Development of nondestructive-evaluation techniques for high-temperature ceramic heat-exchanger components. Fourth annual report, October 1980-September 1981

Technical Report · Fri Jan 01 00:00:00 EST 1982

OSTI ID:5222998

Kupperman, D S; Yuhas, D

An assessment has been made of ultrasonic techniques developed to date for nondestructive evaluation of SiC heat-exchanger tubes. The results suggest that ultrasonic inspection is a useful and valuable technique for inspecting these tubes, including ceramic butt joints. However, this method alone is currently not sufficiently effective to detect all critical flaws because of (a) the difficulties in following the surface of an out-of-round tube; (b) the high velocity and thus the large angle of refraction of sound in SiC, which for small-diameter tubes leads to significant beam distortion; and (c) insuffient resolution, relative to the small critical flaw size in ceramics, at conventional ultrasonic testing frequencies. The experiments show that higher frequencies (up to 35 MHz) are required for effective wall-thickness measurements and detection of laminar-type flaws. While acoustic microscopy techniques for flaw and material characterization and holographic interferometry for crack sizing can be used for preservice inspection, in-service inspection of heat-exchanger tubes will probably be limited to ultrasonic inspection from the bore side. Acoustic microscopy (for flaw and material characterization) and holographic interferometry (for crack sizing), although not adaptable to boreside inspection, were shown to be effective as complementary or confirmatory techniques when used in conjunction with conventional ultrasonic testing. Preliminary results employing the microfocus radiogaphy technique have indicated that this method is more sensitive than conventional radiographic techniques for ceramic butt joint assessment.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 5222998
• Report Number(s): ANL/FE-82-2; ON: DE82012603
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
36 MATERIALS SCIENCE
HEAT EXCHANGERS
DEFECTS
INDUSTRIAL RADIOGRAPHY
NONDESTRUCTIVE TESTING
CERAMICS
DETECTION
EXPERIMENTAL DATA
HOLOGRAPHY
INSPECTION
SILICON CARBIDES
TUBES
ULTRASONIC WAVES
CARBIDES
CARBON COMPOUNDS
DATA
INFORMATION
MATERIALS TESTING
NUMERICAL DATA
SILICON COMPOUNDS
SOUND WAVES
TESTING
420400* - Engineering- Heat Transfer & Fluid Flow
360200 - Ceramics
Cermets
& Refractories