scholarly journals Research on the welded seams of aluminum alloys using super-miniature eddy current transducers

2018 ◽  
Vol 212 ◽  
pp. 01001
Author(s):  
Sergey Dmitriev ◽  
Vladimir Malikov ◽  
Anatoly Sagalakov
Keyword(s):  
Eddy Current ◽  
Cutoff Frequency ◽  
Technical Information ◽  
Measurement Procedure ◽  
Measuring System ◽  
Friction Stir ◽  
Current Converter ◽  
Transformer Type ◽  
Aluminum Plates ◽  
Welded Seam

Based on the eddy current transducer of the transformer type, a measuring system has been developed that makes it possible to investigate the welded joints obtained by friction stir welding (FSW). The main technical information about the eddy current converter being used is given, and a measurement procedure is described that allows to search for defects in welded seams of aluminum plates. The device allows to automatically change the main operating frequency of the device and the cutoff frequency of the filtration system. The experiments were carried out on aluminum-magnesium alloy plates being connected by friction welding. In the article, the results of measurements are presented, allowing to estimate the quality of a welded seam and to answer a question on reliability of welding.

scholarly journals Scanning the Welded Seams of Titanium Alloys by Using Subminiature Eddy Current Transducers

2017 ◽  
Vol 906 ◽  
pp. 147-152 ◽  
Author(s):  
S. Dmitriev ◽  
A. Ishkov ◽  
Vladimir Malikov ◽  
A. Sagalakov
Keyword(s):  
Titanium Alloys ◽  
Eddy Current ◽  
Cutoff Frequency ◽  
Technical Information ◽  
Measurement Procedure ◽  
Current Transformer ◽  
Measuring System ◽  
Current Transformers ◽  
Transformer Type

The eddy current transformer (EST) of the transformer type is used to construct a sensor for investigating titanium sheets joined by a welded joint. The article provides the key technical information about the eddy current transformer used and describes the methodology of measurements that makes it possible to control defects in the welding seams of titanium alloys. It is capable of automatically changing the filtering cutoff frequency and operating frequency of the device. The designed measuring system eliminates the main drawback of eddy current transformers (the small area of the electromagnetic field), simultaneously significantly reducing the noise level due to the use of high-quality amplifiers and filters, and searches for defects in and alloys of different metals. A measurement procedure that allows one to perform high-accuracy monitoring of flaws in different alloys is described. Experiments were conducted on welded BT1-0 titanium plates. The article contains the results of these measurements. The dependence data facilitates the assessment of the quality of welding seams and helps make an educated conclusion about welding quality.

Superminiature Eddy-Current Transducers for Studying Steel to Dielectric Junctions

2018 ◽  
Vol 927 ◽  
pp. 161-167 ◽  
Author(s):  
S. Dmitriev ◽  
A. Ishkov ◽  
Vladimir Malikov ◽  
A. Sagalakov ◽  
Lilia Shevtsova
Keyword(s):  
Eddy Current ◽  
Voltage Drop ◽  
Experimental Studies ◽  
Technical Information ◽  
Current Transformer ◽  
Electric Steel ◽  
Induced Voltage ◽  
Operating Life ◽  
Software Complex ◽  
Current Converter

We applied eddy current transducer (ECT) to examine the electric steel parameters. The research topic is considered relevant due to the need for evaluation and forecasting of safe operating life of electric steel products. A scheme that uses a computer as a generator and receiver of signals from windings is proposed. Having the designed transducer as a basis, a hardware-software complex was built to perform experimental studies of steel at the interface boundary. The article provides the key technical information about the eddy current transformer used and describes the methodology of measurements that makes it possible to control steel to dielectric transition. Test results are reported for a specimen with continuous and discrete measurements taken at different frequencies. The curve of introduced voltage amplitude as a function of sensor location was constructed to study in details the introduced voltage drop at the ferromagnetic-dielectric interface. Presentation of induced voltage changes in the form of mathematical dependences enables to elicit the ways of interaction between electromagnetic field of eddy-current converter and residual magnetic field of steel.

scholarly journals Scanning the welded joints of aluminium alloys using subminiature eddy-current transducers

2018 ◽  
Vol 33 ◽  
pp. 02054
Author(s):  
Sergey Dmitriev ◽  
Alexey Ishkov ◽  
Vladimir Malikov ◽  
Anatoly Sagalakov
Keyword(s):  
Friction Stir Welding ◽  
Eddy Current ◽  
Welded Joints ◽  
Ease Of Use ◽  
Measuring System ◽  
Safety Requirements ◽  
Friction Stir ◽  
High Rise ◽  
Strength And Durability ◽  
Eddy Current Transducer

Aluminium has a reputation for ease of use, strength and durability. In addition to its exceptional aesthetic properties, solid aluminium does not burn. As architects, contractors, consultants and real estate owners look to meet stringent safety requirements in the construction and refurbishment of high-rise constructions for both residential and commercial uses, aluminium cladding provides an alternative that is not only safe but that is also durable and attractive. One of the ways to connect elements into a aluminium construction is welding. friction stir welding is one of the most efficient. The authors developed a measuring system based on subminiaturized eddy-current transducers aimed at examining locally the defects of welded joints in aluminium-magnesium alloy plates connected by means of friction stir welding. The authors made a modification of the Delyann filter, which allowed them to increase considerably the signal-noise relations. The dependency of the eddy-current transducer response on defects was provided, i.e. concealed cuts and openings inside the welded joint, at the frequencies of 100-10000 Hz of the exciting winding.

