Contents of Materials Performance - MAR 2012

Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.

Page 18 of 84

MATERIAL MATTERS Continued from page 15
also includes algorithms that can combine the individual photo analyses to generate condition assessments of the coating by zones, as well as automatically produce a re- port of inspection results in a standardized format that can be uploaded into the Navy's databases. Although the image-
This is an original photo from the image set taken of the USS
assessment in 2010. Photo courtesy of the Naval Research Laboratory.
during an image-based coating
The original image was analyzed by the TCDA, which reports the corrosion damage (shown in red in this output image) as 0.29%. Photo courtesy of the Naval Research Laboratory.
based inspection process can't provide quantitative measurements of coating tensile adhesion and dry ÅTU \PQKSVM[[ ,.< Q\ LWM[ qualitatively evaluate these coating properties, Wegand says. By identifying coated []ZNIKM[ _Q\P ÆISQVO JTQ[\MZ- ing, and delamination, the ).<+)< I[[M[[UMV\ XZW- vides a strong indication where coatings adhesion strength is low. Addition- ITTa \PM ).<+)< KWTWZ uniformity assessment, which determines areas where a number of over- coats have been applied to a surface, shows where the KWI\QVO¼[ ,.< UIa JM higher than the specified allowance.
Exactly how the new
The original image was analyzed by the AFTCAT coatings non-uniformity algorithm, which reports a coating non-uniformity value of 36%. The output image (above) enhances the hue variations in the coating. Photo courtesy of the Naval Research Laboratory.
16 MATERIALS PERFORMANCE March 2012
coatings assessment process could be implemented is still being determined by the 6I^IT ;MI ;a[\MU[ +WU- UIVL 6)>;-) _PQKP sponsored the research. One possible application is to use the results from an image-based coating assess- ment to establish a baseline for a ship's coatings perfor- mance and then monitor coatings performance over \QUM [Ia[ KW]TL \PMV JM XMZNWZUML personnel, and costs required to conduct a fully manned coating assessment vs. an image-based assessment, Wegand refers to the coatings assessment of the aircraft carrier, USS Nimitz, that the NRL re- search team conducted in 2009. A tradi- tional physical assessment of the topside coating, with the support of eight to 10 sailors from the ship, required a total combined effort equivalent to 65 man- days plus the use of multiple barges and [Q` XMZ[WVVMT TQN\[ PM [Ia[ 1\ \WWS IVW\PMZ NW]Z _MMS[ \W IVITabM \PM QV[XMK\QWV LI\I and generate a report. At the same time, the researchers also performed an image- based coating inspection of the USS Nimitz. Using two hand-held digital cam- eras, a two-person team collected over 3,000 photographs of the aircraft carrier's topside surfaces, which they analyzed _Q\P \PM ).<+)< 1V TM[[ \PIV NW]Z LIa[ the coatings condition of the aircraft car- rier was recorded and evaluated. Since then, the researchers have
simplified the process to reduce the number of photos required to conduct an image-based coating assessment and performed this type of assessment on ^IZQW][ 6I^a []ZNIKM [PQX[ Bibliography
;TMJWLVQKS 8 3 ;IV\IVOMTW 2 ?MOIVL M\ IT ¹) :IXQL IVL +W[\ -NNMK\Q^M 5M\PWL NWZ 8MZNWZUQVO 6)+- 1V\MZVI\QWVIT NACE International, Vol. 51, No. 3
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