scholarly journals Shape Mapping Detection of Electric Vehicle Alloy Defects Based on Pulsed Eddy Current Rectangular Sensors

2018 ◽  
Vol 8 (11) ◽  
pp. 2066 ◽  
Author(s):  
Kai Zhang ◽  
Zhurong Dong ◽  
Zhan Yu ◽  
Yunze He
Keyword(s):  
Aluminum Alloy ◽  
Magnetic Flux ◽  
Electric Vehicle ◽  
Eddy Current ◽  
Comparison Of Results ◽  
Pulsed Eddy Current ◽  
Alloy Material ◽  
Plane Shape ◽  
Shape Mapping ◽  
Better Than

In this paper, we investigate pulsed eddy current (PEC) testing based on a rectangular sensor for the purpose of defect shape mapping in electric vehicle lightweight alloy material. Different dimensional defects were machined on the 3003 aluminum alloy and detected using the A-scan technique and C-scan imaging in two scanning directions. The experiment results indicated that defect plane shape could be preliminarily obtained and length and width could be estimated based upon C-scan contour images. Consequently, the comparison of results between the two directions showed that the C-scan identification in the direction of magnetic flux was better than in the direction of the exciting current. Finally, subsurface defects and irregular defects were detected to verify the performance of shape mapping as a recommended approach. The conclusion drawn indicates that the proposed method, based on PEC rectangular sensors, is an effective approach in reconstructing a defect’s shape.

Simultaneous measurement of thickness and lift-off using the tangential component of magnetic flux density in pulsed eddy current testing

2021 ◽  
Vol 63 (6) ◽  
pp. 341-347
Author(s):  
Hang Xu ◽  
Donglin Li ◽  
Tao Chen ◽  
Xiaochun Song
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Eddy Current ◽  
Tangential Component ◽  
Magnetic Flux Density ◽  
Logarithmic Scale ◽  
Time To Peak ◽  
Pulsed Eddy Current ◽  
Lift Off ◽  
Two Parameters

The pulsed eddy current (PEC) technique is commonly used in the petrochemical and power generation industries to measure two parameters: the degree of pipe wall corrosion and the thickness of the insulation shield. These two parameters can be evaluated by examining the thickness of conductive materials and the lift-off distance, respectively. To explore a possible technique for simultaneously measuring the thickness and the lift-off, the present study envisaged the development of a PEC testing method based on detecting the tangential component of the magnetic flux density. The tangential component of the magnetic flux density was excited by two racetrack-type coils injecting currents in opposite directions that were picked up by a magnetic sensor. The slope in logarithmic scale and the time-to-peak of the magnetic signal were verified to characterise the features of the thickness and the lift-off, respectively. By analysing the simulation and experimental results, the feasibility of simultaneously measuring the thickness and the lift-off was demonstrated.

scholarly journals Effect of vacuum system on porous product defects and micro structures on the ADC-12 aluminum material with cold chamber die casting machines

2021 ◽  
Vol 878 (1) ◽  
pp. 012072
Author(s):  
B Budiarto ◽  
T D Kurniawan
Keyword(s):  
Aluminum Alloy ◽  
Hot Spot ◽  
Die Casting ◽  
Casting Machine ◽  
Vacuum System ◽  
Magma Flow ◽  
Alloy Material ◽  
Cold Chamber ◽  
Better Than ◽  
Aluminum Material

Abstract Research on the effect of the vacuum system on porous product defects and microstructure on the ADC-12 aluminum alloy material with cold chamber die casting machine has been carried out. In the injection process in cold chamber die casting, the aluminum material commonly used is namely ADC-12. The ADC-12 aluminum alloy has better resistance to corrosion, is lightweight, has ease of casting, good mechanical properties, and dimensional stability. The purpose of this study is to compare the vacuum system with overflow system using ADC-12 aluminum alloy material with observed parameters are porosity, trapped air pressure, hot spot level, hardness level of Vickers Hardness, XRD analysis, and microstructure analysis with Light Optical Microscope (LOM). The results of the analysis using the Magma flow software, the vacuum system is better than the overflow system in terms of porosity and product yield, which is influenced by the amount of air trapped and the hot spot level. The level of hardness in a product with a vacuum system is better than a product with an overflow system. The average hardness in the vacuum system is 162,235 while in the overflow system is 147,615. Thus, the use of a vacuum system can increase the level of hardness in products by around 9%. With the change in usage from the overflow system to the vacuum system, it shows an increase in dislocation density followed by an increase in lattice strain and a decrease in the level of crystal size of the product.

scholarly journals Defect Classification Using Postpeak Value for Pulsed Eddy-Current Technique

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3390 ◽  
Author(s):  
Jiuhao Ge ◽  
Chenkai Yang ◽  
Ping Wang ◽  
Yongsheng Shi
Keyword(s):  
Defect Detection ◽  
Eddy Current ◽  
Surface Defect ◽  
Detection Experiment ◽  
Pulsed Eddy Current ◽  
Current Technique ◽  
Calculation Process ◽  
Surface Defect Detection ◽  
Better Than ◽  
Peak Value

In this paper, a feature termed as the postpeak value is proposed for the pulsed eddy current technique (PECT). Moreover, a method using the postpeak value is proposed to classify surface and reverse defects. A PECT system is built for verification purposes. Experiment results prove that the postpeak feature value has better performance than that of the traditional peak value in the case of reverse defect detection. In contrast, the peak value is better than the postpeak value in the case of surface defect detection. Experiment results also validate that the proposed classification algorithm has advantages: classification can be achieved in real time, the calculation process and results are easy to understand, and supervised training is unnecessary.

