Ultrasonic testing
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Ultrasonic testing (UT) is a family of
Ultrasonic testing is often performed on steel and other
History
The first efforts to use ultrasonic testing to detect flaws in solid material occurred in the 1930s.[1] On May 27, 1940, U.S. researcher Dr. Floyd Firestone of the University of Michigan applies for a U.S. invention patent for the first practical ultrasonic testing method. The patent is granted on April 21, 1942 as U.S. Patent No. 2,280,226, titled "Flaw Detecting Device and Measuring Instrument". Extracts from the first two paragraphs of the patent for this entirely new nondestructive testing method succinctly describe the basics of such ultrasonic testing. "My invention pertains to a device for detecting the presence of inhomogeneities of density or elasticity in materials. For instance, if a casting has a hole or a crack within it, my device allows the presence of the flaw to be detected and its position located, even though the flaw lies entirely within the casting and no portion of it extends out to the surface. ... The general principle of my device consists of sending high frequency vibrations into the part to be inspected and the determination of the time intervals of the arrival of the direct and reflected vibrations at one or more stations on the surface of the part."
How it works
In ultrasonic testing, an ultrasound
There are two methods of receiving the ultrasound waveform: reflection and
Features
Advantages
- High penetrating power allows the detection of flaws deep in the part.[1]
- High sensitivity, permitting the detection of extremely small flaws.[1]
- Greater accuracy than other non-destructive methods in determining the depth of internal flaws and the thickness of parts with parallel surfaces.
- Some capability of estimating the size, orientation, shape and nature of defects.
- Some capability of estimating the structure of alloys of components with different acoustic properties
- Non-hazardous to operations or to nearby personnel and has no effect on equipment and materials in the vicinity.
- Capable of portable, highly automated or remote operation.
- Results are immediate, allowing on-the-spot decisions to be made.[1]
- It needs to access only one surface of the product that is being inspected.[1]
Disadvantages
- Manual operation requires careful attention by experienced technicians. The transducers alert to both normal structure of some materials, tolerable anomalies of other specimens (both termed “noise”) and to faults therein severe enough to compromise specimen integrity. These signals must be distinguished by a skilled technician, possibly requiring follow up with other nondestructive testing methods.[5]
- Extensive technical knowledge is required for the development of inspection procedures.[1]
- Rough surface finish, irregular geometry, small parts, thin thicknesses, or un-homogeneous material composition can make testing difficult.
- Surface must be prepared by cleaning and removing loose scale, paint, etc., although paint that is properly bonded to a surface, may not need to be removed.
- Couplants are needed to effectively transfer ultrasonic wave energy between transducers and parts being inspectedEMAT).
- Equipment can be expensive [1]
- Requires reference standards and calibration[1]
Standards
- ISO 2400: Non-destructive testing - Ultrasonic testing - Specification for calibration block No. 1 (2012)
- ISO 7963: Non-destructive testing — Ultrasonic testing — Specification for calibration block No. 2 (2006)
- ISO 10863: Non-destructive testing of welds -- Ultrasonic testing -- Use of time-of-flight diffraction technique (TOFD) (2011)
- ISO 11666: Non-destructive testing of welds — Ultrasonic testing — Acceptance levels (2010)
- ISO 16809: Non-destructive testing -- Ultrasonic thickness measurement (2012)
- ISO 16831: Non-destructive testing -- Ultrasonic testing -- Characterization and verification of ultrasonic thickness measuring equipment (2012)
- ISO 17640: Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment (2010)
- ISO 22825, Non-destructive testing of welds - Ultrasonic testing - Testing of welds in austenitic steels and nickel-based alloys (2012)
- ISO 5577: Non-destructive testing -- Ultrasonic inspection -- Vocabulary (2000)
- EN 583, Non-destructive testing - Ultrasonic examination
- EN 1330-4, Non destructive testing - Terminology - Part 4: Terms used in ultrasonic testing
- EN 12668-1, Non-destructive testing - Characterization and verification of ultrasonic examination equipment - Part 1: Instruments
- EN 12668-2, Non-destructive testing - Characterization and verification of ultrasonic examination equipment - Part 2: Probes
- EN 12668-3, Non-destructive testing - Characterization and verification of ultrasonic examination equipment - Part 3: Combined equipment
- EN 12680, Founding - Ultrasonic examination
- EN 14127, Non-destructive testing - Ultrasonic thickness measurement
(Note: Part of CEN standards in Germany accepted as DIN EN, in Czech Republic as CSN EN.)
See also
- Non-Contact Ultrasound
- Phased array ultrasonics
- Time-of-flight diffraction ultrasonics (TOFD)
- Time-of-flight ultrasonic determination of 3D elastic constants (TOF)
- Internal rotary inspection system (IRIS) ultrasonics for tubes
- EMAT Electromagnetic Acoustic Transducer
- ART (Acoustic Resonance Technology)
References
- ^ a b c d e f g h i j Nondestructive Flaw Detection in Metallic Components Quality magazine August 2015 issue Pages 31-32 by Dan DeVries
- S2CID 39932362.
- .
- ^ https://www.nde-ed.org/EducationResources/CommunityCollege/Ultrasonics/EquipmentTrans/Couplant.htm Couplant Iowa State University - Center for Non-Destructive Evaluation retrieved 8//1/2021
- ^ U.S. Patent 3,260,105 for Ultrasonic Testing Apparatus and Method to James F. McNulty at lines 37-48 and 60-72 of Column 1 and lines 1-4 of Column 2.
Further reading
- Albert S. Birks, Robert E. Green, Jr., technical editors ; Paul McIntire, editor. Ultrasonic testing, 2nd ed. Columbus, OH : ISBN 0-931403-04-9.
- Josef Krautkrämer, Herbert Krautkrämer. Ultrasonic testing of materials, 4th fully rev. ed. Berlin; New York: Springer-Verlag, 1990. ISBN 3-540-51231-4.
- J.C. Drury. Ultrasonic Flaw Detection for Technicians, 3rd ed., UK: Silverwing Ltd. 2004. (See Chapter 1 Archived 2006-10-17 at the Wayback Machine online (PDF, 61 kB)).
- Nondestructive Testing Handbook, Third ed.: Volume 7, Ultrasonic Testing. Columbus, OH: American Society for Nondestructive Testing.
- Detection and location of defects in electronic devices by means of scanning ultrasonic microscopy and the wavelet transform measurement, Volume 31, Issue 2, March 2002, Pages 77–91, L. Angrisani, L. Bechou, D. Dallet, P. Daponte, Y. Ousten
- Charles Hellier (2003). "Chapter 7 - Ultrasonic Testing". Handbook of Nondestructive Evaluation. McGraw-Hill. ISBN 978-0-07-028121-9.