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

200

250

300

350

400

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

0.00

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

0.00

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%

0.00

0.20

0.40

0.60

0.80

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

200

250

300

350

400

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

0.0

1.0

2.0

3.0

4.0

5.0

Mar

-02

May

-02

Jul-0

2

Sep-0

2

Nov-02

Jan-0

3

Mar

-03

May

-03

Jul-0

3

Sep-0

3

Nov-03

Jan-0

4

Mar

-04

May

-04

Jul-0

4

Sep-0

4

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