ASTM C1331-96

Standard Test Method for Measuring Ultrasonic Velocity in Advanced Ceramics with Broadband Pulse-Echo Cross-Correlation Method

SCOPE
1.1 This test method describes a procedure for measurement of ultrasonic velocity in structural engineering solids such as monolithic ceramics, toughened ceramics, and ceramic matrix composites.  
1.2 This test method is based on the broadband pulse-echo contact ultrasonic method. The procedure involves a computer-implemented, frequency-domain method for precise measurement of time delays between pairs of echoes returned by the back surface of a test sample or part.  
1.3 This test method describes a procedure for using a digital cross-correlation algorithm for velocity measurement. The cross-correlation function yields a time delay between any two echo waveforms (1).

General Information

• Status: Historical
• Publication Date: 09-May-2001
• ICS: 19.100 - Non-destructive testing
• ICS: 81.060.99 - Other standards related to ceramics
• Technical Committee: C28 - Advanced Ceramics

Relations

• Replaced By: ASTM C1331-01 - Standard Test Method for Measuring Ultrasonic Velocity in Advanced Ceramics with Broadband Pulse-Echo Cross-Correlation Method
• Effective Date: 10-May-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: C 1331 – 96
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Measuring Ultrasonic Velocity in Advanced Ceramics with
1
Broadband Pulse-Echo Cross-Correlation Method
This standard is issued under the fixed designation C 1331; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 2.4 Additional references are cited in the text and at end of
this document.
1.1 This test method describes a procedure for measurement
of ultrasonic velocity in structural engineering solids such as
3. Terminology
monolithic ceramics, toughened ceramics, and ceramic matrix
3.1 Descriptions of Terms Specific to This Standard:
composites.
1.2 This test method is based on the broadband pulse-echo 3.1.1 back surface—the surface of a test sample which is
contact ultrasonic method. The procedure involves a computer- opposite to the front surface and from which back surface
implemented, frequency-domain method for precise measure- echoes are returned at normal incidence directly to the trans-
ment of time delays between pairs of echoes returned by the
ducer.
back surface of a test sample or part. 3.1.2 bandwidth—the frequency range of an ultrasonic
1.3 This test method describes a procedure for using a
probe, defined by convention as the difference between the
digital cross-correlation algorithm for velocity measurement. lower and upper frequencies at which the signal amplitude is 6
The cross-correlation function yields a time delay between any
dB down from the frequency at which maximum signal
2
two echo waveforms 1. amplitude occurs.
3.1.3 broadband transducer—an ultrasonic transducer ca-
2. Referenced Documents
pable of sending and receiving undistorted signals over a broad
bandwidth, consisting of a thin damped piezocrystal in a
2.1 ASTM Standards:
B 311 Test Method for Density Determination for Powder buffered probe (search unit).
Metallurgy (P/M) Materials Containing Less Than Two 3.1.4 buffered probe—an ultrasonic search unit as defined in
3
Percent Porosity Terminology E 1316 but containing a delay line, or buffer rod,
to which the piezocrystal is affixed within the search unit
C 373 Test Method for Water Absorption, Bulk Density,
Apparent Porosity, and Apparent Specific Gravity of Fired housing and which separates the piezocrystal from the test
4
sample (Fig. 1).
Whiteware Products
E 494 Practice for Measuring Ultrasonic Velocity in Mate- 3.1.5 buffer rod—an integral part of a buffered probe,
5
rials usually a quartz or fused silica cylinder that provides a time
5
E 1316 Terminology for Nondestructive Examinations delay between the excitation pulse from the piezocrystal and
2.2 ASNT Document: echoes returning from a sample coupled to the free end of the
buffer rod.
Recommended Practice SNT-TC-1A for Nondestructive
6
Testing Personnel Qualification and Certification 3.1.6 cross-correlation function—the cross-correlation
2.3 Military Standard: function, implemented by a digital algorithm, yields a time
delay between any two (ultrasonic) echo waveforms. This time
MIL-STD-410 Nondestructive Testing Personnel Qualifica-
7
is used to determine velocity (1).
tion and Certification
3.1.7 dispersion—variation of ultrasonic velocity as a func-
tion of wavelength, that is, frequency dependence of velocity.
1
This test method is under the jurisdiction of ASTM Committee C-28 on
3.1.8 front surface—the surface of a test sample to which
Advanced Ceramics and is the direct responsibility of Subcommittee C28.02 on
the buffer rod is coupled at normal incidence (designated as test
Design and Evaluation.
Current edition approved March 10, 1996. Published May 1996. surface in Terminology E 1316.
2
The boldface numbers in parentheses refer to the list of references at the end of
3.1.9 group velocity—velocity of a broadband ultrasonic
this test method.
pulse consisting of many different component wavelengths.
3
Annual Book of ASTM Standards, Vol 02.05.
4
3.1.10 test sample—a solid coupon or material part that
Annual Book of ASTM Standards, Vol 15.02.
5
Annual Book of ASTM Standards, Vol 03.03.
meets the constraints needed to make the ultrasonic velocity
6
Available from the American Society for Nondestructive Testing, 1711 Arlin-
measurements described herein, that is, a test sample or part
gate Ln., Columbus, OH 43228.
7 having flat, parallel, smooth, preferably ground or polished
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
Robbins Ave., Philadelphia, PA 19111-5094, Attn:
...