Quantitative Evaluation of Multi-Annular Downhole Corrosion Using Time-Domain Electromagnetic Measurements

2021 ◽  
Author(s):  
Sushant M. Dutta ◽  
Pervaiz Iqbal ◽  
Joseph Olaiya ◽  
Vladislav Danilenko
Keyword(s):  
High Resolution ◽  
Magnetic Flux ◽  
Case Studies ◽  
Quantitative Evaluation ◽  
Eddy Current ◽  
Eddy Currents ◽  
Magnetic Flux Leakage ◽  
Pulsed Eddy Current ◽  
New Instrument ◽  
Flux Leakage

Abstract A novel electromagnetic instrument is presented that uses transient or pulsed eddy current measurements to perform quantitative evaluation of downhole corrosion in four concentric tubulars individually, and to inspect a fifth tubular qualitatively. Case studies are presented that compare results from this instrument with industry-standard single-string evaluation tools such as multi-finger calipers and high-resolution magnetic flux leakage tools. The new instrument is based on transient or pulse eddy current technology and comprises three highly sensitive sensors that simultaneously achieve high-resolution of the inner barrier and high radial depth of investigation for up to five barriers. Each sensor induces coaxial rings of eddy currents in multiple concentric tubulars and measures a time-varying response from the outward-diffusing eddy currents. The full transient responses from multiple sensors are then interpreted to obtain individual tubular thickness profiles. Case studies are presented where the thickness profiles of outer barriers are obtained with the new instrument and are compared with high-resolution benchmark logs of multi-finger calipers and magnetic flux leakage tool. The benchmark logs were measured when the outer barrier was directly accessible because, either the inner barriers were not yet present, or the inner barriers were removed. These comparisons show that the new electromagnetic instrument is able to provide accurate individual tubular corrosion evaluation while logging through tubing. This ability is invaluable for proactive well integrity management because electrochemical corrosion, which is the primary corrosion mechanism in these wells, causes the outermost casing to fail first and then continues to penetrate inwards. Therefore, the new electromagnetic instrument enables early diagnosis of the outer tubulars to identify potential weak zones in the completion string while logging through tubing and eliminating the cost of pulling completions for this purpose. This paper describes the advantages and limitations of state-of-the-art multi-sensor pulsed eddy current measurements for individual barrier thicknesses of four or five strings. New case studies with high-resolution magnetic flux leakage tools and multi-finger calipers support these conclusions.

Analysis of field uniformity and quantitative evaluation of subsurface pitting corrosion in conductors via GPEC

2020 ◽  
Vol 64 (1-4) ◽  
pp. 19-29
Author(s):  
Shuting Ren ◽  
Yong Li ◽  
Bei Yan ◽  
Jinhua Hu ◽  
Ilham Mukriz Zainal Abidin ◽  
...  
Keyword(s):  
Quantitative Evaluation ◽  
Eddy Current ◽  
Pitting Corrosion ◽  
Gradient Field ◽  
Uniform Field ◽  
Eddy Current Method ◽  
Optimal Position ◽  
Pulsed Eddy Current ◽  
Field Uniformity ◽  
Processing Algorithms

Structures of nonmagnetic materials are broadly used in engineering fields such as aerospace, energy, etc. Due to corrosive and hostile environments, they are vulnerable to the Subsurface Pitting Corrosion (SPC) leading to structural failure. Therefore, it is imperative to conduct periodical inspection and comprehensive evaluation of SPC using reliable nondestructive evaluation techniques. Extended from the conventional Pulsed eddy current method (PEC), Gradient-field Pulsed Eddy Current technique (GPEC) has been proposed and found to be advantageous over PEC in terms of enhanced inspection sensitivity and accuracy in evaluation and imaging of subsurface defects in nonmagnetic conductors. In this paper two GPEC probes for uniform field excitation are intensively analyzed and compared. Their capabilities in SPC evaluation and imaging are explored through simulations and experiments. The optimal position for deployment of the magnetic field sensor is determined by scrutinizing the field uniformity and inspection sensitivity to SPC based on finite element simulations. After the optimal probe structure is chosen, quantitative evaluation and imaging of SPC are investigated. Signal/image processing algorithms for SPC evaluation are proposed. Through simulations and experiments, it has been found that the T-shaped probe together with the proposed processing algorithms is advantageous and preferable for profile recognition and depth evaluation of SPC.

Real-time wavelet denoising for pulsed eddy current signal based on heterogeneous dual-core

2013 ◽  
Vol 33 (3) ◽  
pp. 866-870
Author(s):  
Xuanbing QIU ◽  
Jilin WEI ◽  
Xiaochao CUI ◽  
Chunhua XIA
Keyword(s):  
Real Time ◽  
Eddy Current ◽  
Wavelet Denoising ◽  
Current Signal ◽  
Pulsed Eddy Current ◽  
Dual Core
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