1、Designation: F2004 16Standard Test Method forTransformation Temperature of Nickel-Titanium Alloys byThermal Analysis1This standard is issued under the fixed designation F2004; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 defines procedures for determining thetransformation temperatures of nickel-titanium shape memor
3、yalloys, produced in accordance with Specification F2063,bydifferential scanning calorimetry.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, as
4、sociated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias
5、inASTM Test MethodsE473 Terminology Relating to Thermal Analysis and Rhe-ologyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE967 Test Method for Temperature Calibration of Differen-tial Scanning Calorimeters and Differential Thermal Ana-lyzersE1142 T
6、erminology Relating to Thermophysical PropertiesF2005 Terminology for Nickel-Titanium Shape MemoryAlloysF2063 Specification for Wrought Nickel-Titanium ShapeMemory Alloys for Medical Devices and Surgical Im-plantsF2082 Test Method for Determination of TransformationTemperature of Nickel-Titanium Sha
7、pe Memory Alloysby Bend and Free Recovery3. Terminology3.1 Specific technical terms used in this test method arefound in Terminologies E473, E1142, and F2005.4. Summary of Test Method4.1 This test method involves heating and cooling a testspecimen at a controlled rate in a controlled environmentthro
8、ugh the temperature interval of the phase transformation.The difference in heat flow between the test material and areference material due to energy changes is continuouslymonitored and recorded. Absorption of energy due to a phasetransformation in the specimen results in an endothermic peakon heati
9、ng. Release of energy due to a phase transformation inthe specimen results in an exothermic peak on cooling.5. Significance and Use5.1 Differential scanning calorimetry provides a rapidmethod for determining the transformation temperature(s) ofnickel-titanium shape memory alloys.5.2 This test method
10、 uses small, stress-free, annealedsamples to determine whether a sample of nickel-titanium alloycontaining nominally 54.5 to 56.5 % nickel by weight isaustenitic or martensitic at a particular temperature. Sincechemical analysis of these alloys does not have sufficientprecision to determine the tran
11、sformation temperature bymeasuring the nickel-to-titanium ratio of the alloy, directmeasurement of the transformation temperature of an annealedsample of known thermal history is recommended.5.3 This test method is useful for quality control, specifica-tion acceptance, and research.5.4 Transformatio
12、n temperatures derived from differentialscanning calorimetry (DSC) may not agree with those obtainedby other test methods due to the effects of strain and load on thetransformation. For example, transformation temperaturesmeasured in accordance with Test Method F2082 will differfrom those measured b
13、y the current standard.5.5 The use of this test method for finished or semi-finishedcomponents without annealing (as in 8.2) shall be agreed uponbetween the purchaser and the supplier.1This test method is under the jurisdiction of ASTM Committee F04 on Medicaland Surgical Materials and Devices and i
14、s the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved Dec. 1, 2016. Published January 2017. Originallyapproved in 2000. Last previous edition approved in 2010 as F2004 05 (2010).DOI: 10.1520/F2004-16.2For referenced ASTM standards, visit the ASTM website
15、, 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesTh
16、is international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (
17、TBT) Committee.16. Interferences6.1 Make sure the material to be tested is homogeneoussince milligram sample quantities are used.6.2 Take care in preparing the sample (1). Cutting andgrinding can cause localized heating and/or deformation, thataffect the transformation temperature. Oxidation during
18、heattreatment can change the thermal conductance of the sample.6.3 Set the gas flow to provide adequate thermal conductiv-ity in the test cell.7. Apparatus7.1 Use a differential scanning calorimeter capable of heat-ing and cooling at rates up to 10C/min and of automaticallyrecording the differential
