1、Designation: F2005 05 (Reapproved 2010)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
2、. 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
3、 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
4、 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 Relatin
5、g 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 Alloys byBend and Free Recovery3. Terminologyactive austenite finish temper
6、ature, 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 t
7、o 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
8、 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 sc
9、anningcalorimeter (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).austeni
10、te start temperature (As), nthe temperature atwhich the martensite to austenite transformation begins onheating in a single-stage transformation (Fig. 1)orthetemperature at which the R-phase to austenite transformationbegins on heating in a two-stage transformation (Fig. 2).bend and free recovery (B
11、FR), 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 r
12、esponse 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 flo
13、w 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 refe
14、rence 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 Dec. 1, 2
15、010. Published February 2011. Originallyapproved in 2000. Last previous edition approved in 2005 as F2005 05. DOI:10.1520/F2005-05R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume info
16、rmation, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.method, as it applies to Ni-Ti shape memory alloys, iscovered in Test Method F2004.(E473) (ICTAC (International
17、Confederation for ThermalAnalysis and Calorimetry) (1993)free recovery, nunconstrained motion of a shape memoryalloy upon heating and transformation to austenite afterdeformation below the austenite phase.linear elasticity, nlinear recoverable deformation behavior.DISCUSSIONNo significant phase tran
18、sformation event occurs whilestraining the material and the tensile load-extension or stress-strain plotis linear upon loading and unloading.lower plateau strength (LPS), nthe stress at 2.5 % strainduring tensile unloading of the sample, after loading to 6 %strain.martensite, nthe lowest temperature
19、 phase in Ni-Ti shapememory alloys with a B198 (B19 prime) monoclinic crystalstructure.martensite deformation temperature (Md), nthe highesttemperature at which martensite will form from the austenitephase in response to an applied stress.martensite finish temperature (Mf), nthe temperature atwhich
20、the transformation from austenite to martensite iscompleted on cooling in a single-stage transformation (Fig.1) or the temperature at which the transformation fromR-phase to martensite is completed on cooling in a two-stagetransformation (Fig. 2).martensite peak temperature (Mp), nthe temperature of
21、the exothermic peak position on the DSC curve upon coolingfor the austenite to martensite transformation (Fig. 1)ortheR-phase to martensite transformation (Fig. 2).martensite start temperature (Ms), nthe temperature atwhich the transformation from austenite to martensite beginson cooling in a single
22、-stage transformation (Fig. 1)orthetemperature at which the transformation from R-phase tomartensite begins on cooling in a two-stage transformation(Fig. 2).nitinol, na generic name for a Ni-Ti alloy.pseudoelasticity, nSee superelasticity.R-phase, nthe intermediate phase which may form betweenausten
23、ite and martensite.DISCUSSIONThis occurs in Ni-Ti shape memory alloys under certainconditions. The crystal lattice of the R-Phase is a rhombohedraldistortion of the cubic austenite crystal lattice structure, hence the name“R-phase.”R-phase finish temperature (Rf), nthe temperature atwhich the transf
24、ormation from austenite to R-phase iscompleted on cooling in a two-stage transformation (Fig. 2).R-phase peak temperature (Rp), nthe temperature of theexothermic peak position on the DSC curve upon cooling forthe austenite to R-phase transformation (Fig. 2).R-phase start temperature (Rs), nthe tempe
25、rature at whichthe transformation from austenite to R-phase begins oncooling in a two-stage transformation (Fig. 2).R*-phase finish temperature (R*f), nthe temperature atwhich the martensite to R-phase transformation is completedon heating in a two-stage transformation (Fig. 2).R*-phase peak tempera
26、ture (R*p), nthe temperature of theendothermic peak position on the DSC curve upon heating,for the martensite to R-phase transformation in a two-stagetransformation (Fig. 2).R*-phase start temperature (R*s), ntemperature at whichthe martensite to R-phase transformation begins on heatingin a two-stag
27、e transformation (Fig. 2).residual elongation (Elr%), nthe strain after tensile load-ing to 6 % strain and unloading to 7 MPa.shape memory alloy, na metal which, after an apparentplastic deformation in the martensitic phase, undergoes aFIG. 1 DSC Graph for a Single-Stage TransformationFIG. 2 DSC Gra
28、ph for a Two-Stage TransformationF2005 05 (2010)2thermoelastic change in crystal structure when heatedthrough its transformation temperature range, resulting in arecovery of the deformation.solution anneal, solution heat treatment, vto heat treat inorder to remove precipitates.superelasticity, nnonl
29、inear recoverable deformation behav-ior of Ni-Ti shape memory alloys at temperatures above theaustenite finish temperature (Af). Pseudoelasticity is some-times used for superelasticity.DISCUSSIONThe nonlinear deformation arises from the stress-induced formation of martensite on loading and the spont
30、aneousreversion of this crystal structure to austenite upon unloading.thermoelastic martensitic transformation, na diffusion-less thermally reversible phase change characterized by achange in crystal structure.DISCUSSIONThis is a process in which an incremental change intemperature produces a propor
31、tionate increase or decrease in theamount of phase change.transformation temperature range, nin a shape memoryalloy, the temperature range in which a change of phaseoccurs. (E7) (1988)upper plateau strength (UPS), nthe stress at 3% strainduring tensile loading of the sample.ASTM International takes
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