1、Designation: F2004 16F2004 17Standard 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,
2、 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 defines procedures for determining the transformation temperatures of nickel-titanium sh
3、ape memoryalloys, produced in accordance with Specification F2063, by differential scanning calorimetry.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concer
4、ns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and to determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in accord
5、ance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Sta
6、ndards:2E177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE473 Terminology Relating to Thermal Analysis and RheologyE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE967 Test Method for Temperature Calibration of Differential Sc
7、anning Calorimeters and Differential Thermal AnalyzersE1142 Terminology Relating to Thermophysical PropertiesF2005 Terminology for Nickel-Titanium Shape Memory AlloysF2063 Specification for Wrought Nickel-Titanium Shape Memory Alloys for Medical Devices and Surgical ImplantsF2082 Test Method for Det
8、ermination of Transformation Temperature of Nickel-Titanium Shape Memory Alloys by Bend andFree Recovery3. Terminology3.1 Specific technical terms used in this test method are found in Terminologies E473, E1142, and F2005.4. Summary of Test Method4.1 This test method involves heating and cooling a t
9、est specimen at a controlled rate in a controlled environment through thetemperature interval of the phase transformation. The difference in heat flow between the test material and a reference material dueto energy changes is continuously monitored and recorded. Absorption of energy due to a phase t
10、ransformation in the specimenresults in an endothermic peak on heating. Release of energy due to a phase transformation in the specimen results in an exothermicpeak on cooling.5. Significance and Use5.1 Differential scanning calorimetry provides a rapid method for determining the transformation temp
11、erature(s) of nickel-titanium shape memory alloys.1 This test method is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved Dec. 1, 2016Oct. 1, 2017. Publis
12、hed January 2017October 2017. Originally approved in 2000. Last previous edition approved in 20102016 asF2004 05 (2010).F2004 16. DOI: 10.1520/F2004-16.10.1520/F2004-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual
13、 Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be te
14、chnically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, P
15、O Box C700, West Conshohocken, PA 19428-2959. United States15.2 This test method uses small, stress-free, annealed samples to determine whether a sample of nickel-titanium alloy containingnominally 54.5 to 56.5 %57.0 % nickel by weight is austenitic or martensitic at a particular temperature. Since
16、chemical analysisof these alloys does not have sufficient precision to determine the transformation temperature by measuring the nickel-to-titaniumratio of the alloy, direct measurement of the transformation temperature of an annealed sample of known thermal history isrecommended.5.3 This test metho
17、d is useful for quality control, specification acceptance, and research.5.4 Transformation temperatures derived from differential scanning calorimetry (DSC) may not agree with those obtained byother test methods due to the effects of strain and load on the transformation. For example, transformation
18、 temperatures measuredin accordance with Test Method F2082 will differ from those measured by the current standard.5.5 The use of this test method for finished or semi-finished components without annealing (as in 8.2) shall be agreed uponbetween the purchaser and the supplier.6. Interferences6.1 Mak
19、e sure the material to be tested is homogeneous since milligram sample quantities are used.6.2 Take care in preparing the sample (1). Cutting and grinding can cause localized heating and/or deformation, that affect thetransformation temperature. Oxidation during heat treatment can change the thermal
20、 conductance of the sample.6.3 Set the gas flow to provide adequate thermal conductivity in the test cell.7. Apparatus7.1 Use a differential scanning calorimeter capable of heating and cooling at rates up to 10C/min and of automaticallyrecording the differential energy input between the specimen and
21、 the reference to the required sensitivity and precision.7.2 Use sample capsules or pans composed of aluminum or other 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 mg capable of weighing to the nearest 0.
