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Explore the applications of Magnaflux Quasar PCRT for precise detection sensitivity and quality assurance. Learn how Resonance Inspection and Process Compensation unmask defects, enhancing NDT acceptance criteria. Discover the statistical analysis and pattern recognition employed by Quasar PCRT to ensure objective functional quality over visual quality.
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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
Experimental Verification Break Force vs. Resonant Frequency for PM Exhaust Flange
Process Variations Can Mask Defects Good Rod 1 Small Defect 1 Large Defect 1 Good Rod 2 Small Defect 2 Large Defect 2 Good Rod 3 Small Defect 3 Large Defect 3
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 23°C 68.400 kHz 31°C 68.318 kHz 23°C 68.397 kHz Compensation Accuracy = 99.995%
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 MTS = Mahalanobis Taguchi System MTS Acceptance Window Measured & Predicted Resonant Frequencies for 200 Aluminum Master Cylinder Bodies
Reject MTS Cutoff Accept Accept Reject Bias Cutoff VIPR – Pattern Recognition Program Bad Parts Good Parts VIPR computes the MTS (good part characteristics) and Bias (bad part characteristics) to determine 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
Consortium Test of NDT Methods 88% Effective 55% Effective 56% Effective 59% Effective 100% Effective Fatigue Test of 64 Aluminum Knuckles
Quasar 4200 System Test Station Work Station Flat Panel Display Nest Keyboard & Mouse Test Heads Computer & Transciever Isolation Base
Receive Transducers (2) Proximity Switch Drive Transducer User Interface Thermocouple Part Control Computer Transceiver Accept/Reject PLC DeviceNet System UPM Workstation Quasar 4000 System Block Diagram Step Motor Lift TEST HEAD ID Automation Interface • PLC • Senses Part • Raise / Lower • Test Results Test Station
Test Head Example Tooling Test Part (Dampening Fork) Thermocouple (Under part) Transducers(Under part)
Resonant Vibration Modes Test Part (Connecting Rod) Bending Mode Transverse Bending Mode Torsional Mode Click for animation
Before Quasar PCRI NDT Opns. 8 Visual Inspect X-Ray Sample Machine/ Heat Treat Cast MPI 2 MPI 1 NDT Cost 20% of Price Scrap 7% Pack / Ship “Gas Hole” Inspection Final Visual Second Level Inspection Visual Cracks Autogage Returns ~100/yr After Quasar PCRI NDT Opns. 3 Pack / Ship Machine/ Heat Treat Final Visual Rough Inspect NDT Cost 4% of Price Cast Autogage Quasar Scrap 1% Returns 0 Application Example #1 Rocker Arm
Application Example #2 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
Examples of Structural Defects 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”
Magnaflux Quasar Systems The Next Step in NDT www.magnaflux.com Magnaflux Quasar Systems 5550 Midway Park Place NE Albuquerque, NM 87109 Phone: (877) 847-3067 Fax: (505) 212-5422 Magnaflux Global HQ 3624 West Lake Avenue Glenview, IL 60025 Phone: (847) 657-5300 Fax: (847) 657-5388