Implementing TI Billet Phased
Array on the Shop Floor
Experience at West Penn Testing
By
Mark Pompe, West Penn Testing Group
Jeff Umbach, Pratt & Whitney
Overview
• History of WPTG involvement with Ti Billet
Inspection
• Comparison to Existing Multizone Inspection
• Implementation Of Phased Array at WP
• Lessons Learned
• Q&A
MultiZone Ti Billet at WP
Sioux City Accident
MultiZone Ti Billet at West Penn
• Operated GE MultiZone system 1995
through 2004
• First Production System installed after Initial
RMI test bed
• Over 22 million lbs of rotor grade Ti billet
were inspected
• Testing has transitioned to billet producers
MultiZone Ti Billet at WP
• 3 Separate
Systems
– Motion
– Acquisition
– Analysis
MultiZone Ti Billet at West Penn
• Billet
followers
held 4 to 7
MultiZone
transducers
WPTG Phased Array Involvement
• Operating Phased array systems since
2000 on wrought product and
Composites
• Volunteered to be a test bed for Ti
Billet Phased Array Project in 2008
Modifications for PA trial at WP
• Modified Follower to hold 5” diameter
Phased Array Transducer
• Re-configured MZ prototype gimbal,
commercial gimbals too fragile, test can
be violent with bent billets.
• Added auxiliary encoders for X axis and
rotational position – Passive System
Modifications for PA trial at WP
• Follower/transducer configuration shown for start of billet scan
• The lead rollers are on the billet and the back rollers, not visible in
the photographs, are not yet on the surface.
Phased
Array
transducer
Why Consider Phased Array?
Phased Array
• 5 min setup
– One Transducer 6” to
10”
• Evaluation 2 C-scan
images
• No over scan for rack
of transducers
Multi Zone
• 2 to 4 Hour Setup
– 3 sets of 4 to 6
transducers
• Evaluate 4 to 6 Cscan images
• 12” to 24” overscan
Alignment For Multizone Probes is
on Billet Back Surface Reflection
or FBHs
• Internal Ti Billet structure steers the beam
off axis, normal to back wall is not normal
to FBHs
• Can add hours to setup for 4 to 6
transducers
Alignment for Phased Array is
performed on the billet front surface
• 9 elements of the transducer used to align the
transducer on the surface of the sample
• Alignment completed in ~5 min
time
Alignment is performed on the billet
surface
Mis-alignment in
the circumferential
direction is noted
because on pair of
elements is closer
to the surface than
the other pair.
Multizone Calibration
• Each Transducer is calibrated on a FBH at
the start and end of the zone
• The two FBHs are equalized by Water Path
Adjustment to within 3 dB.
• Complicated by difficulty in normalizing
Phased Array Calibration
• A DAC (TCG) is used in each zone with typical FBH standards
• The setup for 6” diameter inspection is shown
Channel gain = 1 dB
Sum gain = 42 dB
Filter = 5 MHz band pass
Channel gain = 2 dB
Sum gain = 42 dB
Filter = 5 MHz band pass
Attenuation correction
• An acquisition file is made utilizing 7 sweeps
to help guarantee that the backwall is
sampled with the beam as normal as possible
Gate on the backwall
signal
7 sweep angles
with the beams
focused at the
backwall
More Accurate Attenuation Comparison
49.2% is used for
the attenuation
comparison to the
billet
PA Data Analysis
• Software automatically evaluates the C-scans
for Amplitude and Signal to Noise Ratio Defects
• Similar to MZ
• The automated software applies the criteria for both zones and
displays the rejectable and reportable signals
• The table is also written to an Excel file with scan information to be
used for a report
• Excel file contains results from the
automated analysis
PA Billet Inspection Report
Data File:
Time:
D:\PA data\Ti Billet Inspection\West Penn\6-in dia\B3W3A rerun 4-13-10 Report.xls
16:11:23 4/13/2010
Operator:
J Umbach
Billet ID:
B3W3A 4-13-10
Billet Length (inches):
34.8
Axis Inspection Range(inches):
34.9857
Billet start axis position for evaluation:
0.5
Billet end axis position for evaluation:
34.3
Calibration Amplitude (%FSH of #2 FBH calibration):
80
Calibration Gain(dB):
0.43
Transducer SN:
6511
Amplitude reject level (%FSH of #2 FBH calibration):
70
Signal to Noise Ratio reject value:
2.5
Reportable amplitude value(%FSH):
40
OR Reportable Amplitude/Averge Noise Rate:
3
Search Angle Width:
20 Angle Incr
Seacrh Axial Width:
2 Axial Incr
Indications:
4
#
Channel
1
2
3
4
2
2
2
2
NZ
channel
gain=2
20
20
22.8
25.8
15
1.75
Axial position
Angle Position
TOF
22.5857
161.6
22.6226
162.8
23.0655
161.6
26.2024
105.6
DZ
channel
gain=1
attn cor.
0.4256
20.08512
20.2128
15 23.14048 15.34048
7.9
26.332
8.432
4.3
5.02352
4
4.91504
7.7
8.80656
9.3
10.59808
10.8
12.2896
peaked values recorded
by the operator
Inspection Results: Reject
Gate
A
A
A
A
40281
at West Penn
5.55
5.54
5.38
9.78
Amp(%) SNR
Noise
84.31
9.73
11.11
63.53
6.72
10.81
39.61
3.84
10.98
32.55
2.51
11.26
Status
Reject
Reject
Reject
Reject
84.50%
32.50%
Lessons Learned
• P/A set up at WP on several occasions in 2010 on two
systems, 6” and 10” Billet
• Encoder vs position
• Follower Stability
– 1/16th to ±1/4 typical spec for Water Path
– Best Possible for PA < 1/16”, you can see it in the data.
• Operator Training – prior c-scan experience – 2 operators
were quick studies.
• Tomoview Software designed for engineers
• Procedures can be worked out for operators
• PW generating focal laws initially, need a source for this.
• Single Probe, Alignment and DAC dramatically reduces setup
• New Standards needed, can use simpler design
To Accomplish Implementation
•
•
•
•
•
FAA approval (Beginning 4/2011)
P&W specification
RR, Honeywell Specifications
AMS Specification for Generic Use
Equivalency to AMS-2631
Cost Comparison MZ vs PA
•
•
Instrumentation – MZ built and maintained by one source with 1990s
components. P/A should have multiple sources (Olympus, Peak, others
possible)
Transducers – Phased Array is 1/3rd of cost for 6” to 10”,
– One Phased Array Probe vs 3 sets of 4 to 6 MZ probes.
– Spares are needed for either.
– Both single source (Same source), more expense to develop another source.
•
•
•
•
•
Integration – Possible through inspectionware with peak instrument,
Separate motion control and data collection/Analysis with Olympus.
Followers – readily modify off the shelf units (Tac Tic for ours) vs complex
custom builds
Phased Array requires new calibration standards with additional FBHs
Evaluation PC integrated with data collection pc, simplifies maintaining PCs,
PCs are off the shelf running modern operating systems.
Phased Array purchase price is lower, maintenance is significantly lower.
Q&A