19、 energy input between the specimenand the reference to the required sensitivity and precision.7.2 Use sample capsules or pans composed of aluminum orother inert material of high thermal conductivity.7.3 Use helium gas purge supply. See 10.3.1.7.4 Use an analytical balance with a capacity of 100 mgca
20、pable of weighing to the nearest 0.1 mg.8. Sampling8.1 Use a sample size of 25 to 45 mg. Cut the sample tomaximize surface contact with the (DSC) sample pan.8.2 Anneal the sample at 800 to 850C for 15 to 60 min invacuum or inert atmosphere, or in air with adequate protectionfrom oxidation. Rapidly c
21、ool the sample to prevent precipita-tion of phases that may change the transformation temperatureof the alloy. For example, bare 25-45 mg samples can be aircooled after solution annealing.8.3 Clean the sample of all foreign materials such as cuttingfluid. If the sample is oxidized during heat treatm
22、ent, grind,polish, or etch the sample to remove the oxide. Take care toavoid cold working the sample as this will change its thermalresponse. Slight oxidation is permissible but remove all heavyoxide scale.9. Calibration9.1 Calibrate the temperature axis of the instrument usingthe same heating rate,
23、 purge gas, and flow rate as those used foranalyzing the specimen in accordance with Test Method E967.10. Procedure10.1 Place the sample on the sample pan and place the panon the test pedestal.10.2 Place an empty pan on the reference pedestal.10.3 Turn on the purge gas at a flow rate of 10 to 50mL/m
24、in.10.3.1 Use helium as the purge gas for the sample chamber.10.3.2 Use a dry air, helium, or nitrogen cover gas. The drygas shall have a dew point below the lowest temperature of thecooling cycle.10.4 Run the cooling and heating program.10.4.1 Use the heating and cooling rates of 10 6 0.5C/min.10.4
25、.2 Heat the sample from room temperature to a tem-perature of at least Af+ 30C; hold at that temperature for atime sufficient to equilibrate the sample with the furnace.10.4.3 Cool the sample to a temperature of below Mf30C; hold for a time sufficient to equilibrate the sample withthe furnace. Then,
26、 heat the sample to a temperature of at leastAf+ 30C.10.5 Data AcquisitionRecord the resulting curve from theheating and cooling program from Af+ 30C to Mf 30C.11. Graphical Data Reduction11.1 Draw the baselines for the cooling and heating portionsof the curve as shown in Fig. 1.11.2 Draw the tangen
27、ts to the cooling and heating spikesthrough the inflection points as shown in Fig. 1. If a computerprogram is used to construct the tangents, care must be taken inlocating the tangent points.11.3 Obtain Ms,Mf,As, and Afas the graphical intersectionof the baseline with the extension of the line of ma
28、ximuminclination of the appropriate peak of the curve as shown inFig. 1.Apis the peak minimum of the endothermic curve, andMpis the peak maximum of the exothermic curve. ReadApandMpdirectly from the graph as shown in Fig. 1.12. Report12.1 Report the following information with the test results:12.1.1
29、 Complete identification and description of the mate-rial tested including the specification and lot number.12.1.2 Description of the instrument used for the test.12.1.3 Statement of mass, dimensions, and geometry.12.1.4 Material for the specimen pan and temperature pro-gram.12.1.5 Description of th
30、e temperature calibration procedure.12.1.6 Identification of the specimen environment by gas,flow rate, purity, and composition.12.1.7 Results of the transformation measurements usingthe nomenclature in accordance with Terminology F2005.Temperature results should be reported to the nearest 1C.FIG. 1
31、 DSC Curve for Nickel-Titanium (NiTi)F2004 16213. Precision and Bias13.1 An interlaboratory study was conducted in accordancewith Practice E691 in seven laboratories with three differentmaterials, with each laboratory obtaining five results for eachmaterial. There were two rounds of testing. In the
32、first round,all the test samples were annealed in one laboratory; in thesecond round, the samples were annealed by the laboratory thatconducted the test. The details are given in ASTM ResearchReport No. RR:F04-1008.313.2 The results of round one are summarized in Tables 1-6for each transformation te
