Behavior of Exit Keyhole Diameter during Switch off Period in Plasma Keyhole Arc Welding

2018 ◽  
Vol 26 ◽  
pp. 87-92
Author(s):  
Anh Nguyen Van ◽  
Tashiro Shinichi ◽  
Huu Manh Ngo ◽  
Akihisa Murata ◽  
Tadasuke Murata ◽  
...  
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
High Speed ◽  
Video Camera ◽  
High Speed Video ◽  
High Speed Video Camera

The purpose of this investigation is to clarify the behavior of exit keyhole diameter during switch off (cutting arc) period in case of Plasma keyhole arc welding (PKAW). During switch off period, the keyhole and weld pool are visualized from backside via a high speed video camera (HSVC). The result showed that keyhole diameter on the backside is unstable. The keyhole size is much changed in X-axis. Firstly, it is increased and then it is decreased to a stationary value at t = 0.05 s after cutting arc. Meanwhile, the size in Y-axis is not changed approximately from t = 0.01 s after cutting arc. The results can be considered to control this process more efficiency.

scholarly journals Interactive Phenomena in Hybrid KPAW–GMAW-P

2020 ◽  
Vol 99 (05) ◽  
pp. 146s-155s
Author(s):  
DONGSHENG WU ◽  
◽  
SHINICHI TASHIRO ◽  
ZIANG WU ◽  
MANABU TANAKA ◽  
...  
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Video Camera ◽  
Plasma Arc ◽  
Tungsten Electrode ◽  
Current Path ◽  
Metal Arc Welding ◽  
High Speed Video Camera

A hybrid welding technique formed by combining keyhole plasma arc welding (KPAW) and pulsed gas metal arc welding (GMAW-P) is characterized by the complex interactions of the arc, droplet, keyhole, and weld pool. With the help of a high-speed video camera, zirconia particles, and a thermal camera, the complex interactive phenomena of the hybrid KPAW–GMAW-P process was analyzed. Owing to the formation of a direct-current path between the KPAW cathode (tungsten electrode) and the GMAW anode (welding wire), the ionized plasma arc was extended to the GMA side, causing an expansion of the GMA. The current at the GMAW droplet was diverged; thus, the Lorentz force promoted a more stable one pulse one droplet metal transfer mode compared with that of GMAW-P. The strong backward flow from the keyhole was suppressed because of the pull-push flow pattern on the top surface of the weld pool be-tween the two arcs. As the heat and molten metal in the weld pool were transported from the region near the GMA (high temperature) to the region near the plasma arc (low temperature), the weld pool temperature decreased.

Study on Magnetic Barrel Machine Equipped with Three-Dimensional Arrangement of Magnets

2007 ◽  
Vol 329 ◽  
pp. 761-766 ◽  
Author(s):  
Y. Zhang ◽  
Masato Yoshioka ◽  
Shin-Ichiro Hira
Keyword(s):  
High Speed ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Video Camera ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
The Media ◽  
Set Up

At present, a commercially available magnetic barrel machine equipped with permanent magnets has some faults arising from constructional reason. That is, grinding or finishing ability is different from place to place in the machining region, resulting in the limitation on the region we can use in the container of workpieces. Therefore, in this research, authors made the new magnetic barrel machine equipped with three dimensional (3D) magnet arrangement to overcome these faults. The grinding ability of the new 3D magnetic barrel machine converted was experimentally examined, and compared with that of the traditional magnetic barrel machine. As a result, it was shown that we can use much broader region in the new 3D machine. It was also shown that the grinding ability became higher. The distribution of barrel media in action was recorded by means of a high speed video camera. It was clarified that the media rose up higher and were distributed more uniformly in the container by the effect of the magnet block newly set up. It was supposed that this must be the reason for the above-mentioned improvement of grinding ability.

