ASTM_F_2005_-_05_2015.pdf

Designation:F200505(Reapproved 2015)Standard Terminology forNickel-Titanium Shape Memory Alloys1This standard is issued under the fixed designation F2005;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 terminology is a compilation of definitions of termsused in ASTM documents relating to nickel-titanium shapememory alloys used for medical devices.This terminologyincludes only those terms for whichASTM either has standardsor which are used inASTM standards for nickel-titanium shapememory alloys.It is not intended to be an all-inclusive list ofterms related to shape memory alloys.1.2 Definitions that are similar to those published by anotherstandards body are identified with abbreviations of the name ofthat organization;for example,ICTAC is the InternationalConfederation for Thermal Analysis and Calorimetry.2.Referenced Documents2.1 ASTM Standards:2E7 Terminology Relating to MetallographyE473 Terminology Relating to Thermal Analysis and Rhe-ologyF2004 Test Method for Transformation Temperature ofNickel-Titanium Alloys by Thermal AnalysisF2082 Test Method for Determination of TransformationTemperature of Nickel-Titanium Shape Memory Alloysby Bend and Free Recovery(Withdrawn 2015)33.Terminologyactive austenite finish temperature,nterm used to denoteaustenite finish temperature of a finished wire,tube,orcomponent as determined by a bend and free recoverymethod rather than by DSC.alloy phase,nin a shape memory alloy,the crystal structurestable at a particular temperature and stress.anneal,vto heat treat in order to remove the effect ofcold-working.austenite,nthe high temperature parent phase in Ni-Ti shapememory alloys with a B2 crystal structure.This phasetransforms to R-phase or martensite on cooling.austenite finish temperature(Af),nthe temperature atwhich the martensite to austenite transformation is com-pleted on heating in a single-stage transformation(Fig.1)orthe temperature at which the R-phase to austenite transfor-mation is completed on heating in a two-stage transforma-tion(Fig.2).austenite peak temperature(Ap),nthe temperature of theendothermic peak position on the differential scanningcalorimeter(DSC)curve upon heating for the martensite toaustenite transformation in a single-stage transformation(Fig.1)or the temperature of the endothermic peak positionon the DSC curve upon heating for the R-phase to austenitetransformation in a two-stage transformation(Fig.2).austenite start temperature(As),nthe temperature atwhich the martensite to austenite transformation begins onheating in a single-stage transformation(Fig.1)or thetemperature at which the R-phase to austenite transformationbegins on heating in a two-stage transformation(Fig.2).bend and free recovery(BFR),na test method for deter-mining austenite transformation temperatures on heating.DISCUSSIONThe test involves cooling a wire or tube specimenbelow the Mftemperature,deforming the specimen in a controlledfashion,then heating through the austenite transformation.By measur-ing the shape memory response of the specimen Asand Af,tempera-tures can be determined.This test method is covered in Test MethodF2082.differential scanning calorimeter(DSC),na device that iscapable of heating a test specimen and a reference at acontrolled rate and of automatically measuring the differencein heat flow between the specimen and the reference both tothe required sensitivity and precision.differential scanning calorimetry(DSC),na technique inwhich the difference in heat flow into or out of a substanceand an inert reference is measured as a function of tempera-ture while the substance and the reference material aresubjected to a controlled temperature program.This test1This terminology is under the jurisdiction ofASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.12 on Metallurgical Materials.Current edition approved March 1,2015.Published May 2015.Originallyapproved in 2000.Last previous edition approved in 2010 as F2005 05(2010).DOI:10.1520/F2005-05R15.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 method,as it applies to Ni-Ti shape memory alloys,iscovered in Test Method F2004.(E473)(ICTAC(International Confederation for Ther-mal Analysis and Calorimetry)(1993)free recovery,nunconstrained motion of a shape memoryalloy upon heating and transformation to austenite afterdefor