1. Non Destructive Testing: Finding Defects in Metal Objects
Design Team 4:
Chad Church
Ron Fox
John Vogel
Geoff Brigham
Matt Hamm

2. Agenda The Need For Non-Destructive Testing Methods of NDT Summary
Eddy Currents
Acoustic
Ultrasonic Testing
Summary

3. Non-Destructive Testing
“Test object, material or system without impairing its future usefulness”
Industrial Application
Crack Detection
Wall Thinning
Porosity
Thickness of Material
Medical Application
Ultrasound
X-Ray

4. Benefits of NDT Ensure Product Integrity To Avoid Failures
Better Product Design
Lower Manufacturing Costs
Maintain Uniform Quality Level

5. Methods of NDT Visual Testing Penetrant Testing
Magnetic Particle Testing
Infrared/Thermal Testing
Eddy Current Testing
Acoustic Emission Testing
Ultrasonic Testing

6. Method: Eddy Currents Eddy current probe is a coil of wire
Induces a magnetic field
Induces a current in the part
Induces a current in the probe
Measure the Current
VICTORY!

7. Method: Eddy Currents Detect: Depth of penetration “Skin effect”
Conductivity
Magnetic Permeability
Distance
Presence of a flaw
Depth of penetration
“Skin effect”
Exponential drop-off

8. Method: Eddy Currents
Limitations
Aluminum parts
Iron parts

9. Method: Acoustic Testing
Inspiration: Hit it with a hammer, listen
Resonance frequency
Harmonic frequencies
Fourier transform

10. Method: Acoustic Testing
Mechanical impact on different locations
Microphone reception
Fourier Transform
Correlation of multiple impact resonations
doi: /jaer     

11. Method: Acoustic Testing

12. Method: Acoustic Testing

13. Method: Acoustic Testing
Variety of material and composition
Environmental deterioration
Damping
Access to many points

14. Method: Ultrasonic Testing
What is Ultrasound?
Sound Waves
100 KHz to 50 MHz for NDT
Short Wavelength
Reflections Off Small Defects
Requires Elastic Medium

15. Method: Ultrasonic Testing
Components of an Ultrasonic Flaw Detector
Power Supply
Timer
Pulser/Amplifier
Ultrasonic Transducer
Receiver
Computer Display

16. Method: Ultrasonic Testing
Ultrasonic Transducer
Electrical Energy Mechanical Energy
Piezoelectric Effect
Alternating Voltage Applied To Crystal
Crystal Expands and Contracts
Creates High Frequency Alternating Charge on Crystal

17. Method: Ultrasonic Testing
Couplants
High Frequency/Short Wavelength
Minimal Propagation in Air Medium
Types of Couplants
Oil
Glycerine
Water
Another Option
Direct Contact Transducer

18. Method: Ultrasonic Testing
Advantages of Ultrasonic Testing
Fast Response
Accuracy
High Sensitivity
Flexibility
Penetrating Power

19. Method: Ultrasonic Testing
Limitations of Ultrasound
Sensitivity
Resolution
Noise Discrimination

20. Summary Necessary to use a Non Destructive Testing Eddy Currents
Abilities
Problems
Acoustic
Ultrasound
Team Designed Method (

21. Questions?