Magnaflux Quasar PCRT
Topics
• Functional Quality
• Magnaflux Quasar PCRT
• Detection Sensitivity
• System & Applications
Functional Quality
• Definition of Quality – Visual Quality – rejects parts with visual indications that exceed
specifications (subjective)
– Functional Quality – rejects parts with structural degradation that will cause premature field failure (objective)
• Functional Quality Requires NDT that:– Measures structural properties
– Provides results that are traceable to failure levels
– Provides quantitative and objective reject criteria
• Resonance Inspection is the only NDT method that meets these requirements
Resonance Theory Applied to NDT
• Resonant Frequencies are determined by the dimensions and material properties of the whole part
fr = resonant frequency k = stiffness (e.g., Young’s Modulus) m = mass (dimensions, density)
• Structural Defect = strength reduction caused by degraded material properties or dimensional variation
• …therefore, a defect that reduces stiffness will shift the resonant frequency
mkfr
Break Force vs. Resonant Frequency for PM Exhaust Flange
R2 = 0.9974
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450
31.500 32.000 32.500 33.000 33.500
Resonant Frequency - kHz
Bre
ak
Fo
rce
- lb
s.
Experimental Verification
Process Variations Can Mask Defects
Good Rod 1
Small Defect 1
Large Defect 1
Good Rod 2
Good Rod 3
Small Defect 2
Small Defect 3
Large Defect 2
Large Defect 3
Statistical Analysis of Masking
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0.80
1.00
21 21.1 21.1 21.2 21.2 21.3 21.3 21.4 21.4 21.5 21.5
Re sona nt Fre que ncy - kHz
Rel
ativ
e N
umbe
r
Good
Ba d
Ave ra ge Ra nge S igm aGood 21.24 1% 0.2%Ba d 21.11 6% 1.4%
Dis tr ibut ion o f R es onant F requenc ies fo r 200 M as te r C yl inder B od ies
A c c eptanc e W indow ~ R e jec ts 35% o f B ad P a rts
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0.20
0.40
0.60
0.80
1.00
21 21.1 21.1 21.2 21.2 21.3 21.3 21.4 21.4 21.5 21.5
Re sona nt Fre que ncy - kHz
Rel
ativ
e N
umbe
r
Good
Ba d
Ave ra ge Ra nge S igm aGood 21.24 1% 0.2%Ba d 21.11 6% 1.4%
Dis tr ibut ion o f R es onant F requenc ies fo r 200 M as te r C yl inder B od ies
A c c eptanc e W indow ~ R e jec ts 35% o f B ad P a rts
Relative Frequency Compensation
Good Parts Peak
Separation > 2.8 kHz
Bad Parts Peak Separation < 2.0 kHz
Silicon Nitride Valves
Temperature Compensation
• Critical for accurate measurements– Quasar total error 0.03%– Resonant frequency varies
with temperature• Ferrous – 0.015% per °C• Aluminum – 0.025% per °C
• Compensation measures part temperature (+/- 0.5°C) and computes equivalent frequency at baseline temperature
68.318 kHz
68.397 kHz
68.400 kHz
31°C
23°C
23°C
Compensation Accuracy = 99.995%
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1.00
-200
-167
-133
-100 -6
7-3
4 0 33 66 100
133
More
Predictor Error - Hz
Rel
ativ
e N
um
ber
Good
Bad
Acceptance Window Range = 0.3%
Process Compensation Unmasks Defects
Distribution of Predictor Error for 200 Aluminum Master Cylinders
Process Compensated Resonance Testing
• Resonance tests the whole part for all structural defects, material differences, and dimensional changes
• Process Compensation separates changes due to defects from those caused by normal process variations
• ASTM E2001-08 (RI) and ASTM E2534-10 (PCRT)
• Quasar PCRT takes the next step by applying statistical analysis and pattern recognition to accept or reject parts
• NDT acceptance is based on objective functional quality, not visual quality subject to operator error
MTS Pattern Recognition
Measured & Predicted Resonant Frequencies for 200 Aluminum Master Cylinder Bodies
MTS = Mahalanobis Taguchi System
21.00
21.05
21.10
21.15
21.20
21.25
21.30
21.35
21.40
21.15 21.20 21.25 21.30 21.35 21.40 21.45
Predicted Frequency - kHz
Measu
red
Fre
qu
en
cy -
kH
z
Good
BadMTS Acceptance Window
VIPR – Pattern Recognition Program
VIPR computes the MTS (good part characteristics) and Bias (bad part characteristics) to determine Quasar Score
Bias CutoffRejectAccept
MTS Cutoff
Reject
Accept
Bad Parts
Good Parts
Quasar Score Predicts Performance
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450
0 5 10 15 20 25 30 35 40
B r e a k F o r c e - P o u n d s
Quasar Score
Correlation = 99.8%
F = -6.8 Q + 424.5 Where: F is Break Force Q is Quasar Score
Detection Sensitivity
• Common question: – What size is the smallest defect that quasar can detect?
