A laser reflectometry technique for on-device coating thickness measurements

2010 ◽  
Author(s):  
Stephen J. Morris
Keyword(s):  
Coating Thickness ◽  
Thickness Measurements ◽  
Laser Reflectometry

X-RAY STUDIES RELATED TO COATING THICKNESS MEASUREMENTS

1984 ◽  
Vol 45 (C2) ◽  
pp. C2-33-C2-36 ◽  
Author(s):  
D. A. Sewell ◽  
I. D. Hall ◽  
G. Love ◽  
J. P. Partridge ◽  
V. D. Scott
Keyword(s):  
Coating Thickness ◽  
X Ray ◽  
Thickness Measurements

Validation of Multi-Frequency Eddy Current MWM Sensors and MWM-Arrays for Coating Production Quality and Refurbishment Assessment

2003 ◽  
Author(s):  
Vladimir Zilberstein ◽  
Ian Shay ◽  
Robert Lyons ◽  
Neil Goldfine ◽  
Thomas Malow ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Eddy Current ◽  
Coating Thickness ◽  
Bond Coat ◽  
Gas Turbines ◽  
Corrosion Damage ◽  
Operating Conditions ◽  
Ongoing Research ◽  
Metallic Bond ◽  
Thickness Measurements

Coatings for oxidation, corrosion, and thermal protection provide the required materials performance for gas turbine blades and vanes in state-of-the-art industrial gas turbines. These turbines must withstand severe operating conditions for well over ten thousand hours. Variations in the coating thickness, and increased porosity, can influence the lifetime of such coatings significantly. For components that have been removed from service, effective assessment of the aged coating and substrate condition is critical for refurbish/replace/continue-to-run decisions. A suitable device for coating thickness measurement and detection of unacceptable porosity is needed for ensuring the quality of such coatings. In this paper, we present new results on coating thickness measurements for metallic MCrAlY overlay coatings on gas turbine parts. These measurements were performed with a Meandering Winding Magnetometer (MWM®) eddy-current sensor using grid methods. This technique allows proper coating measurements even after a diffusion heat treatment for a better coating adhesive strength. The MWM technology enables measurement of the coating thickness, the absolute electrical conductivity (which may in turn be related to porosity or other properties of interest), and lift-off, which is related to surface roughness. Single-channel MWM sensors and multi-channel imaging MWM-Arrays permit capture of features of interest for a population of components. New capabilities for inspecting gas turbine components are, thus, provided. Inspection applications include metallic and non-metallic coating thickness measurements, porosity measurements, and detection of cracks on complex surfaces. Results of coating assessment for a production line of gas turbine vanes by means of a multifrequency MWM technique are presented for various combinations of coatings and base metals. A description of improved multiple frequency quantitative inversion methods is provided for simultaneous and independent measurement of multiple unknowns such as metallic bond coat thickness, metallic bond coat porosity, and top coat thickness. Ongoing research focuses on characterization of aged components using MWM sensors and imaging MWM-Arrays as well as on development of enhanced algorithms for four and five unknown coating / substrate properties. In a recent study of hot corrosion, uncoated nickel alloy specimens were characterized using an MWM sensor with grid methods. Preliminary results indicated that, within the limitations of the three-unknown single-layer model used, the method could readily identify specimens with no apparent corrosion damage, specimens with moderate corrosion damage, and specimens with severe corrosion damage.

Unity of coating-thickness measurements

1984 ◽  
Vol 27 (12) ◽  
pp. 1079-1081
Author(s):  
L. S. Babadzhanov
Keyword(s):  
Coating Thickness ◽  
Thickness Measurements

On-Line X-Ray Fluorescence Spectrometer for Coating Thickness Measurements

1988 ◽  
Vol 32 ◽  
pp. 21-30 ◽  
Author(s):  
N. Matsuura ◽  
T. Arai
Keyword(s):  
Coating Thickness ◽  
High Efficiency ◽  
Iron Alloy ◽  
Nuclear Radiation ◽  
Pure Zinc ◽  
Steel Sheets ◽  
On Line ◽  
Zinc Coated Steel ◽  
Fluorescence Spectrometer ◽  
Thickness Measurements

The principles and techniques for performing coating thickness measurements in the laboratory and on-line using nuclear radiation have been established for tin or zinc coated steels. Recently, additional engineering efforts have been made toward the development of new coating substances consisting of complex layered materials. For example, zinc-iron alloy metal has higher corrosion resistance than pure zinc-coated steel sheets and evaluations have been made of beneficial characteristics in automobile production processes, such as easy welding, good paintability, high efficiency for press plastics forming, etc.