22、1 mg.8. Sampling8.1 Use a sample size of 25 to 45 mg. Cut the sample to maximize surface contact with the (DSC) sample pan.8.2 Anneal the sample at 800 to 850C for 15 to 60 min in vacuum or inert atmosphere, or in air with adequate protection fromoxidation. Rapidly cool the sample to prevent precipi
23、tation of phases that may change the transformation temperature of the alloy.For example, bare 25-45 mg samples can be air cooled after solution annealing.8.3 Clean the sample of all foreign materials such as cutting fluid. If the sample is oxidized during heat treatment, grind, polish,or etch the s
24、ample to remove the oxide. Take care to avoid cold working the sample as this will change its thermal response. Slightoxidation is permissible but remove all heavy oxide scale.9. Calibration9.1 Calibrate the temperature axis of the instrument using the same heating rate, purge gas, and flow rate as
25、those used foranalyzing the specimen in accordance with Test Method E967.FIG. 1 DSC Curve for Nickel-Titanium (NiTi)F2004 17210. Procedure10.1 Place the sample on the sample pan and place the pan on the test pedestal.10.2 Place an empty pan on the reference pedestal.10.3 Turn on the purge gas at a f
26、low rate of 10 to 50 mL/min.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 dry gas 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 r
27、ates of 10 6 0.5C/min.10.4.2 Heat the sample from room temperature to a temperature of at least Af + 30C; hold at that temperature for a timesufficient to equilibrate the sample with the furnace.10.4.3 Cool the sample to a temperature of below Mf 30C; hold for a time sufficient to equilibrate the sa
28、mple with thefurnace. Then, heat the sample to a temperature of at least Af + 30C.10.5 Data AcquisitionRecord the resulting curve from the heating and cooling program from Af + 30C to Mf 30C.11. Graphical Data Reduction11.1 Draw the baselines for the cooling and heating portions of the curve as show
29、n in Fig. 1.11.2 Draw the tangents to the cooling and heating spikes through the inflection points as shown in Fig. 1. If a computer programis used to construct the tangents, care must be taken in locating the tangent points.11.3 Obtain Ms, Mf, As, and Af as the graphical intersection of the baselin
30、e with the extension of the line of maximuminclination of the appropriate peak of the curve as shown in Fig. 1. Ap is the peak minimum of the endothermic curve, and Mp isthe peak maximum of the exothermic curve. Read Ap and Mp directly from the graph as shown in Fig. 1.12. Report12.1 Report the foll
31、owing information with the test results:12.1.1 Complete identification and description of the material 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
32、temperature program.12.1.5 Description of the 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 using the nomenclature in accordance with Terminology F2005.Temperature resul
33、ts should be reported to the nearest 1C.13. Precision and Bias13.1 An interlaboratory study was conducted in accordance with Practice E691 in seven laboratories with three differentmaterials, with each laboratory obtaining five results for each material. There were two rounds of testing. In the firs
34、t round, all thetest samples were annealed in one laboratory; in the second round, the samples were annealed by the laboratory that conductedthe test. The details are given in ASTM Research Report No. RR:F04-1008.313.2 The results of round one are summarized in Tables 1-6 for each transformation tem
35、perature parameter (Mf, Mp, Ms, As,Ap, Af). The values are in degrees Celsius. The terms repeatability limit and reproducibility limit are used as specified in PracticeE177.3 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:F04-1
36、008. Contact ASTM CustomerService at serviceastm.org.TABLE 1 Precision of MfMaterialMf,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -50.0 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 4.3F2004 17313.3 The results of
37、round two are summarized in Tables 7-12 for each transformation temperature parameter (Mf, Mp, Ms, As,Ap, Af). The values are in degrees Celsius. The terms repeatability limit and reproducibility limit are used as specified in PracticeE177.14. Keywords14.1 differential scanning calorimeter; DSC; nic
38、kel-titanium alloy; NiTi; Nitinol; shape memory alloy; TiNi; transformationtemperatureTABLE 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
39、2.9TABLE 3 Precision 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,grandmeanRepeatabilityStandardDeviationReprodu
40、cibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -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
41、 5.6B 2.5 0.67 1.39 1.9 3.9C 91.6 0.80 2.25 2.2 6.3TABLE 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 Samp
42、les are Annealed 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 5.1F2004 174APPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 It is
43、well known that slow cooling after annealing of nickel-rich alloys allows precipitates of the Ni4Ti3 type to form, therebyincreasing the Ti content of the matrix and the transformation temperatures. The practice is to avoid slow cooling and thus preservethe “as annealed” transformation. It is possib
44、le, however, to cool the samples too quickly, raising the transformation temperature,possibly due to stress effects that retain residual martensite. One method of achieving the desired cooling rate is to heat treat thetest specimens on a foil tray and then allow the samples and the foil tray to cool
45、 together, out of the furnace, in room temperatureair.TABLE 8 Precision of Mp, When Samples are Annealed byTesting LaboratoryMaterialMp,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -43.0 1.31 8.69 3.7 24.3B -21.5 1.67 7.31 4.7 20.5C 5
46、8.1 1.31 1.47 3.7 4.1TABLE 9 Precision of Ms, When Samples are Annealed byTesting LaboratoryMaterialMs,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -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 Pre
47、cision of As, When Samples are Annealed byTesting LaboratoryMaterialAs,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -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 Ann
48、ealed byTesting LaboratoryMaterialAp,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -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 9.4TABLE 12 Precision of Af, When Samples are Annealed byTesting LaboratoryMaterialA
49、f,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -16.6 0.87 4.95 2.4 13.9B 6.6 0.69 4.07 1.9 11.4C 94.7 0.91 2.61 2.5 7.3F2004 175X1.2 Differences in sample preparation techniques between laboratories influenced the reproducibility limit. Differences incalibration techniques may have also influenced reproducibility. To minimize interlaboratory variations in results, common samplepreparation and calibration practices must be established.REFERENCE(1) Marquez, J., Slater, T., and Sczerzenie, F., “D
