scholarly journals Experimental studies of electrode coating thickness variation at pressing

2017 ◽  
Vol 2017 (1) ◽  
pp. 26-34
Author(s):  
A.E. Marchenko ◽  
Keyword(s):  
Coating Thickness ◽  
Experimental Studies ◽  
Thickness Variation ◽  
Electrode Coating

scholarly journals Evaluation of Coating Thickness Using Lift-Off Insensitivity of Eddy Current Sensor

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 419
Author(s):  
Xiaobai Meng ◽  
Mingyang Lu ◽  
Wuliang Yin ◽  
Abdeldjalil Bennecer ◽  
Katherine J. Kirk
Keyword(s):  
Eddy Current ◽  
Coating Thickness ◽  
Thickness Measurement ◽  
Eddy Current Testing ◽  
Thickness Variation ◽  
Testing Technique ◽  
Current Testing ◽  
Thin Skin ◽  
Embedded Algorithms ◽  
Lift Off

Defect detection in ferromagnetic substrates is often hampered by nonmagnetic coating thickness variation when using conventional eddy current testing technique. The lift-off distance between the sample and the sensor is one of the main obstacles for the thickness measurement of nonmagnetic coatings on ferromagnetic substrates when using the eddy current testing technique. Based on the eddy current thin-skin effect and the lift-off insensitive inductance (LII), a simplified iterative algorithm is proposed for reducing the lift-off variation effect using a multifrequency sensor. Compared to the previous techniques on compensating the lift-off error (e.g., the lift-off point of intersection) while retrieving the thickness, the simplified inductance algorithms avoid the computation burden of integration, which are used as embedded algorithms for the online retrieval of lift-offs via each frequency channel. The LII is determined by the dimension and geometry of the sensor, thus eliminating the need for empirical calibration. The method is validated by means of experimental measurements of the inductance of coatings with different materials and thicknesses on ferrous substrates (dual-phase alloy). The error of the calculated coating thickness has been controlled to within 3% for an extended lift-off range of up to 10 mm.

scholarly journals Evaluation of Coating Thickness Using Lift-Off Insensitivity of Eddy Current Sensor

2021 ◽  
Author(s):  
Xiaobai Meng ◽  
Mingyang Lu ◽  
Wuliang Yin ◽  
Abdeldjalil Bennecer ◽  
Katherine Kirk
Keyword(s):  
Eddy Current ◽  
Coating Thickness ◽  
Thickness Measurement ◽  
Eddy Current Testing ◽  
Thickness Variation ◽  
Testing Technique ◽  
Current Testing ◽  
Thin Skin ◽  
Embedded Algorithms ◽  
Lift Off

Defect detection in ferromagnetic substrates is often hampered by non-magnetic coating thickness variation when using conventional eddy current testing technique. The lift-off distance between the sample and the sensor is one of the main obstacles for the thickness measurement of non-magnetic coatings on ferromagnetic substrates when using the eddy current testing technique. Based on the eddy current thin-skin effect and the lift-off insensitive inductance (LII), a simplified iterative algorithm is proposed for reducing the lift-off variation effect using a multi-frequency sensor. Compared to the previous techniques on compensating the lift-off error (e.g., the lift-off point of intersection) while retrieving the thickness, the simplified inductance algorithms avoid the computation burden of integration, which are used as embedded algorithms for the online retrieval of lift-offs via each frequency channel. The LII is determined by the dimension and geometry of the sensor, thus eliminating the need for empirical calibration. The method is validated by means of experimental measurements of the inductance of coatings with different materials and thicknesses on ferrous substrates (dual-phase alloy). The error of the calculated coating thickness has been controlled to within 3 % for an extended lift-off range of up to 10 mm.

Directional Thickness Alteration of a Thin-Walled Ring Blank Using Flanging and Forming for the Purpose of Receiving Conical Part

2016 ◽  
Vol 684 ◽  
pp. 253-262 ◽  
Author(s):  
E.G. Demyanenko ◽  
I.P. Popov
Keyword(s):  
Experimental Studies ◽  
Thickness Variation ◽  
Conical Part ◽  
Flat Area ◽  
Minimal Thickness ◽  
Elastic Punch ◽  
Thin Walled ◽  
Ring Blank ◽  
Rigid Die

In this article the flanging method of thin-walled ring blanks using the elastic punch and rigid die scheme is investigated. Presence of a cylindrical portion near the larger edge and a flat area at the side of the blank hole is mandatory. Such conditions allow producing conical parts with minimal thickness variation by altering height of the cylindrical portion. Conducted experimental studies showed that the minimal thickness variation values are not exceeding 16% for different materials and relative thicknesses less than 0,01.

