Implementing TI Billet Phased Array on the Shop Floor By Mark Pompe, West Penn Testing Group Jeff Umbach, Pratt & Whitney Experience at West Penn Testing

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 C- scan 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

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 Attenuation correction

49.2% is used for the attenuation comparison to the billet More Accurate Attenuation Comparison

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 peaked values recorded by the operator

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 –1/16 th 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 1/3 rd 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