Imagine a safety belt failing in an emergency. Then you will recognize how vital a small component such as a buckle can be (see photo above). The buckle could save your life— but to do so, it must be correctly heat treated and be of the correct alloy. It must have correct material properties. Thus, nondestructive eddy current testing becomes critical.

Unexpected mixed microstructures caused by only partially-wrong heat treatment, as well as soft parts from entirely-missed heat treatment, must be reliably detected. Utilization of ibg Preventive Multi- Frequency Testing (PMFT) technology provides reliable detection of such dangerous partially-heat-treated parts. The testing has been successfully applied to many safety-critical stamped parts, including safety belts, seat and door components and parking pawls; plus fuel injector and air bag components.

Testing on such critical parts as these is typically done on 100% of the parts, though it is also done on a sampling basis, with an option to easily 100%-test suspect lots.

The photo at left shows an automatic test system that includes a feed conveyor, test instrument, sorting station and a color marking apparatus. Depending on a customer's requirements for such stampings, cycle times of 1 sec/part can be achieved. With a Twinsorter, the timing can be as short at 0.5 sec/part; and with a Quattrosorter the cycle can be a short as 0.25 sec/part.

More eddyscan®H high-speed roller crack test systems

Roller applications range from small 1.5 mm diameter needles tested with eddyscan®H10 up to rather large 70 mm diameter rollers tested with eddyscan®H70, and they must be fast-up to 36,000 parts per hour-in order to exceed the production process. In the case illustrated in the photo directly above, eddyscan®H 63 tests rollers up to 63 mm in diameter.

The eddyscan®H 63 can be equipped with up to four probes (e.g. four channels) with up to 12,000 rpm rotation.

Thus, feed speeds up to 800 mm/sec. are possible. The rollers are pushed through the rotating head, end to end. Converting to a different part type is possible within a 15-minute sequence.

In the photo shown at the bottom of this column, a test system for needles, in which the needles are fed vertically to a rotating scanner, is illustrated. All the test systems shown here were designed according to customers' requirements.