Grease soap particles passing through an elastohydrodynamic contact under side slip conditions

2000 ◽  
Vol 214 (4) ◽  
pp. 317-325 ◽  
Author(s):  
P Eriksson ◽  
V Wikström ◽  
R Larsson
Keyword(s):  
Film Thickness ◽  
High Speed ◽  
Previous Investigation ◽  
Video Camera ◽  
Slip Conditions ◽  
High Speed Video ◽  
Elastohydrodynamic Contact ◽  
High Speed Video Camera ◽  
Pure Rolling ◽  
Minimum Film Thickness

In a previous investigation, grease thickener fibres were tracked as they passed through an elastohydrodynamic (EHD) contact in pure rolling using interferometry in a standard ball-and-disc apparatus. In order to capture single thickener fibres, a high-speed video camera was used. Here, the experiments have been repeated introducing different amounts of side slip for different rolling speeds and a faster video camera capable of capturing 4500 frames/s. The contact was lubricated with a continuous supply of grease. Two greases, based on the same synthetic poly(α-olefin) but thickened with Li-12-OH and lithium complex soap respectively, were studied. It was observed that the thickener fibres were stretched both before entering the contact and as they passed through it. Fibres seem to avoid the minimum film thickness regions and, if they enter, the film is restored immediately after passage.

Biomechanical Analysis of a World Record Javelin Throw: A Case Study

1985 ◽  
Vol 1 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Robert J. Gregor ◽  
Marilyn Pink
Keyword(s):  
High Speed ◽  
Video Camera ◽  
The United States ◽  
Track And Field ◽  
Biomechanical Analysis ◽  
World Record ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Ongoing Project

As part of an ongoing project to evaluate elite track and field throwers in the United States, the javelin competition was filmed during the 1983 Pepsi Invitational Track Meet. A high-speed video camera (Spin Physics SP2000) was positioned orthogonal to the javelin runway to record the release of all throws. During this competition, Tom Petranoff’s world record (99.72 m) was filmed at 200 fields per second. Subsequent frame-by-frame digitization yielded results consistent with reports in the literature. Release velocity was 32.3 m/s and represents one of the highest values ever reported. Angle of release was .57r, javelin attitude at release was .64r» and angle of attack was .07r. While optimum values for these release parameters, in light of published results, remain open to discussion, the results presented here represent unique information on a world record performance and can serve as a basis of comparison for future performances.

scholarly journals Investigation of laser consolidation process for metal powder by two-color pyrometer and high-speed video camera

CIRP Annals ◽  
2013 ◽  
Vol 62 (1) ◽  
pp. 223-226 ◽  
Author(s):  
Tatsuaki Furumoto ◽  
Takashi Ueda ◽  
Mohd Rizal Alkahari ◽  
Akira Hosokawa
Keyword(s):  
Metal Powder ◽  
High Speed ◽  
Video Camera ◽  
Consolidation Process ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Color Pyrometer

Visualization of Flow-Field between the Flapper and Nozzle in a Hydraulic Servo-Valve

2011 ◽  
Vol 402 ◽  
pp. 407-411 ◽  
Author(s):  
Jacob M. Mchenya ◽  
Sheng Zhuo Zhang ◽  
Song Jing Li
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Video Camera ◽  
Computer Assisted ◽  
Servo Valve ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Hydraulic Servo ◽  
Working Principle ◽  
Computer Assisted Image

In order to understand the mechanism and get rid of the high-frequency self-excited noise in a hydraulic servo-valve, in this paper, the flow field distribution in the pilot stage of a hydraulic flapper-nozzle servo-valve is investigated. An assembly is prepared representing the construction and working principle of the flow field inside the pilot stage of a hydraulic flapper-nozzle servo-valve. A method of visualization is developed by taking videos for the flow field inside the transparent assembly with a high speed video camera. In this study, at different inlet pressure the high speed video camera was utilized for flow visualization together with computer-assisted image measurement. The shape of the jet flow, the cavitations and vortex flow inside the flow field can be visualized clearly. The proposed method enables to analyze the flow-field in the pilot stage of a hydraulic flapper-nozzle servo-valve by giving useful information for better design.

scholarly journals Thermocapillary rupture of a horizontal liquid layer on a silicon substrate

2019 ◽  
Vol 196 ◽  
pp. 00041
Author(s):  
Dmitry Kochkin ◽  
Valentin Belosludtsev ◽  
Veronica Sulyaeva
Keyword(s):  
Experimental Study ◽  
Contact Line ◽  
High Speed ◽  
Video Camera ◽  
Phase Contact ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Three Phase ◽  
Breakdown Phenomenon ◽  
Dry Spot

This paper is an experimental study of thermocapillary breakdown phenomenon in a horizontal film of liquid placed on a silicon nonisothermal substrate. With the help of a high-speed video camera the speed of the three-phase contact line was measured during the growth of a dry spot.

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