Micro Arc Oxidation of AZ91 Magnesium Alloy – Effect of Organic Compounds in the Electrolyte

2014 ◽  
Vol 353 ◽  
pp. 217-222 ◽  
Author(s):  
Namik Kemal Gozuacik ◽  
Mert Altay ◽  
Murat Baydogan
Keyword(s):  
Corrosion Resistance ◽  
Coating Thickness ◽  
Electrochemical Corrosion ◽  
Organic Chemicals ◽  
X Ray Diffraction ◽  
Az91 Magnesium Alloy ◽  
Micro Arc Oxidation ◽  
Az91 Magnesium ◽  
Alloy Effect ◽  
Thickness Measurements

AZ91 Mg alloy was micro arc oxidized under constant electrical parameters in silicate based and phosphate based electrolytes with and without addition of organic chemicals, namely Hexamethylenetetramine (HMTA), TRIS (hydroxymethyl) aminomethane (THAM) and Glycerol in two different concentrations. Following oxidation, samples were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), coating thickness measurements, hardness measurements and electrochemical corrosion tests. Results showed that coating layers mainly consisted of MgO, Mg2SiO4 and MgF2 for silicate based electrolytes, and MgO for phosphate based electrolytes. Incorporation of organic chemicals into electrolyte composition did not change the type of the phases in the coating. However, when they are added in silicate based electrolytes, pore density and coating thickness are reduced and pore size is increased. On the other hand, there is no significant change in surface morphology when organic chemicals are added in phosphate based electrolyte. In the view point of corrosion resistance, organic chemicals did not enhance corrosion resistance of the samples oxidized in silicate based electrolytes, but exhibited some increment in corrosion resistance of the samples oxidized in phosphate based electrolytes.

ETCH Rate and Thickness Measurements of Layered GaAs, AlAs and AlGaAs Structures Using a Laser Reflectance Technique

1994 ◽  
Vol 340 ◽  
Author(s):  
Louise H. Grober ◽  
M. Hong ◽  
R.D. Grober ◽  
J.P. Mannaerts ◽  
R.S. Freund
Keyword(s):  
Computer Simulation ◽  
Theoretical Model ◽  
Etch Rate ◽  
Etch Depth ◽  
Laser Reflectance ◽  
Layer Structures ◽  
Etch Rates ◽  
Thickness Measurements ◽  
Laser Reflectometry

ABSTRACTLaser reflectometry has been shown to be a useful tool for etch depth measurements during etching of multiple layer structures. We have extended the use of laser reflectometry to accurately determine the etch rates of GaAs, Al0.4Ga0.6As and AlAs as a function of temperature and to verify layer thickness in-situ. By use of computer simulation we compare a theoretical model to actual data to determine layer thicknesses and accurate etch rates. We compare our data to previously published work for GaAs etching.

Rainbow Field Test of Coatings for Hot Corrosion Protection of Gas Turbine Hot Section Components: II — Vane Coatings

1989 ◽  
Author(s):  
Mark Van Roode
Keyword(s):  
Gas Turbine ◽  
Field Test ◽  
Coating Thickness ◽  
Hot Corrosion ◽  
Liquid Fuel ◽  
Turbine Blades ◽  
Lower Grade ◽  
Metallographic Examination ◽  
Gas Turbine Blades ◽  
Thickness Measurements

A rainbow field test sponsored by the Electric Power Research Institute (EPRI) under contract RP 2465-1 was performed to evaluate the comparative hot corrosion resistance of commercially available coatings for gas turbine blades and vanes. A 10,307-hr field test was carried out on a Solar Centaur T-4000 gas turbine operating on a lower grade liquid fuel at the Owens-Illinois, Inc. glass manufacturing facility in Valera, Venezuela. This paper reviews the results of an evaluation of the performance of a simple aluminide, a Pt, Rh-aluminide and two MCrAlY (M = Co, NiCo) overlays applied to the first stage FSX-414 vanes. As found for blade coatings, on the basis of visual and metallographic examination, and remnant coating thickness measurements, it was established that the MCrAlY coatings were generally more effective than the simple aluminide and the Pt, Rh-aluminide in providing protection to first stage vanes. A remnant coating thickness index (RCTT) was used to express coating survival and protectiveness quantitatively. The results of the study have been compared with literature.

Coating-thickness measurements on parts with complex shapes

2013 ◽  
Vol 49 (7) ◽  
pp. 374-381
Author(s):  
A. A. Lukhvich ◽  
A. L. Luk’yanov ◽  
Ya. I. Shukevich ◽  
A. K. Shukevich ◽  
M. N. Polyakova ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Complex Shapes ◽  
Thickness Measurements
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