Eddy Current Component Testing Experts
248-478-9490
Crack detection on highly-stressed rollers- a new ibg application for aerospace

A- A closeup of the probe disk on this two-channel system shows that probes can be easily adjusted to the different diameters of the parts.

B - Typical roller bearing part

Highly-stressed bearings for aeronautical jet engines must have flawless rollers. ibg has developed a system for 100% testing of these rollers. Flaws as small as 50 microns deep by 80 microns long are reliably detected! The new system has been certified for in-line testing by a major manufacturer of commercial and military jet turbines.

The system incorporates two-channel eddydector® instrumentation and an eddyscan® H2/30 rotating scanner for non-contacting testing. Crack inspection can be on rollers with diameters of 5.0-26.0mm and lengths of 5.0-32.0mm. Running at a maximum of 75mm/ sec, the system cycles at a maxi­mum of 204 parts/min.

The eddydector® crack detection instrument uses two test channels with two probes on a probe disk which can be adjusted to the different diameters of the rollers parts. Friction wheels guide the test parts at a constant speed, as they pass end-to-end through the eddyscan® unit, from which individual OK and non-OK rollers are each forwarded to a separate soft conveyor belt. Special provisions are made for extra gentle handling of the parts on both feeding and discharge of tested parts. Change parts and maintenance parts are kept in compartmentalized drawers below the test instrument.

This application was interesting to ibg because it extended our bearing testing experience with the specialized aviation/aerospace market.

Instrument on X-Y slide detects cracks and pores on ID bore surfaces

A new configuration of eddyscan® H designed for in-line high-speed crack and pore detection is mounted on an X-Y slide for testing I.D. bore surfaces.The system involves

high-precision automatic alignment of the bore axis for scanning. A ball bearing probe guidance gently centers the probe precisely in the cylinder bore hole. As soon as the rotating probe is introduced into the cylindrical bore hole, it can test an entire cylinder liner I.D. bore surface in seconds. A version of this versatile semi-automatic test system can test cylinder liners in engine blocks with three, four or six cylinders (another version can test six, eight and 12 cylinders). It is mobile, and can be moved quickly from the lab to the production floor, and can be integrated into the engine block processing line.

The rotating probe (above cylinder) is on an X-Y slide for positioning before it is automatically introduced into each cylinder bore hole for scanning the entire surface.

Crack detection system for cylinder liners tests entire inner and outer diameters

An ibg system for testing cylinder liners for cracks on the whole I.D. and O.D. of the part has been developed using a 3-channel eddydector® instrument. It scans a 90mm O.D. and 86mm I.D. (of 132mm length) in nine seconds, which allows pro­duction at 400 parts/hour.

Once scanned, OK parts are forwarded to the next processing step on the upper chute, while non-OK parts occupy the lower chute.

The entire inner and outer surface of a liner such as shown . (right) is scanned by three crack detection probes.

The liners are clamped and put into rota­tion (at 900 rpm) and two probes do the scanning for surface flaws on the O.D., while a third scans the I.D. The liners are gently separated as they enter the system and are passed singly to the test and discharge stations. OK parts are forward­ed to the next processing step on one level, while non-OK parts are diverted to a lower chute.
Like many automatic crack test sys­tems, this one replaces magnetic particle visual inspections

Detection of very small pores and cracks on camshaft lobes solved by new ibg developments

Reliable detection of very small pores and cracks on camshaft lobes is difficult, due to the complex shapes of these parts. Any solution useful as an in-line test system must be capable of testing all the lobes and journals automatically at production rates, so that there can be 100% testing in-line to guarantee zero defects from pores and cracks.

Responding to several automotive cus­tomers, ibg NDT Systems has recently developed solutions to this problem using eddy current methodology. Involving a combination of both special probe designs and instrument capabilities, the new ibg capability provides reliable detection of very small pores and cracks on camshaft lobes and journals. In the most difficult case in scanning the lobe surface areas, the negative effects caused by their highly variable shapes are canceled out quite effectively. And, like all ibg solutions, the method is easily incorporated into our production line test systems.

Pores as small as 0.4 mm are reliably detected, as are small cracks and small chips at edges of the lobes and journals.

Chart shows indications from 0.6 mm on lobe "A" vs. good surface area, "B." Signal to noise ratio is better than 10:1.

Example case showing probes guided precisely by double-bearing ceramic shoes and use of eight test channels.

Software program for grade verification on bars, tubing and shapes

A software program by ibg facilitates grade verification on bars, tubing and other shapes with eddy current. The system is faster than the conventional spark test or chemical analysis, and can be used for 100% testing to find and eliminate wrong alloy bars mixed in with good ones.

