What’s up guys?!?!?! It’s Michael with Michael Talks Metal back for more testing talks today. This time it’s Eddy, you know Eddy? No, not Eddie Murphy or Eddie Money or even Eddie Van Halen. It’s Eddy Current….and no that’s not a person, it’s a type of test known as Eddy Current Testing. Before we jump in I just wanted to say THANK YOU. We recently hit 2000 subs and I can’t be more proud of this channel. Thanks to each and every one of you who has presse3d that little subscribe button. I am gratful. So, our topic today is another of the inspection methods that can be used to check a metal part for defects without damaging the component being examined.
Eddy Current Testing ….EC for short; is a different test we’ve yet to discuss. It’s also a non destructive testing method that can be used to detect surface and subsurface defects in metals. This technique uses the principle of electromagnetic induction. An alternating electrical current in a coil will induce current flows in a conductive material within it. Both magnetic and nonmagnetic metals can use this technique as it relies on the electrical conductivity of the metal within the field.
Eddy current testing is often used to inspect bar and tubular mill products for defects in highly automated equipment. Material is fed through an inspection coil or coils. Defects or variations in the material being inspected alter the current flows in both the material and the sensing coil. Typically, a standard sample with a known defect is used to calibrate the instrument. Comparison of the electrical deviation of the sample defect to the same material without a defect establishes the criteria for acceptance and rejection of the material. In many inspection systems, a paint spray would be triggered to visually identify any defective sections of material. In others, defective material is automatically segregated from conforming material.
Eddy current testing can also resolve differences in other metallurgical characteristics that affect the conductivity of eddy currents. In other applications, it can be used to separate or sort dissimilar metals based on composition, microstructure, hardness or other properties.
Using a known “good” sample, significant differences in any of these characteristics would be identified for rejection or further evaluation. All Non Destructive Evaluation (NDE) is intended to confirm the quality of a part and requires careful planning. Many parts require inspections at multiple steps in fabrication. If you are a regular viewer of our video series, then you know that things can get very complicated in a hurry. This is where I remind you for the 110th time to CHECK THE SPECS!!!!!!!!
Thanks for watching, little heads up, there will NOT be a video next week so Happy Thanksgiving everyone here in the US and have a safe holiday. This is Michael with Michael Talks Metal. Michlin is a distributor and supplier of all things steel and metal! Check our website www.michlinmetals.com for more info. Missed last weeks video? Click here. Still here and haven’t subscribed? Click here. Thanks again for watching, this is Michael with Michael Talks Metal. I will see you 2 weeks Thursday same time, same place. I’m OUT!