Engine Titanium Consortium - Center for Nondestructive Evaluation ...

Project 1:
Task 1.2:
Subtask 1.2.1:
Production Inspection
Titanium Billet Inspection
Inspection Development for
Titanium Billet
Team Members:
HW: Andy Kinney, Waled Hassan
ISU: Bruce Thompson, Ron Roberts, Frank
Margetan
GE: Dave Copley, Wei Li, Mike Keller, Jon
Bartos, Richard Klaassen, John Halase
PW: Kevin Smith, Jeff Umbach, Bob
Goodwin, Andrei Degtyar, Harpreet Wasan
Students: none
Program initiation date: June 15, 1999
Objectives:
• To provide a procedure to account for attenuation effects such that the variation between
calibration and inspection sensitivity is minimized.
• To demonstrate the ultrasonic equipment and techniques required to inspect titanium alloy
billets to #1FBH sensitivity for 10” diameter and below.
• To provide an initial assessment of sensitivity at diameters greater that 10”.
Approach:
Transducer Design Models: The design models will be reevaluated in detail to determine reasons
for discrepancies between predicted and measured transducer behavior observed during Phase I
work. This reevaluation will focus initially on assessing how well the input parameters used for the
models represent the physical behavior of the transducers. It is planned to begin with
characterization of piezo-electric elements prior to the addition of backing materials, and then
attempt to compare model predictions with experiment at subsequent stages of the manufacturing
process. This will involve working closely with a transducer manufacturer with one potential source
identified. Based on this exercise, modifications will be made to model input parameters or to the
model code to improve the prediction accuracy. Attention will also be paid to selection of
transducer materials with consistent and measurable properties, for example the machining of
lenses from solid material rather than using cast-in-place epoxy. Results will be shared with
transducer manufacturers to allow improvements in future products both for ETC and the broader
ultrasonic transducer user community.
Inspection of 10” Diameter Billet: Fixed focus inspection will be the primary technique in this task.
If this approach proves inadequate to meet program objectives, viable phased array technologies
will be reviewed to select a candidate technique with the most potential for meeting the program
objectives in consultation with the FAA.
Improved fixed focus transducers for 10” diameter billet will be designed. Results from Phase I
measurements (at 2.25” and 4.05” depths) will be used to identify the best combination of focal spot
Quarterly Report – January 1, 2002 –March 31, 2002
print date/time: 6/6/2002 - 8:39 AM – Page 20