Improving of Energy Density in Welding Arc and its Mechanism Study

2013 ◽  
Vol 711 ◽  
pp. 229-234 ◽  
Author(s):  
Tian Jiao Xiao ◽  
Yong Lun Song ◽  
Qiu Shi Hu ◽  
Chao Li
Keyword(s):  
Energy Density ◽  
Arc Discharge ◽  
Pulse Frequency ◽  
Inert Gas ◽  
Input Energy ◽  
Mechanism Study ◽  
Pulse Input ◽  
Welding Arc ◽  
Ionization Region ◽  
Contraction Effect

As to traditional single electrode free welding arc, changes about energy density of the ionizing region in the center of arc column is not obvious with current increases due to structural limitations. In this paper, we developed parallel multi-electrode arc discharge torch which is based on the mechanism of self-magnetic contraction effect in welding arc, the torch effectively improve energy density of ionization region in non-melting inert gas arc, which is proved by experiments, and we discussed, effect of the pulse input energy and pulse frequency to energy density of the arc with parallel multi-electrode torch. This study demonstrated the approach of improving the energy density of arc ionizing region by self-magnetic pinch effect is feasible.

scholarly journals Comprehensive Effect of Arc and Ultrasonic Energy on MIG Arc Ultrasonic Welding

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4884
Author(s):  
Qihao Chen ◽  
Chengcheng Wang ◽  
Yihao Wang ◽  
Jiahui Wang ◽  
Sanbao Lin ◽  
...  
Keyword(s):  
Energy Density ◽  
High Speed ◽  
Weld Zone ◽  
Ultrasonic Energy ◽  
Second Phase ◽  
Ultrasonic Frequency ◽  
Excitation Voltage ◽  
Welding Arc ◽  
Arc Shape ◽  
Frequency Current

Ultrasonic energy is introduced into the Metal Inert Gas (MIG) welding arc and weld pool by superposition of an ultrasonic frequency current. In this study, the arc shape, arc energy, and ultrasonic energy that responded to ultrasonic excitation voltage and frequency is investigated. The comprehensive influence of arc and ultrasonic energy on weld formation, microstructure, and mechanical properties is further studied. The arc and ultrasonic energy are analyzed by using a high-speed camera and microphone, respectively. The results showed that the arc width increased, and the arc energy density decreased after the superposition of ultrasonic current. The arc height could be compressed under certain ultrasonic excitation parameters. The ultrasonic excitation voltage and frequency had a direct influence on the ultrasonic energy. The arc height, arc energy density, and ultrasonic energy together determined the weld width. Ultrasound could effectively refine the microstructure of the weld zone and fusion zone but had little effect on the heat-affected zone. Ultrasound improved the hardness of the joint by refining the grain and the second phase. The joint hardness was the highest when the ultrasonic excitation voltage was 100 V, and the frequency was 30 kHz.

Influence of Pulse Frequency on Mullite Coatings Prepared by Pulse Arc Discharge Deposition Process and Activation Energy

2014 ◽  
Vol 809-810 ◽  
pp. 635-641
Author(s):  
Bo Zhang ◽  
Jian Feng Huang ◽  
Cui Yan Li ◽  
Li Yun Cao ◽  
Hai Bo Ouyang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Arc Discharge ◽  
Deposition Process ◽  
Pulse Frequency ◽  
Deposition Kinetics ◽  
Mullite Phase ◽  
Mullite Coatings ◽  
Sic Composites ◽  
Mullite Powder ◽  
Source Materials

Mullite coatings were prepared on C/C-SiC composites surface by pulse arc discharge deposition using mullite powder as source materials. Phase composites and microstructures of the as-prepared mullite coatings were characterized by XRD and SEM. Deposition kinetics and influence of pulse frequency on the phase composites and microstructures were investigated. The results indicate that the outer layer is composed of mullite phase, density and homogeneity of the mullite coatings are achieved when the pulse frequency reaches 2000 Hz. The deposition amount of the mullite coatings also increases with increasing deposition temperature. The deposition mass of the coatings and the square root of the deposition time at different deposition temperatures according to linear relationship, and the deposition activation energy is calculated to be 32.24 kJ/mol.

scholarly journals Experimental Investigation on the Energy Storage Characteristics of Red Sandstone in Triaxial Compression Tests with Constant Confining Pressure