• Correct question: – How much performance degradation can quasar detect?
• Answer – detection threshold depends on several variables:– Definition of defect – statistically significant difference
• Defects must be structural, not cosmetic• Failure distribution must be statistically defined
– Measurement R&R (precision, temperature, tooling)– Available test time vs. Weight & complexity of part
0
5
10
15
20
25
30
Visual Prod X-ray Film X-ray ASNT FPI Quasar
# M
iscl
assi
fica
tio
ns
Good Part Errors Bad Part Errors
Fatigue Test of 64 Aluminum Knuckles
88% Effective
55% Effective
56% Effective
59% Effective
100% Effective
Consortium Test of NDT Methods
Quasar 4200 System
Work Station Test Station
Nest
Test Heads
Isolation Base
Flat Panel Display
Keyboard & Mouse
Computer & Transciever
Quasar 4000 System Block Diagram
Automation Interface PLC
• Senses Part• Raise / Lower• Test Results Test Station
Part
Drive Transducer
Receive Transducers (2)
DeviceNet
Thermocouple
Accept/Reject
Proximity Switch
Transceiver
Control Computer
User Interface
Workstation
System UPM
PLC
TEST HEAD ID
Step Motor Lift
Test Head Example
Test Part (Dampening Fork)
Tooling
Thermocouple (Under part)
Transducers (Under part)
Resonant Vibration Modes
Test Part (Connecting Rod)
Click for animation
Bending Mode Transverse
Bending ModeTorsional Mode
Application Example #1
Rocker Arm
Cast Visual Inspect
Machine/ Heat Treat
MPI 1X-Ray Sample
MPI 2
Autogage“Gas Hole” Inspection
Visual Cracks
Final Visual
Second Level Inspection
Pack /
Ship ~100/yrReturns
7%Scrap
20% of PriceNDT Cost
8NDT Opns.
Before Quasar PCRI
QuasarAutogageFinal
Visual
Pack /
Ship
Rough Inspect
CastMachine/
Heat Treat
0Returns
1%Scrap
4% of PriceNDT Cost
3NDT Opns.
After Quasar PCRI
Application Example #2
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-02
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-02
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-03
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Lea
kers
per
Mo
nth
Pre Quasar
Transition
Full Quasar Testing
2 year Production Log
Cast Aluminum Master Cylinders
2 suppliers – 12 million parts
Leakers occur when aluminum oxides provide a channel from bore to surface
Quasar Production Systems
Examples of Quasar PCRI Applications
ABS Pump Bodies Engine Mounts ABS Rings Flywheels
Bearing Caps Gears Brake Anchors Knuckles
Bearing Hubs & Races
King Pins Brake Calipers Links
Master Cylinders Oxygen Sensors Cam Caps Pump Housings & Rotors
Cam Shafts Rocker Arms Clutch & Pressure Plates
Steering Racks
Connecting Rods Sprockets Control Arms Synchronizers
Dampener Forks Timing Rings & Gears
Differential Carriers
Transmissions Shafts
Cylinder Heads Wheels Engine Blocks Yokes
Examples of Structural Defects
Al Cast Fe Cast PM Forge
Oxides Oxides Oxides Bar Ends
Cold Shuts Cold Laps Chipped Teeth Double Strikes
ShrinkPorosity
ShrinkPorosity Porosity Laps (folds)
Blow Holes Nodularity Sintering Water quench
Elongation Heat Treat Coining Wrong material
Carbides De-carb
Common Defects – All Processes
Cracks, Inclusions, Chemistry, Missing Features, Non-fill, Dimensions
Process-Specific Defects
Other Processes – Welding, Ceramics, Composites
Quasar PCRI – Production NDT Benefits
• Lower Risk – Lower probability of shipping defective parts
– Proper use reduces the risk of “quality spills” into the field
– Boost company marketing image
• Lower Cost– Reduced NDT Cost
– Reduced false-rejects and scrap of good parts
– Reduced returns and warranty costs associated with “quality spills”
www.magnaflux.com
Magnaflux Quasar Systems5550 Midway Park Place NEAlbuquerque, NM 87109 Phone: (877) 847-3067Fax: (505) 212-5422
Magnaflux Global HQ3624 West Lake Avenue
Glenview, IL 60025Phone: (847) 657-5300
Fax: (847) 657-5388
The Next Step in NDT
Magnaflux Quasar Systems