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Crack detection and a new inner diameter test coil procedure are highlights of this issue

Crack detection via eddy current is a valued method to test components for surface defects today. In a few words, it is fast, reliable, repetitive, non-destructive and it can be automated. As it is replacing the human eye more and more these days, it deserves being featured in this issue of our newsletter. With automatic crack testing, you can test ball studs, brake discs, hubs, bearings and many other parts that are critical to the safety and integrity of automobiles. ibg can apply some of the latest innovations and developments to find sub-surface defects or scan part geometries for flaws.

Also in this issue is news of a new development by ibg. This involves inner diameter coils which can reach into inner zones of components such as the bells of CV joints to test for correct structure. The story about this is below on the left.

Technical Seminars./Workshops took place in March and April of this year all over the world, and more than 200 participants were involved in Europe and the U.S. alone. Further such events are scheduled for later in the year in Europe and South America. If you missed this year's sessions in the southeast U.S., be sure to watch for listings for 2004.


Bill Buchur

Test part being fed to the test coil by a vibration bowl. Following the test, parts are sorted into OK and NOK lots. Cycle time is approximately one second.

Heat treatment specialist for small, vital parts utilizes eddyliner® P for testing

For over a half-century, Härterei Gerster in Switzerland has specialized in heat treatment for very small parts for clocks and watches, critical safety parts for the automotive industry and other components. For the automotive industry in particular, heat-treated parts are required to be 100% tested to verify correct heat treatment and part geometries to avoid wrong heat-treated and incorrect parts being installed.

ibg's eddyliner® P instrumentation is applied with multi-frequency technology to the automotive parts. Two test systems do semi-automatic testing, while automatic testing takes place for large batches with vibration bowls and other feeding devices. Changing to different part types takes only minutes, allowing small batch sizes to be tested efficiently.

ibg workshops draw hundreds of participants

Our workshops have evolved into an international forum for informing attendees generally on component testing as well as focusing on special applications. More than 200 persons attended workshops in March and April this year in Stuttgart, Wolfsburg and Besançon overseas, plus Atlanta and Nashville in the U.S. Later this year, further events are scheduled in Great Britain, Mexico, Brazil and France.

Crack detection system for gear switch forks requires innovative test approach

Until now, eddy current crack detection on parts was limited to symmetrical components. This was because either the test part or the probe would rotate around to detect flaws. However, crack testing on gear switch forks at the area of highest stress had to be different. (Note the area to be tested in the photo.)

ibg reacted to a customer who needed automated crack detection to replace labor-intensive, unreliable magnetic particle inspection.

The parts are fed via a gripper to where they are positioned in the test station. Then, the area of the fork to be tested is scanned with a contacting probe, which is protected from wear by a ceramic probe holder.

During testing, the probe transmits the test signals to an eddydector ® test instrument which is calibrated with a defined artificial crack. After the test, each part is paint-marked according to the test result and is discharged to an OK or NOK chute. The test cycle is eight seconds per part.

A master part is fed into the system at programmable intervals to guarantee a consistent and faultless test.

Automatic crack test system monitors 22-pound hollow trailer axle shafts

An automatic crack detection system was designed and manufactured for an American supplier of trailer axles. The parts are cold-extruded hollow shafts which , serve as bearing seats. The weight (22 lbs.) and geometry of the parts challenged ibg to some special design work.

The system works as follows: A gantry robot places the test parts in pairs on an indexing table, which takes them to the crack test station. There, the parts are rotated and a probe scans the entire outer surface of the shaft for both longitudinal and circumferential cracks. An eddydector® instrument is used for detection in 54-second cycle times.

In addition, the test system can be extended with a further station for structure testing, where parts are checked for correct hardness at different locations or for material mix.

Among the advantages of a system A such as this automatic NDT test is I that results do not depend on human eyes, and are always repeatable by the electronic test instrument.

Tube, bar and wire testing for alloy verification with eddyliner® P

The eddyliner® standard test instrument using Preventive Multi-Frequency Technology has been used for hundreds of applications in the automotive field worldwide. Now it can be applied to tube, bar and wire manufacturing to verify correct alloy.

As material is continuously passed through the test coil, measuring is triggered at defined intervals to find differences in the structure due to wrong alloy. After the material exits the test coil, a PLC decides if the test part is OK or NOK --i.e. if it is the correct material alloy specified. Five such systems were installed in Europe and Asia in 2002.

ID coils test inner surfaces of automotive components

A new capability of ibg involves coils for applications requiring the testing of the inner diameter of components.

The usual procedure for eddy current structure testing is to use encircling coils. Test parts are positioned in the coil and testing is carried out. Applications requiring testing on the inner diameter of a component have been difficult because this area cannot be reached by encircling coils from the outside, as this zone can not be sufficiently penetrated by a magnetic field. Typical examples of this situation are bearing races on the inside of the bell of a CV joint or tripod.

Now, ibg can test these ID areas to verify correct hardness and case depth with satisfactory sensitivity and reliability using inner diameter coils custom-made for customers' applications. The ID coils can be supplied .in diameters from 5 mm.

"Modular" training for operators and others now available from ibg

Demand for customized training has increased over the years, and ibg is responding to these needs. Whether it involves operator training in crack and structure testing or a general introduction and training for a large group of participants, explaining the basics of eddy current testing of com­ponents has become an obligation of ibg. The actual training session depends on each individual case, and can be held at the ibg office or at a customer's site.

If you are interested in training, please contact our U.S. headquarters office, or call 248-478-9490.

ibg's new Web site shows test instruments and sample systems

The Web site for ibg has been revised to show an array of eddy current instruments and systems for the non-destructive testing of components. Separate sections show hardness, structure and materials testing instruments, with a selection of systems; plus crack and flaw testing instruments, also with example systems. At least 15 different systems are shown in the site, including the components they test.

ibg reacted to a customer who needed automated crack detection to replace labor-intensive, unreliable magnetic particle inspection.

In addition, the new Web elements include detailed characteristics of the major products, involving the eddyliner® eddynomic®, eddysort®, eddydector®, and eddyscan® products, plus coils and probes. Also included is background on ibg, the company, and a listing of some of the companies for whom systems have been produced.

The new site should be up and running on the Internet about the time this issue of TEST Patterns is published. Look for it at: www.ibgndt.com.