scholarly journals Support with mechanical vibrations of welding processes ‒ review of own research

2021 ◽  
Vol 93 (3) ◽  
pp. 57-73
Author(s):  
Arkadiusz Krajewski ◽  
Paweł Kołodziejczak ◽  
Paweł Cegielski ◽  
Jarosław Grześ
Keyword(s):  
Aluminum Alloys ◽  
Comparative Research ◽  
Low Frequency ◽  
Diffusion Welding ◽  
Ultrasonic Frequency ◽  
Shot Blasting ◽  
Mechanical Vibrations ◽  
Grain Sizes ◽  
Welding Processes ◽  
Vibrating Systems

The article discusses the most important original achievements in the use of high-power mechanical vibrations with low and ultrasonic frequency in various welding processes such as MIG, MAG, TIG, RW, LW, diffusion welding and brazing in relation to various basic materials such as structural steel and aluminum alloys. Mechanical vibrations were introduced by means of ultrasonic vibrating systems and using the shot-blasting process, as well as acoustic influence. As part of the comparative research, the structure and hardness analysis of HV0.1 was presented. The obtained results indicate that both low-frequency and ultrasonic frequency vibrations significantly change the properties of the resulting structures affected by mechanical vibrations. The scale of these changes varies depending on the frequency and parameters specific to each of the welding processes used. The obtained results allow us to conclude that the skillful application of mechanical vibrations accompanying welding processes can contribute to the reduction of grain sizes, to change the depth or width of penetration and to lowering hardness in the sensitive heat affected zone area.

scholarly journals Impact of mechanical vibrations introduced by up blasting on the structure and hardness of welds on P235GH steel during MAG welding process

2020 ◽  
Vol 91 (12) ◽  
pp. 25-32
Author(s):  
Arkadiusz Krajewski ◽  
Paweł Kołodziejczak ◽  
Xiaoming Wang
Keyword(s):  
Base Material ◽  
Welding Process ◽  
Parent Material ◽  
Mag Welding ◽  
Shot Blasting ◽  
Mechanical Vibrations ◽  
Vibrating System ◽  
Rigid Attachment ◽  
Comparative Results ◽  
Welding Processes

This article discusses the effects of surfacing with the introduction of mechanical vibrations into the material using shot blasting. It does not require a rigid attachment of the vibrating system to the base material, and vibrations are introduced as a result of supplying energy of collision of the shot with the parent material. The effect of introducing mechanical vibrations through shot blasting during welding of P235GH steel on the structure and hardness of obtained structures was described. Comparative results of tests revealing the basic differences in the structural structure and hardness of reached welds without shot blasting and with its participation were presented. As a result of the conducted research, differences in the structural structure of the welds were shown and it was shown that shot blasting is an effective and alternative method of introducing mechanical vibrations supporting welding processes.

Optimization of Chlorella pyrenoidosa Removal by Low Frequency Ultrasonic Irradiation Using Response Surface Design

2011 ◽  
Vol 295-297 ◽  
pp. 1860-1865 ◽  
Author(s):  
Zhi Zhang ◽  
Chao Liu ◽  
Gong Duan Fan ◽  
Jing Luo ◽  
Yan Dong Wang
Keyword(s):  
Response Surface ◽  
Irradiation Time ◽  
Removal Rate ◽  
Low Frequency ◽  
Chlorella Pyrenoidosa ◽  
Ultrasonic Frequency ◽  
Ultrasonic Power ◽  
Control Parameters ◽  
Single Factor ◽  
Surface Design

The control parameters of the removal of Chlorella pyrenoidosa, which was irradiated by low frequency ultrasonic, is optimized by using single factor experiments and response surface methodology (RSM). First of all, the approximate ranges of the ultrasonic frequency, the ultrasonic power and the irradiation time were estimated with single factor experiments for the further experiments. And then the optimized values of the three control parameters were determined, which were analyzed by using central composite design (CCD) and RSM. The results showed that the removal rate of chlorophyll-a could reach to 64.1% after the irradiation for 6.34min by using ultrasonic of 77.7 kHz and 250W. Ultrasonic technology can remove Chlorella pyrenoidosa cells in water quickly and effectively, so as to achieve the purpose of water purification.

Effect of mechanical vibrations of ultrasonic frequency on the structure of St. 45 steel

1972 ◽  
Vol 5 (1) ◽  
pp. 86-88
Author(s):  
N. L. Pozen ◽  
V. N. Semirog-Orlik ◽  
I. A. Troyan
Keyword(s):  
Ultrasonic Frequency ◽  
Mechanical Vibrations

Evaluation of dissimilar joints properties of 5083-H12 and 6061-T6 aluminum alloys produced by tungsten inert gas and friction stir welding

2015 ◽  
Vol 231 (3) ◽  
pp. 297-308 ◽  
Author(s):  
Morteza Ghaffarpour ◽  
Mohammad Kazemi ◽  
Mohammad Javad Mohammadi Sefat ◽  
Ahmad Aziz ◽  
Kamran Dehghani
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Traverse Speed ◽  
Inert Gas ◽  
Dissimilar Joints ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys ◽  
The Difference ◽  
Welding Processes

In the present study, friction stir welding (FSW) and tungsten inert gas (TIG) techniques were used to join the dissimilar aluminum alloys of 5083-H12 and 6061-T6. The laboratory tests were designed using design of experiment (DOE) method. Variables for the FSW process were the rotational speed, traverse speed, shoulder diameter, and pin diameter. They changed in ranges of 700–2500 r/min, 25–400 mm/min, 10–14 mm, and 2–4 mm, respectively. In the case of TIG process, the variables were current intensity, traverse speed, and tilt angle. These parameters varied from 80 to 90 A, 200 to 400 mm/min, and 3° to 12°, respectively. The optimum amounts of parameters were obtained using response surface methodology (RSM). The RSM-based model was developed to predict ultimate tensile strength (UTS) of the welds produced. In FSW, the difference between predicted and measured UTS was about 1.28% and in TIG it was 1.78%. The good agreement between experimental and predicted results indicates the high accuracy of the developed model. Mechanical properties and also the microstructure of the welds were compared after optimizing both welding processes using RSM. The results showed that the welds produced by FSW indicated a considerably higher quality and also improved mechanical properties compared to TIG. Properties of the joints obtained by FSW in single-sided joints were more desirable. In the double-sided welds obtained by FSW these differences were of an even higher significance.

A Study of the Response of a Small Porous Chamber to Forced Oscillation

1966 ◽  
Vol 88 (1) ◽  
pp. 25-32
Author(s):  
R. L. Peskin ◽  
E. Martinez
Keyword(s):  
Phase Angle ◽  
High Frequency ◽  
Gas Flow ◽  
Low Frequency ◽  
Pressure Change ◽  
Analytical Investigation ◽  
Frequency Curve ◽  
Cylindrical Chamber ◽  
Gas Damping ◽  
Vibrating Systems

An analytical investigation of the pressure response to forced volume oscillations of a shallow cylindrical chamber with a porous end is undertaken. Investigation is in the frequency domain. Both infinite and finite-length chambers are considered. The irreversible gas flow introduces a frequency-dependent phase angle between volume and pressure change. Pressure leads volume at low frequency, and the phase angle becomes zero at high frequency. Curve characteristics suggest applications such as gas damping of vibrating systems.

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