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Hard Chrome Plating Bond Strength and Testing Methods For It
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Dear sir:
We are working on coating the cast iron engine cylinder with the hard chrome and now we would like to know if there is a way that we can measure the adhesion of the coating. Thank you for your attention, and your prompt response will be highly appreciated.
Sincerely yours,
Harsh KumarMINISTRY OF RAILWAYS - PUNJAB, INDIA
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Others may have a better idea, but I don't know how to test it directly. You can however plate a sample of the same material at the same time, but in an easier to work with geometry, and do an Ollard test. If you can find nothing about Ollard on the net, I can expound.
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 Ted Mooney, P.E. finishing.com Brick, New Jersey |
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We have seen references to The Ollard test and the Modified Ollard test and have never been successful in obtaining any information on the subject.
We supply HVOF applied coatings on chilled cast iron and have used ASTM C-633-79 to measure bond strength.
Can you please forward or refer us to any information on the Ollard test?
Could you also perhaps speak to the difference between the Ollard and the modified Ollard.
Does either apply or transfer to HVOF coatings or are they specific to chrome or certain materials and is the test specific to a certain substrates
Thank you,
David Antoniazzi- Torrington, Connecticut, USA
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Hi,
I'm a PhD student in mechanical science, and I'm also looking for some information on the Ollard test. I would be really grateful if you were able to send me some details on it.
Many thanks,
David MOULIN- Metz, France
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A reason why you are finding it hard to track down this stuff is that the test is very, very old. The Ollard test is from 1925 and the modified Ollard test (by Knapp) from 1949. You need access to a computerized literature search engine to find references about it, not a web search engine, and then you need access to the documents that the abstracts reference. Hopefully extracting one quick sketch each from ASM's "Course 22 - Electroplating" and the April 1977 issue of Metal Finishing is 'fair use' which the copyright holders will not object to. They show, respectively, the Ollard test and the modified Ollard test. The original test was applicable only to plating onto a round bar which is then machined down to 1" diameter, whereas the modified test can be used on rectangular test panels and involves less machining and setup.
In either case the jig is put into a tensile tester (maybe actually a compressive tester), and then a calculation is made based on the cross sectional area. I haven't actually seen these tests run, but the advantage of these tests over competing adhesion tests is that they measure the actual tensile strength of the bond. Good luck.
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 Ted Mooney, P.E. finishing.com Brick, New Jersey |
December 20, 2011
Q. I want to know bond strength value of hard chrome plating.
Dhananjay Patil- Kolhapur, Maharashtra, India
^- Privately contact this inquirer -^
December 20, 2011
Hi, Dhananjay.
My understanding is that the Ollard test has demonstrated perfect adhesion between steel and hard chrome plating, i.e., that the chrome will rip or the steel will rip before there is separation at the interface.
Regards,
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Ted Mooney, P.E. finishing.com Brick, New Jersey |
January 10, 2012
Dear Sir,
We have been trying to check the bonding strength of hard chroming. We made a bonding tester almost similar with Ollard test. The dimension of sample pieces before plating is 25.00 mm and the dia. after plating is 25.4 mm x 5 mm wide (the thickness of hard chrome 0,2 mm or 0.4 mm on diameter).
The gauge shown 4496 psi.
How to calculate the actual bonding strength?
How to calculate the area ?
Thanks in advance
Best Regards,
- Jakarta, Indonesia