tailieunhanh - NONDESTRUCTIVE TESTING

Nondestructive evaluation (NDE) encompasses those physical and chemical tests that are used to determine if a component or structure can perform its intended function without the test methods impairing the component's performance. | CHAPTER 25__ NONDESTRUCTIVE TESTING Robert L. Crane Theodore E. Matikas Air Force Wright Laboratory Materials Directorate Nondestructive Evaluation Branch WL MLLP Wright Patterson Air Force Base Dayton Ohio INTRODUCTION 729 LIQUID PENETRANTS 730 The Penetrant Process 730 Categories of Penetrants 730 Reference Standards 730 Limitations of Penetrant Inspections 730 ULTRASONIC METHODS 732 Soundwaves 733 Reflection and Transmission of Sound 733 Refraction of Sound 735 The Inspection Process 737 RADIOGRAPHY 738 The Generation and Absorption of X Radiation Neutron Radiography 739 740 Attenuation of X Radiation 741 Film-Based Radiography 742 The Penetrameter 743 Real-Time Radiography 744 Computed Tomography 744 EDDY CURRENT INSPECTION 746 The Skin Effect 746 The Impedance Plane Liftoff of the Inspection Coil from the Specimen 746 747 THERMAL METHODS 750 Infrared Cameras 750 Thermal Paints 751 Thermal Testing 751 MAGNETIC PARTICLE METHOD 751 The Magnetizing Field 751 Continuous versus Noncontinuous Fields 752 The Inspection Process 753 Demagnetizing the Part 753 APPENDIX A ULTRASONIC PROPERTIES OF COMMON MATERIALS 754 APPENDIX B ELECTRICAL RESISTIVITIES AND CONDUCTIVITIES OF COMMERCIAL METALS AND ALLOYS 759 INTRODUCTION Nondestructive evaluation NDE encompasses those physical and chemical tests that are used to determine if a component or structure can perform its intended function without the test methods impairing the component s performance. Until recently NDE was relegated to detecting physical flaws and estimating their dimensions. These data were used to determine if a component should be scrapped or repaired based on quality-acceptance criteria. Such traditional definitions are being expanded as requirements for high-reliability cost-effective .