1、Designation: F2004 05 (Reapproved 2010)Standard 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
2、 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 defines procedures for determining thetransformation temperatures of nickel-ti
3、tanium shape memoryalloys.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, associated with its use. It is theresponsibility of the user of this
4、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:2E473 Terminology Relating to Thermal Analysis and Rhe-ologyE967 Test Method for Temperature Calibration of Differen-tial
5、Scanning Calorimeters and Differential Thermal Ana-lyzersE1142 Terminology Relating to Thermophysical PropertiesF2005 Terminology for Nickel-Titanium Shape MemoryAlloys3. Terminology3.1 Specific technical terms used in this test method arefound in Terminologies E473, E1142, and F2005.4. Summary of T
6、est Method4.1 This test method involves heating and cooling a testspecimen at a controlled rate in a controlled environmentthrough the temperature interval of the phase transformation.The difference in heat flow between the test material and areference material due to energy changes is continuouslym
7、onitored and recorded. Absorption of energy due to a phasetransformation in the specimen results in an endothermic peakon heating. 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 prov
8、ides a rapidmethod for determining the transformation temperature(s) ofnickel-titanium shape memory alloys.5.2 This test method 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 martensi
9、tic at a particular temperature. Sincechemical analysis of these alloys does not have sufficientprecision to determine the transformation temperature bymeasuring the nickel to titanium ratio of the alloy, directmeasurement of the transformation temperature of an annealedsample of known thermal histo
10、ry is recommended.5.3 This test method is useful for quality control, specifica-tion acceptance, and research.5.4 Transformation temperatures derived from differentialscanning calorimetry (DSC) may not agree with those obtainedby other test methods due to the effects of strain and load on thetransfo
11、rmation.6. Interferences6.1 Make sure the material to be tested is homogeneoussince milligram sample quantities are used.6.2 Take care in preparing the sample. Cutting and grindingcan cause cold work, which affects the transformation tempera-ture. Oxidation during heat treatment can change the therm
12、alconductance 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 energy input between the specimena
13、nd the reference to the required sensitivity and precision.1This test method is under the jurisdiction of ASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved June 1, 2010. Published S
14、eptember 2010. Originallyapproved in 2000. Last previous edition approved in 2005 as F2004 05. DOI:10.1520/F2004-05R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer
15、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.7.2 Use sample capsules or pans composed of aluminum orother inert material of high thermal conductivity.7.3 Use helium gas pur
16、ge supply. See 10.3.1.7.4 Use an analytical balance with a capacity of 100 mgcapable 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 o
17、r inert atmosphere, or in air with adequate protectionfrom oxidation. Rapidly cool the sample to prevent precipita-tion of phases which may change transformation temperatureof the alloy.8.3 Clean the sample of all foreign materials such as cuttingfluid. If the sample is oxidized in heat treatment, g
18、rind, polish,or etch the sample to remove the oxide. Take care to avoid coldworking the sample as this will change its thermal response.Slight oxidation is permissible but remove all heavy oxidescale.9. Calibration9.1 Calibrate the temperature axis of the instrument usingthe same heating rate, purge
19、 gas, and flow rate as those used foranalyzing the specimen in accordance with Practice 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/min.10.3.1
20、 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.10.4.2 Heat t
21、he sample from room temperature to a tem-perature of at least Af+ 30C; hold at temperature for a timesufficient 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, heat the samp
22、le 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 tangents to the cool
23、ing 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 maximuminclinati
24、on 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 Complete iden
25、tification 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 the temperature
26、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.13. Precision and Bia
27、s13.1 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 first round,all the test samples were annealed in one laboratory; i
28、n thesecond round, the samples were annealed by the laboratory thatconducted the test. The details are given in ASTM ResearchReport No. F041008.33Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:F04-1008.FIG. 1 DSC Curve for Nicke
29、l-Titanium (NiTi)TABLE 1 Precision of MfMaterial Mf,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 05 (2010)213.2 The results of round one are summarized in
30、Tables 1-6for each transformation temperature 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 temperatur
31、e 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.TABLE 2 Precision of MpMaterial Mp,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibili
32、tyLimitA -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 Precision of MsMaterial Ms,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 3.2T
33、ABLE 4 Precision of AsMaterial As,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -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 ApMaterial Ap,grandmeanRepeatabilityStandardDeviationReproducib
34、ilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -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 6 Precision of AfMaterial Af,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -23.4 0.23 2.01 0.6 5.
35、6B 2.5 0.67 1.39 1.9 3.9C 91.6 0.80 2.25 2.2 6.3TABLE 7 Precision of Mf, When Samples are Annealed byTesting LaboratoryMaterial Mf,grandmeanRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -49.1 2.03 8.49 5.7 23.8B -27.3 1.85 5.93 5.2 16.6C 48.5 1
36、.23 1.84 3.4 5.1TABLE 8 Precision of Mp, When Samples are Annealed byTesting LaboratoryMaterial Mp,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 Precisio
37、n of Ms, When Samples are Annealed byTesting LaboratoryMaterial Ms,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 Precision of As, When Samples are Annea
38、led byTesting LaboratoryMaterial As,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 Annealed byTesting LaboratoryMaterial
39、Ap,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 LaboratoryMaterial Af,grandmeanRepeatabilityStandardD
40、eviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitA -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 05 (2010)314. Keywords14.1 differential scanning calorimeter; DSC; nickel-titaniumalloy; NiTi; Nitinol; shape memory alloy; TiNi; transformati
41、ontemperatureAPPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 This test method 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
42、 analysis of these alloys does not have sufficientprecision to determine the transformation temperature bymeasuring the nickel to titanium ratio of the alloy, directmeasurement of the transformation temperature of an annealedsample of known thermal history is recommended.X1.2 It is well known that s
43、low cooling after annealing ofnickel-rich alloys allows precipitates of the Ni4Ti3type toform, thereby increasing the Ti content of the matrix and thetransformation temperatures. The practice is to avoid slowcooling preserve the “as annealed” transformation. It is pos-sible, however, to cool the sam
44、ples too quickly, raising thetransformation temperature, possibly due to stress effectswhich retain residual martensite. 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,
45、 in room temperature air.X1.3 Transformation 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.X1.4 Differences in sample preparation techniques betweenlaboratories influe
46、nced the reproducibility limit. Differences incalibration techniques may have also influenced reproducibil-ity. To minimize interlaboratory variations in results, commonsample preparation and calibration practices must beestablished.ASTM International takes no position respecting the validity of any
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