Quote:
Originally Posted by Tim Corcoran
HF Eddy current is only applicable to aluminum it is not used on iron, steel or other metals. Ultrasonic is usually used on composite materials to determine if there is delamination or voids. Radiography (x-ray) is very expensive, requires very expensive equipment and would cost a lot of money to have an engineer write a test plan to inspect an automotive crankshaft it, would cost more than the price of my new engine will. Dye penetrant will detect surface discontinuities and cracks not normally visible to the human eye. Mag particle (magnaflux) can detect surface and sub surface discontinuities, there are two basic types wet and dry. Most machine shops use the dry method using a dry magnetic dyed powder and applying a current through a set of prods to the test article. The dry mag inspection is only as accurate as the operator is trained and is not the most accurate method and can miss a lot or give inaccurate results. Wet mag particle is much more accurate but requires more specialized equipment and training and these inspections should only be performed by a level II certified technician. The type of dye penetrant that would be used in a machine shop is simple but is very accurate and does not require a lot or training or skill just follow the procedure that comes with the kit. I have been trained and certified a level II in magnetic particle, Radiography, dye penetrant and HF Eddy Current. I would leave it up to a level III to determine if dry mag or dye penetrant was a better test method to inspect for crack in a crankshaft.
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Quote:
Originally Posted by Tim Corcoran
We were talking about my engine failure, and you butted in saying how eddy current, X-ray and ultrasonic were more accurate and those are not even applicable to a Pontiac crank shaft which is a bunch of bull. You didn't even have any business contributing to this thread if all you wanted to do is criticize an NDT method that actually found cracks. Stay out of my post.
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No, what I said were eddy current, x-ray and ultrasonic inspection methods are more accurate than dye penetrant, which is FACTUAL. There ARE valid reasons WHY FAA. EASA, DOD, NASCAR, NHRA, IHRA, USAC, IMSA, SCCA, etc mandate magnetic particle inspection over dye penetrant when inspecting ferrous components. If you choose to use dye penetrant, that is your business. It’s something I would NOT encourage as a retired engine machinist.