33、mperature parameter (Mf,Mp,Ms,As,Ap,Af). The values are in degrees Celsius. The termsrepeatability limit and reproducibility limit are used as speci-fied in Practice E177.13.3 The results of round two are summarized in Tables7-12 for each transformation temperature parameter (Mf,Mp,Ms,As,Ap,Af). The
34、 values are in degrees Celsius. The termsrepeatability limit and reproducibility limit are used as speci-fied in Practice E177.14. Keywords14.1 differential scanning calorimeter; DSC; nickel-titaniumalloy; NiTi; Nitinol; shape memory alloy; TiNi; transformationtemperature3Supporting data have been f
35、iled at ASTM International Headquarters and maybe obtained by requesting Research Report RR:F04-1008. Contact ASTM CustomerService at serviceastm.org.TABLE 1 Precision of MfMaterialMf,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -50.0
36、 0.57 3.97 1.6 11.1B -26.3 0.95 2.62 2.7 7.3C 48.5 1.02 1.54 3.0 4.3TABLE 2 Precision of MpMaterialMp,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -43.8 0.42 2.65 1.2 7.4B -20.5 1.10 2.21 3.1 6.2C 58.1 0.88 1.05 2.5 2.9TABLE 3 Precisi
37、on of MsMaterialMs,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -41.6 0.40 2.35 1.1 6.6B -16.9 0.95 1.24 2.7 3.5C 64.8 0.74 1.15 2.1 3.2TABLE 4 Precision of AsMaterialAs,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDe
38、viationRepeatabilityLimitReproducibilityLimitA -25.3 0.30 1.85 0.8 5.2B -4.8 0.32 1.58 0.9 4.4C 72.9 0.65 2.68 1.8 7.5TABLE 5 Precision of ApMaterialAp,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -23.4 0.23 2.01 0.6 5.6B 2.5 0.67 1.3
39、9 1.9 3.9C 91.6 0.80 2.25 2.2 6.3F2004 163TABLE 6 Precision of AfMaterialAf,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -19.4 0.16 1.94 0.5 5.4B 5.7 0.57 1.50 1.6 4.2C 94.7 0.85 3.18 2.4 8.9TABLE 7 Precision of Mf, When Samples are A
40、nnealed by TestingLaboratoryMaterialMf,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -49.1 2.03 8.49 5.7 23.8B -27.3 1.85 5.93 5.2 16.6C 48.5 1.23 1.84 3.4 5.1TABLE 8 Precision of Mp, When Samples are Annealed byTesting LaboratoryMater
41、ialMp,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -43.0 1.31 8.69 3.7 24.3B -21.5 1.67 7.31 4.7 20.5C 58.1 1.31 1.47 3.7 4.1TABLE 9 Precision of Ms, When Samples are Annealed byTesting LaboratoryMaterialMs,grandmeanRepeatabilityStand
42、ardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -40.7 2.84 8.29 7.9 23.2B -18.9 2.38 6.60 6.7 18.5C 64.8 1.39 2.29 3.9 6.4TABLE 10 Precision of As, When Samples are Annealed byTesting LaboratoryMaterialAs,grandmeanRepeatabilityStandardDeviationReproducibilityStand
43、ardDeviationRepeatabilityLimitReproducibilityLimitA -23.2 0.94 5.26 2.6 14.7B -4.1 0.52 1.93 1.4 5.4C 72.9 0.70 2.80 2.0 7.8TABLE 11 Precision of Ap, When Samples are Annealed byTesting LaboratoryMaterialAp,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitRepr
44、oducibilityLimitA -19.1 0.56 5.30 1.6 14.8B 2.2 0.65 2.71 1.8 7.6C 89.5 1.01 3.37 2.8 9.4F2004 164APPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 It is well known that slow cooling after annealing ofnickel-rich alloys allows precipitates of the Ni4Ti3type toform, thereby increasing the Ti conten
45、t of the matrix and thetransformation temperatures. The practice is to avoid slowcooling and thus preserve the “as annealed” transformation. Itis possible, however, to cool the samples too quickly, raisingthe transformation temperature, possibly due to stress effectsthat retain residual martensite.
46、One method of achieving thedesired cooling rate is to heat treat the test specimens on a foiltray and then allow the samples and the foil tray to cooltogether, out of the furnace, in room temperature air.X1.2 Differences in sample preparation techniques betweenlaboratories influenced the reproducibi
47、lity limit. Differences incalibration techniques may have also influenced reproducibil-ity. To minimize interlaboratory variations in results, commonsample preparation and calibration practices must be estab-lished.REFERENCE(1) Marquez, J., Slater, T., and Sczerzenie, F., “Determining the Trans-form
48、ation Temperatures of NiTi Alloys using Differential ScanningCalorimetry,” in Proceedings of the 2nd International Conference onShape Memory and Superelastic Technologies (SMST), edited byA. R.Pelton, D. Hodgson, S. M. Russell, and T. Duerig, 1997, pp. 13-18.ASTM International takes no position resp
49、ecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should
