of the EDM in gas media was established with consecutive electrical sparks generated within the machining gap. Moreover, the main machining parameters such as peak current, pulse duration, machining polarity, and gas media supply conditions like air compressed pressure were varied to evaluate the effects on machining characteristics of SKD 61 mold steel in the developed EDM process. The surface morphology of machined surface was observed by a scanning electronic microscope (SEM) to determine the influences of EDM discharge energy on surface integrities. From the result shown in experiments, the material removal rate (MRR) increased with peak current, pulse duration, and air pressure. In addition, the electrode wear rate (EWR) went up with peak current at first, and then attained a peak value with extending the pulse duration and the air pressure, but the EWR declined with further increasing of the pulse duration and the air pressure. Furthermore, the integrities of the machined surface revealed dramatically rough features when the peak current was set at high value. While the pulse duration was further extending, the surface integrities of the machined surface exhibited a smoothened trend obtained by EDM in gas media. Consequently, the developed technique of EDM in gas media possesses the potential of promoting machining performance, reducing environment impact, and extending the EDM applications.

scholarly journals Effect of current pulse duration in recovering quantitative induced polarization models from time-domain full-response and integral chargeability data

2019 ◽  
Vol 218 (3) ◽  
pp. 1739-1747 ◽  
Author(s):  
Per-Ivar Olsson ◽  
Gianluca Fiandaca ◽  
Pradip Kumar Maurya ◽  
Torleif Dahlin ◽  
Esben Auken
Keyword(s):  
Current Pulse ◽  
Pulse Duration ◽  
Time Domain ◽  
Induced Polarization ◽  
Current Pulse Duration ◽  
Polarization Models

Note: Measurement of extreme-short current pulse duration of runaway electron beam in atmospheric pressure air

2012 ◽  
Vol 83 (8) ◽  
pp. 086106 ◽  
Author(s):  
V. F. Tarasenko ◽  
D. V. Rybka ◽  
A. G. Burachenko ◽  
M. I. Lomaev ◽  
E. V. Balzovsky
Keyword(s):  
Electron Beam ◽  
Current Pulse ◽  
Pulse Duration ◽  
Atmospheric Pressure ◽  
Runaway Electron ◽  
Runaway Electron Beam ◽  
Current Pulse Duration

Electrochemical Micromachining Using Electrostatic Induction Feeding Method

2012 ◽  
Vol 523-524 ◽  
pp. 305-309 ◽  
Author(s):  
Tomohiro Koyano ◽  
Masanori Kunieda
Keyword(s):  
Current Pulse ◽  
Pulse Duration ◽  
Electrochemical Machining ◽  
Pulse Voltage ◽  
Electrochemical Micromachining ◽  
Current Pulse Duration ◽  
Feeding Method ◽  
Electrostatic Induction ◽  
Pulse On Time ◽  
Side Gap

This paper describes micro electrochemical machining (ECM) using the electrostatic induction feeding method. In ECM, electrolytic dissolution can be localized in the area where the gap width is narrow by using pulse durations shorter than several tens of nano-seconds. With the electrostatic induction feeding method which has been developed for micro electrical discharge machining, the current pulse of such short durations can be obtained more easily compared with the conventional pulse generators. In this study, the influences of the pulse voltage of power supply and feeding capacitance on the machining current were investigated theoretically. It was found that the current pulse duration is nearly equal to the rise time and fall time regardless of the pulse-on time of the pulse voltage. Hence, ultra-short pulses can be obtained without a need to use an expensive pulse generator. Micro-hole drilling carried out in a sodium nitrate aqueous solution with current pulse duration of 30ns showed that significantly small side gap of 2μm could be obtained.

Effect of electric current pulse type on springback, microstructure, texture, and mechanical properties during V-bending of AA2024 aluminum alloy

2020 ◽  
pp. 1-36
Author(s):  
Nafiseh Mohammadtabar ◽  
Mohammad Bakhshi-jooybari ◽  
Hamid Gorji ◽  
Roohollah Jamaati ◽  
Jerzy A. Szpunar
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electric Current ◽  
Current Pulse ◽  
Fiber Texture ◽  
Electric Current Pulse ◽  
Electric Pulses ◽  
Current Pulses ◽  
Electric Current Pulses ◽  
Pulse Type

Abstract The present work focused on the effect of the electric current pulse type on the springback, microstructure, texture, and mechanical properties during the V-bending process of AA2024 aluminum alloy. In order to investigate this effect, three different forming conditions including conventional V-bending and electrically assisted V-bending with square and sinusoidal pulses were considered. The results indicated that the amount of springback significantly decreased from 45.5° (for the sample formed via conventional V-bending) to 24° by applying the sinusoidal pulse. Microstructural observations revealed lower stored energy in the samples formed by electric current pulses which resulted in larger grain size compared to the samples formed without electric pulses. In addition, the result showed that the intensity of the (111)||BLD (bend line direction) fiber texture reduced after applying electric current pulses whereas it was very strong in the sample formed without electric pulses. It was suggested that the electric current pulses led to change the slip plane of the dislocations from {111} to {110} through cross slip. The applying electric current pulses decrease the ultimate tensile strength (UTS) from 471.1 MPa (for the conventional tensile test) to 448.0 and 426.7 MPa for the square and sinusoidal pulses, respectively. On the other hand, the electric pulses improved the formability of the AA2024 alloy owing to the activation of more slip systems, inhibition of dislocation pinning, the promotion of dislocation movement, and the acceleration of restoration mechanisms.

Sign in / Sign up

Export Citation Format

Share Document