ASTM_C_1332_-_01_2013.pdf

Designation:C133201(Reapproved 2013)Standard Test Method forMeasurement of Ultrasonic Attenuation Coefficients ofAdvanced Ceramics by Pulse-Echo Contact Technique1This standard is issued under the fixed designation C1332;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method describes a procedure for measurementof ultrasonic attenuation coefficients for advanced structuralceramic materials.The procedure is based on a broadbandbuffered piezoelectric probe used in the pulse-echo contactmode and emitting either longitudinal or shear waves.Theprimary objective of this test method is materials characteriza-tion.1.2 The procedure requires coupling an ultrasonic probe tothe surface of a plate-like sample and the recovery of succes-sive front surface and back surface echoes.Power spectra ofthe echoes are used to calculate the attenuation spectrum(attenuation coefficient as a function of ultrasonic frequency)for the sample material.The transducer bandwidth and spectralresponse are selected to cover a range of frequencies andcorresponding wavelengths that interact with microstructuralfeatures of interest in solid test samples.1.3 The purpose of this test method is to establish funda-mental procedures for measurement of ultrasonic attenuationcoefficients.These measurements should distinguish and quan-tify microstructural differences among solid samples andtherefore help establish a reference database for comparingmaterials and calibrating ultrasonic attenuation measurementequipment.1.4 This test method applies to monolithic ceramics and alsopolycrystalline metals.This test method may be applied towhisker reinforced ceramics,particulate toughened ceramics,and ceramic composites provided that similar constraints onsample size,shape,and finish are met as described herein formonolithic ceramics.1.5 This test method sets forth the constraints on samplesize,shape,and finish that will assure valid attenuationcoefficient measurements.This test method also describes theinstrumentation,methods,and data processing procedures foraccomplishing the measurements.1.6 This test method is not recommended for highly attenu-ating materials such as very thick,very porous,rough-surfacedmonolithics or composites.This test method is not recom-mended for highly nonuniform,heterogeneous,cracked,defective,or otherwise flaw-ridden samples that are unrepre-sentative of the nature or inherent characteristics of thematerial under examination.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C1331 Test Method for Measuring Ultrasonic Velocity inAdvanced Ceramics with Broadband Pulse-Echo Cross-Correlation MethodE664 Practice for the Measurement of the Apparent Attenu-ation of Longitudinal Ultrasonic Waves by ImmersionMethodE1316 Terminology for Nondestructive ExaminationsE1495 Guidefor Acousto-Ultrasonic AssessmentofComposites,Laminates,and Bonded Joints2.2 ASNT Document:Recommended Practice SNT-TC-1A for NondestructiveTesting Personnel Qualification and Certification32.3 Military Standard:MIL-STD-410 Nondestructive Testing Personnel Qualifica-tion and Certification41This test method is under the jurisdiction of ASTM Committee C28 onAdvanced Ceramics and is the direct responsibility of Subcommittee C28.03 onPhysical Properties and Non-Destructive Evaluation.Current edition approved Feb.1,2013.Published April 2013.Originallyapproved in 1996.Last previous edition approved in 2007 as C1332 01(2007).DOI:10.1520/C1332-01R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available fromAmerican Society for Nondestructive Testing(ASNT),P.O.Box28518,1711 Arlingate Ln.,Columbus,OH 43228-0518,http:/www.asnt.org.4Available from Standardization Documents Order Desk,DODSSP,Bldg.4,SectionD,700RobbinsAve.,Philadelphia,PA19111-5098,http:/www.dodssp.daps.mil.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 2.4 Additional references are cited in the text and at end ofthis test method.3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 acoustic impedance(Z)a property(1)5defined by amaterials density,p,and the velocity of sound within it,v,where Z=v.3.1.2 attenuation coeffcient()decrease in ultrasoundintensity with distance expressed in nepers(Np)per unitlength,herein,=ln(I0/I)/