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Liuliu Li ◽  
Fengqiang Gong
Keyword(s):  
Energy Density ◽  
Elastic Energy ◽  
Quadratic Function ◽  
Input Energy ◽  
Compression Tests ◽  
Red Sandstone ◽  
Elastic Energy Density ◽  
Deep Rock ◽  
Confining Pressures ◽  
Input Energy Density

The elastic energy stored in deep rock in three-dimensional stress environment is the energy source of rockburst. To investigate the energy storage characteristics of deep rock under different confining pressures, a series of triaxial single-cyclic loading-unloading compression tests were conducted on red sandstone specimens under eight confining pressures. The input energy density, elastic energy density, and dissipative energy density of the specimen in axial, circumferential, and total directions can be obtained by the area diagram integration method. The results show that the input energy density in the axial direction accounts for the largest logarithmic proportion of the total input energy density, and the relationship between all energy density parameters and unloading level can be described by quadratic function. In the axial direction, there is a linear function relationship among elastic energy density, dissipative energy density, and input energy density. In the circumferential direction, there is a quadratic function relationship among elastic energy density, dissipative energy density, and input energy density. For the total energy density parameters of the rock specimen, the relationship among elastic energy density, dissipative energy density, and input energy density conforms to the quadratic function. According to the above correlation function, the elastic energy stored in deep rock under different confining pressures can be accurately obtained, which provides a foundation for studying the mechanism of rockburst under three-dimensional unloading from the energy perspective.

Solar-energy liberation from water by electric arcs

1998 ◽  
Vol 60 (4) ◽  
pp. 775-786 ◽  
Author(s):  
GEORGE HATHAWAY ◽  
PETER GRANEAU ◽  
NEAL GRANEAU
Keyword(s):  
Kinetic Energy ◽  
Energy Input ◽  
Arc Discharge ◽  
Heat Losses ◽  
Energy Liberation ◽  
Input Energy ◽  
External Energy ◽  
Photographic Evidence ◽  
Energy Cycle ◽  
The Difference

This paper reports progress in an experimental investigation, started in the Hathaway laboratory in 1994, dealing with the liberation of intermolecular bond energy from ordinary water by means of an arc discharge. Photographic evidence of fog generation and explosion during the arcing period is included. A new fog accelerator is described and a table of results of the kinetic energies of fog jets is provided. A renewable water energy cycle is outlined. The fog kinetic energy has been found to be greater than the difference between the capacitor input energy and the heat losses. Given energy conservation, the only external energy input that can account for the fog kinetic energy is solar heat from the atmosphere.

Selective Laser Melting Bone-Compatible Pure Titanium Porous Structure

2013 ◽  
Vol 423-426 ◽  
pp. 833-836
Author(s):  
Zi Fu Li ◽  
Chun Yu Zhang ◽  
Liu Ju Qi ◽  
Xue Tong Sun
Keyword(s):  
Energy Density ◽  
Porous Structure ◽  
Selective Laser Melting ◽  
Pure Titanium ◽  
High Strength ◽  
Input Energy ◽  
Densification Behavior ◽  
Laser Melting ◽  
Commercially Pure ◽  
Input Energy Density

In this paper the effect of selective laser melting (SLM) input energy density on densification behavior and tensile strengths of commercially pure (CP) titanium was investigated. Fully dense and high strength SLM CP titanium has been obtained. A complex bone-compatible tetrakaidecahedron based porous structure has been successfully SLM-fabricated with optimized laser parameters.

A mathematical model for fluid flow in a weld pool at high currents

1980 ◽  
Vol 98 (4) ◽  
pp. 787-801 ◽  
Author(s):  
D. R. Atthey
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Weld Pool ◽  
Fluid Motion ◽  
Reynolds Numbers ◽  
Time Dependent ◽  
Inert Gas ◽  
Low Reynolds Numbers ◽  
Welding Arc ◽  
Time Dependent Problem

In order to determine the heat transfer inside a TIG (tungsten/inert gas) weld pool, it is necessary to have a good understanding of the flow patterns of the liquid metal. The principal force driving the fluid motion is the electromagnetic j × B force due to the current from the welding arc and its self-magnetic field. In this paper we consider the flow of a viscous incompressible conducting fluid in a hemispherical container due to various distributions of the electric current. The problem is posed as a time-dependent problem and is solved numerically using the Du Fort–Frankel leap-frog method. Results are presented for currents of 100 A flowing through the weld pool. This is a typical current for TIG welding, and corresponds to a Reynolds number in the range 200 < Re < 600. Previous solutions of the problem were restricted to low Reynolds numbers, i.e. low currents.

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