Implementing TI Billet Phased Array on the Shop Floor

1
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

2
Overview

• History of WPTG involvement with Ti Billet
  Inspection
• Comparison to Existing Multizone Inspection
• Implementation Of Phased Array at WP
• Lessons Learned
• Q A

3
MultiZone Ti Billet at WPSioux City Accident
4
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

5
MultiZone Ti Billet at WP

• 3 Separate Systems
• Motion
• Acquisition
• Analysis

6
MultiZone Ti Billet at West Penn

• Billet followers held 4 to 7 MultiZone
  transducers

7
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

8
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

9
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
10
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 C-scan images
• 12 to 24 overscan

11
Alignment For Multizone Probes is on Billet Back
Surface Reflectionor 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

12
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

13
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.
14
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

15
Phased Array Calibration

• A DAC (TCG) is used in each zone with typical FBH
  standards
• The setup for 6 diameter inspection is shown

16
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
17
More Accurate Attenuation Comparison
49.2 is used for the attenuation comparison to
the billet
18
PA Data Analysis

• Software automatically evaluates the C-scans for
  Amplitude and Signal to Noise Ratio Defects
• Similar to MZ

19

• 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

20

• Excel file contains results from the automated
  analysis

peaked values recorded by the operator
21
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 lt 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

22
To Accomplish Implementation

• FAA approval (Beginning 4/2011)
• PW specification
• RR, Honeywell Specifications
• AMS Specification for Generic Use
• Equivalency to AMS-2631

23
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.

24
Q A