The program is based on ibg Preventive Multi-Frequency Testing method, which involves calibration with a known OK material. Using the program, readings are carried out continuously along the material length at up to eight different test frequencies. Each unit is tested several times, using a broad band of up to eight frequencies. Discrete variations in eddy current flow patterns (due to discontinuities from straightening, forming, sizing, etc.) may be ignored with a selectable percentage, defining how frequently the material must meet criteria along its length in order to pass. This selectivity greatly increases reliability and reduces false rejects

TOL FRQ FKT  
A 25.0 Hz 2.0 -AAAAAAAAAAAAAAAAAAAAAAAA
B 63.0 Hz 2.0 -BBBBBBBBBBBBBBBBBBBBBBBBBB
C 160 Hz 2.0 CCCCCCCCCCCCCCCCCCCCCCCCC
D 400 Hz 2.0 DDDDDDDDDDDDDDDDDDDDDDDDD
E 1.00 kHz 2.0 EEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
F 2.50 kHz 2.0 FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
G 8 00 kHz 2 0 GGGGGGGGGGGGGGGGGGGGGGGGG
H 25.0 kHz 2.0 HHHHHHHHHHHHHHHHHHHHHHHHHH
Decision "O.K." Decision "NOT O.K."
TOt FM FKT  
A 25.0 Hz 2.0 -AAAAAAAAAAAAAAAAAAAAAAAA
B 63.0 Hz 2.0 -BBBBBBBBBBBBBBBBBBBBBBBBBB
C 160 H2 2.0 CCCCCCCCCCCCCCCCCCCCCCCCC
D 400 HZ 2.0 DDDDDDDDDDDDDDDDDDDDDDDDD
E 1.00 kHz 2.0 EEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
F 2.50 kHz 2.0 FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
G 8.00 kHz 2.0 GGGGGGGGGGGGGGGGGGGGGGGGG
H 25.0 kHz 2.0 HHHHHHHHHHHHHHHHHHHHHHHHHH
by Bill Buschur
General Manager
Spring Seminars/Workshops successful, will be continued in 2003; Quality Show in Novi

ibg held well-attended, informativeSeminars/ Workshops in early Spring this year, concen-trating on locations in theGreat Lakes states and Ontario, Canada.

Based on the favorable reactions to these presentations, more are planned for next year. These technical presentations will be held in the southeast section of the country, covering topics of material properties testing and crack testing. Actual examples will be discussed, in addition to the presentation of some theory and guidelines for effective testing. If you work in this area, be on the alert for announcements of upcoming seminars during the 2003 Spring season.

In this issue of TEST Patterns, ibg you will find different applications of crack testing-on rollers, cylinder liners and cam shafts-as well as news of an eddyscan® H instrument mounted on a X-Y slide.

Meanwhile, back in Michigan, ibg will be exhibiting in the Quality

New video shows a variety of tests for cracks and pores

A new videotape available from ibg learly depicts three different applications of crack testing, as well as applications for heat treat and hardness patterns.

Cylinder liners of cast iron for a manufacturer of diesel engines are tested for cracks, porosity and heat treatment. The entire I.D. bore surface and end face are scanned for cracks and pores. And the induction hardened I.D. bore is tested at multiple locations for hardness, case depth and hardness pattern runout. Both the testing and feeding operations are shown. In addition, close-ups of defects detected by the system are included in the visuals.

Planetary pins with soft ends are tested for cracks on the cylindrical surface area and for hardness, case depth and hardness pattern run-out. The test rate is 7,200 parts per hour.

Cylinder liners also are covered in another sequence, showing testing for I.D. and O.D. cracks and porosity on the O.D. and I.D. surface areas. This section also shows close-ups of flaws detected by the testing.

Rocker pins for engine timing chains tested for heat treatment are the subject of another section of the video. This system displays a twin sorter, with a test rate of 7,200 parts per hour.

The video is available for presentation at your plant on request. Inquiries should be made to Bill Buschur at ibg (call 248-476-9490).

Expo Detroit in Novi on June 12-13. Novi is a suburb of Detroit, northwest of the city, adjacent to Interstate 96.

In addition, we welcome a new organization to the ibg team: Radiatronics, with Neil Breslow covering a number of mid-America states, including Missouri, Nebraska, Kansas, Colorado, Wyoming and New Mexico, as well as Arkansas in the South.

20793 Farmington Road
Farmington Hills, Ml 48336
248 478-9490
Fax: 248 478-9491
www. ibgndt. com
E-Mail: sales@ibgndt.com
ibg NDT Systems Corporation, 20793 Farmington Road, Farmington Hills, MI 48336
Phone: 248.478.9490, Fax: 248.478.9491
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