scholarly journals Research of thickness by using subminiature eddy-current transducers

2018 ◽  
Vol 226 ◽  
pp. 04017
Author(s):  
Sergey F. Dmitriev ◽  
Vladimir N. Malikov ◽  
Anatoly M. Sagalakov
Keyword(s):  
Eddy Current ◽  
Measurement Techniques ◽  
Current Method ◽  
Dielectric Coating ◽  
Measuring System ◽  
Eddy Current Method ◽  
Dielectric Coatings ◽  
Current Transducer ◽  
Transformer Type ◽  
Eddy Current Transducer

On the basis of an eddy-current transducer of a transformer type, a measuring system is made, which makes it possible to estimate the possibility of using the eddy current method for measuring the thickness of conductive and dielectric coatings placed on a conductive base. The purpose of this work was to evaluate the possibility of using only an amplitude eddycurrent method for determining the thickness of a conductive or dielectric coating on a conductive base and estimating the error of such measurements. The design of the measuring system and measurement techniques is described. The article presents data demonstrating the dependence of the amplitude part of the signal on objects of different thicknesses; limiting object dimensions at which these measurements are expedient are experimentally established.

Calculation method of winding eddy‐current losses for high‐voltage direct current converter transformers

2016 ◽  
Vol 10 (6) ◽  
pp. 488-497 ◽  
Author(s):  
Yaqing Liu ◽  
Dandan Zhang ◽  
Zhenbiao Li ◽  
Qinqing Huang ◽  
Bin Li ◽  
...  
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Eddy Current ◽  
Calculation Method ◽  
Eddy Current Losses ◽  
High Voltage Direct Current ◽  
Current Converter

Surface Smoothing of A5083 Aluminum Alloy Plate by Friction Stir Forming

2019 ◽  
Vol 803 ◽  
pp. 50-54
Author(s):  
Takahiro Ohashi ◽  
Kento Okuda ◽  
Hamed Mofidi Tabatabaei ◽  
Tadashi Nishihara
Keyword(s):  
Aluminum Alloy ◽  
Feed Rate ◽  
Metal Plate ◽  
Spindle Speed ◽  
Back Surface ◽  
Alloy Plate ◽  
Friction Stir ◽  
Shoulder Diameter ◽  
Aluminum Alloy Plate ◽  
Aluminum Plates

This paper provides a framework for the transcription of the surface of a mirror-finished die onto a metal plate by friction stir forming (FSF). In FSF, a material is put on a die, then friction stirring was conducted on its back surface for the transcription of the profile of the die onto the material. In this paper, a mirror-polished die of JIS SUS304 stainless steel with surface roughness Sz 0.014 mm and a probe-less friction-stirring tool in 18 mm shoulder diameter were employed for the experiment. A5083P-O aluminum plates, 3 mm thick, were utilized as base metals for the transcription. The authors varied tool spindle speed and tool feed rate to evaluate the forming results. Consequently, a mirror-finished surface under the friction-stirring tool was successfully transferred from the die to the aluminum alloy plate. The roughness of the base metal before processing was Sz 0.022 mm and that of the processed metal was Sz 0.012–0.016 mm. Higher spindle speed and faster feed rate resulted in a smoother surface; it is thought that high spindle speed and faster feed rate should be effective for higher contact pressure between a die and a material.

Temperature Distribution of Aluminum Alloys under Friction Stir Welding

2011 ◽  
Vol 264-265 ◽  
pp. 217-222 ◽  
Author(s):  
Ben Yuan Lin ◽  
P. Yuan ◽  
Ju Jen Liu
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Cross Section ◽  
Base Material ◽  
Welding Process ◽  
Measuring System ◽  
Close Correspondence ◽  
Distribution Profile ◽  
Butt Welding ◽  
Friction Stir

The temperature distribution of 6061-T6 aluminum alloy plates under a friction stir butt-welding was investigated by using experiment and numerical simulation. A real-time temperature measuring system was used to measure the temperature change in the welding process. Vickers hardness profiles were made on the cross-section of the weld after welding. A commercial software of FlexPDE, a solver for partial different equations with finite element method, was used to simulate the experimental welding process of this study. Comparison the experimental and numerical results, the temperature cycles calculated by numerical are similar to those measured by experiment. The temperature distribution profile obtained from the numerical simulation is symmetrical to the weld center and has a close correspondence with the hardness configuration and the microstructure of the weld. The region with the temperature over 300 °C is the zone of softening within the boundaries of base material and HAZ. The regions of 350 °C with minimum hardness are located near the boundary of HAZ and TMAZ. The maxima temperature about 500 °C distributes around the upper part of the weld center. However, the region above 400 °C only matches with the upper half of the weld nugget.

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