Engine Titanium Consortium - Center for Nondestructive Evaluation ...

system will be at GE, and evaluation of any other systems would be at a location to be agreed upon
by the technical team. Arrangements will be made to accommodate full team participation for all of
these evaluations. The laboratory scan results will be reviewed to identify a preferred configuration
for factory demonstration and potential implementation. The review will consider inspection
performance, equipment cost and complexity, operating speed, and other implementation factors.
A hybrid system using fixed focus for the outer zones and phased array for the center will be
considered as part of this evaluation.
If the final approach agreed to by the technical team for factory demonstration includes phased
arrays, additional work will be done to refine the sensor design for the selected array approach.
Manufacturer’s engineering specifications for the array system design (element geometry,
lens/mirror geometry, etc.) will be input into an array system computational simulation. Theoretical
system performance will be compared to laboratory measurements of array system response.
Discrepancies between model and experiment will be traced to underlying causes and resolved.
Models will then be used to optimize the design and set up for specific test standards targeted for
study including larger diameter billets.
Factory Evaluation: The multizone configuration will be used to perform factory evaluation of five
heats of 10” diameter titanium at a production inspection facility. Cost and detection sensitivity
assessments necessary for life management and implementation decisions will be gathered.
Components of cost assessment will include such items as system cost, longevity of equipment,
recurring equipment costs, daily operational/inspection costs, and costs associated with false calls.
Evaluation will include cut-ups of any finds. Details of metallography will depend on how many
indications are found, but it is anticipated that all finds will be evaluated to determine cause, and
one will be step-polished to obtain detailed sizing information.
Factory Demonstration: An industry-wide demonstration of the multizone system will be scheduled.
OEMs and titanium billet producers will be invited.
Assessment of Large Diameter Billet (>10” dia): Assessment of the sensitivity at larger diameters
will use 13” and 14” diameter standards. Existing 13” standards will be used, and a 14” chord block
standard with near-centerline targets will be designed and built. Initial assessment will be made to
baseline conventional inspection sensitivity either using transducers borrowed from suppliers, or by
requesting suppliers to perform the evaluation in-house. Evaluation of zoned fixed-focus capability
will use existing multizone transducers. Evaluation will follow a plan to be agreed by consortium
members. If the targeted 4x sensitivity improvement over conventional inspection has been
achieved for 13” and 14” diameters, the results will be documented and no further work pursued. If
improvement is still needed, a plan will be formulated following the best approaches (phased array
or improved fixed focus) identified for 10” diameter billet. The plan will be presented to the FAA as
continued work is expected to require funding redirection.
Attenuation Compensation Procedures: The current procedures used to measure and compensate
for material attenuation will be evaluated and improved. The current procedure for the multizone
inspection uses a pre-inspection of four short sections (1” long) of the billet to obtain an average
backwall echo amplitude. This is compared with an average backwall amplitude measured on the
calibration standard and the difference is used to calculate an attenuation compensation factor in
decibels per inch. A transducer focused at the billet center is used to make the measurements.
Quarterly Report – January 1, 2002 –March 31, 2002
print date/time: 6/6/2002 - 8:39 AM – Page 22