where expertise comes together - since 1996

Web's Largest Portal of Nondestructive Testing (NDT)
Open Access Database (Conference Proceedings, Articles, News), Exhibition, Forum, Network

All Forum Boards
Technical Discussions >
technical question for specific application
Career Discussions
Job Offers
Job Seeks
Classified Ads
About NDT.net
Articles & News

ULTRASOUND INSTITUTE
The Ultrasound Institute can develop new advanced ultrasonic measurement, imaging and NDT techniques for non-conventional applications.

410 views
08:08 Mar-18-2008
George Kim
technical question for specific application

I would like to know if there is an NDT technology that may be able to address a client’s need. The need is to determine the quality of a fused non-magnetic metal coating on a non-magnetic metal substrate. The deposit is sprayed onto the surface (200 to 500 micrometers thick) via thermal spray and fused to form a metallurgical bond by placing the coating/substrate system into a high temperature furnace. The coating is applied onto the ball component (1"OD to 16"OD) of ball valves and hence consists of a sphere with a bore that runs through it. The coating thickness may vary with each part. The client is seeking a means of determining whether there are any hidden flaws, i.e., cracks, pores, insufficient fusion, etc., within the coated parts.


Thank you.




 
07:23 Mar-19-2008

Michel

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
804
Re: technical question for specific application ----------- Start Original Message -----------
: I would like to know if there is an NDT technology that may be able to address a client’s need. The need is to determine the quality of a fused non-magnetic metal coating on a non-magnetic metal substrate. The deposit is sprayed onto the surface (200 to 500 micrometers thick) via thermal spray and fused to form a metallurgical bond by placing the coating/substrate system into a high temperature furnace. The coating is applied onto the ball component (1"OD to 16"OD) of ball valves and hence consists of a sphere with a bore that runs through it. The coating thickness may vary with each part. The client is seeking a means of determining whether there are any hidden flaws, i.e., cracks, pores, insufficient fusion, etc., within the coated parts.
:
: Thank you.

Hi Georges,

At first, I was going to suggest doing UT in immersion. But your coating is so thin, I don't think you could differentiate with the base metal. Since the coating and base metal are nonmagnetic, I would try Eddy Current. I remember doing thickness inspection on Learjet aircraft with this method. In my situation, I had 3 calibration piece of different thicknesses and I would set my instrument at the frequency, gain and phase angle which provided me with the best separation. In your situation, crack and pores maybe detectable, but I'm not so sure about the fusion. You may still have to test for this using UT?

Hope this may be of help to you, Cheerios!!!

Michel

End Original Message ------------




 


© NDT.net - The Web's Largest Portal of Nondestructive Testing (NDT) ISSN 1435-4934

Open Access Database, |Conference Proceedings| |Articles| |News| |Exhibition| |Forum| |Professional Network|