Effect of Stiff Coatings on EHL Film Thickness in Point Contacts

2007 ◽  
Author(s):  
Yuchuan Liu ◽  
Q. Jane Wang ◽  
Dong Zhu
Keyword(s):  
Film Thickness ◽  
Working Conditions ◽  
Coating Thickness ◽  
Point Contact ◽  
Thickness Variation ◽  
Point Contacts ◽  
Lubricant Film Thickness ◽  
Wide Range ◽  
Minimum Film Thickness ◽  
Coating Material Properties

This study investigates the influences of coating material properties and coating thickness on lubricant film thickness based on a point-contact isothermal EHL model developed recently by the authors. The results present the trend of minimum film thickness variation as a function of coating thickness and elastic modulus under a wide range of working conditions. Numerical results indicates that the increase in minimum film thickness, Imax, and the corresponding optimal dimensionless coating thickness, H2, can be expressed in the following formulas: Imax=0.766M0.0248R20.0296L0.1379exp(−0.0245ln2L)H2=0.049M0.4557R2−0.1722L0.7611exp(−0.0504ln2M−0.0921ln2L) These formulas can be used to estimate the effect of a coating on EHL film thickness.

Coating thickness variation during multistep drawing processes

2004 ◽  
Vol 39 (2) ◽  
pp. 757-760 ◽  
Author(s):  
L. Q. Zhou ◽  
Y. C. Zhou ◽  
Y. Pan
Keyword(s):  
Coating Thickness ◽  
Thickness Variation

scholarly journals Multi-frequency method of control for eddy current thickness measurement

2019 ◽  
Vol 64 (1) ◽  
pp. 118-126
Author(s):  
A. V. Chernyshev ◽  
I. E. Zagorskiy ◽  
V. I. Sharando
Keyword(s):  
Eddy Current ◽  
Coating Thickness ◽  
Control Method ◽  
Experimental Studies ◽  
Thickness Measurement ◽  
Coating Material ◽  
Electromagnetic Parameters ◽  
Specific Electric Conductivity ◽  
Frequency Method ◽  
Point To Point

When eddy-current thickness measurement is carried out, one of the disturbing factors leading to an error in determining the thickness of the conductive coating on a conducting ferromagnetic or non-ferromagnetic substrate are the variations of the electromagnetic parameters of the coating and the substrate observed when the transducer moves from point to point along the surface of the controlled product, when moving from one product to another, at presence of  heat treatment or other thermal effects on the controlled product after coating. The paper presents the results of experimental studies of the influence of variations in the electromagnetic parameters of a conducting ferromagnetic substrate on the phase of the emf, introduced into the superimposed transducer. It is shown, when the minimum influence of such variations on the specified phase is achieved. As a result, it was suggested to use the multi-frequency method to reduce the influence of variations of electromagnetic parameters on the accuracy of determining the coating thickness during application of the phase control method. It consists in the fact that the frequency of the excitation current of the transducer, mounted on the monitored product, is discretely reduced from a certain maximum to a certain minimum frequency during measurements. At the high frequency, the specific electric conductivity of the coating material is taken into account, with decreasing frequency, such a value is determined when the electromagnetic parameters of the substrate begin to affect the phase formation. Then, using the calibration curve obtained from samples from the same coating material and substrate as the controlled article and having a known coating thickness, the desired coating thickness on the product to be tested is determined.

Asperity Excited Temperature Field in a Coated Medium With a Random Uniform Coating Thickness

1989 ◽  
Vol 111 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Jew-Chyi Liu ◽  
F. D. Ju
Keyword(s):  
Temperature Field ◽  
Coating Thickness ◽  
Temperature Response ◽  
Mean Value ◽  
Thickness Variation ◽  
Thin Coating ◽  
Uniform Coating ◽  
Solid Media ◽  
The Mean ◽  
Statistical Space

The present paper investigates the random temperature response of a coated medium subjected to a fast moving asperity, taking into consideration the randomness of coating thickness. While the coating thickness is uniform for individual specimens, there is a small random variation from one specimen to another in a statistical space. Stochastic responses in coated solid media are investigated by the perturbation method, and the results are presented in terms of the mean value and the standard deviation of the temperature field. The numerical example considers a typical stochastic process. It is noted that even for very small thickness variation, for instances, the coefficient of the variation of coating thickness is 0.1 percent, the temperature at the interface for a thin coating can vary by a coefficient of variation of 18 percent.

scholarly journals An Investigation of Corrosion Progression Using Laser Profilometry

2020 ◽  
Author(s):  
Hong Zhang ◽  
Ruikun Wu
Keyword(s):  
Mild Steel ◽  
Early Stage ◽  
Low Cost ◽  
Experimental Studies ◽  
Thickness Variation ◽  
Non Destructive Evaluation ◽  
Laser Profilometry ◽  
Corrosion Science ◽  
The Relationship ◽  
Non Destructive

Atmospheric corrosion progression characterisation on metal substrates is a major problem in the field of corrosion science and Non-destructive Evaluation (NDE). A laser profilometry has been used to characterise the corrosion on the mild steel plate at a low cost and high resolution. Four mild steel samples have been measured which exposed to the marine environment from 1 month to 10 months. Two features have been developed to characterise thickness variation in the corrosion layer. These features have been used to characterise corrosion progression through experimental studies. The relationship between these features and corrosion progression has been derived which is useful for corrosion progression measurement, early-stage corrosion prediction, and monitoring areas.

Sign in / Sign up

Export Citation Format

Share Document