ASTM F2004-00

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: F 2004 – 00
Standard Test Method for
Transformation Temperature of Nickel-Titanium Alloys by
Thermal Analysis
This standard is issued under the fixed designation F 2004; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 5. Significance and Use
1.1 This test method defines procedures for determining the 5.1 Differential scanning calorimetry provides a rapid
transformation temperatures of nickel-titanium shape memory method for determining the transformation temperature(s) of
alloys. nickel-titanium shape memory alloys.
1.2 The values stated in SI units are to be regarded as the 5.2 This test method uses small, stress-free, annealed
standard. samples to determine whether a sample of nickel-titanium alloy
1.3 This standard does not purport to address all of the containing nominally 54.5 to 56.5 % nickel by weight is
safety concerns, if any, associated with its use. It is the austenitic or martensitic at a particular temperature. Since
responsibility of the user of this standard to establish appro- chemical analysis of these alloys does not have sufficient
priate safety and health practices and to determine the precision to determine the transformation temperature by
applicability of regulatory limitations prior to use. measuring the nickel to titanium ratio of the alloy, direct
measurement of the transformation temperature of an annealed
2. Referenced Documents
sample of known thermal history is recommended.
2.1 ASTM Standards:
5.3 This test method is useful for quality control, specifica-
E 473 Terminology Relating to Thermal Analysis tion acceptance, and research.
E 967 Practice for Temperature Calibration of Differential
5.4 Transformation temperatures derived from differential
Scanning Calorimeters and Differential Thermal Analyz- scanning calorimetry (DSC) may not agree with those obtained
ers
by other test methods due to the effects of strain and load on the
E 1142 Terminology Relating to Thermophysical Proper- transformation.
ties
6. Interferences
F 2005 Terminology for Nickel-Titanium Shape Memory
Alloys 6.1 Make sure the material to be tested is homogeneous
since milligram sample quantities are used.
3. Terminology
6.2 Take care in preparing the sample. Cutting and grinding
3.1 Specific technical terms used in this test method are
can cause cold work, which affects the transformation tempera-
found in Terminologies E 473, E 1142, and F 2005.
ture. Oxidation during heat treatment can change the thermal
conductance of the sample.
4. Summary of Test Method
6.3 Set the gas flow to provide adequate thermal conductiv-
4.1 This test method involves heating and cooling a test
ity in the test cell.
specimen at a controlled rate in a controlled environment
7. Apparatus
through the temperature interval of the phase transformation.
The difference in heat flow between the test material and a 7.1 Use a differential scanning calorimeter capable of heat-
reference material due to energy changes is continuously
ing and cooling at rates up to 10°C/min and of automatically
monitored and recorded. Absorption of energy due to a phase recording the differential energy input between the specimen
transformation in the specimen results in an endothermic peak
and the reference to the required sensitivity and precision.
on heating. Release of energy due to a phase transformation in 7.2 Use sample capsules or pans composed of aluminum or
the specimen results in an exothermic peak on cooling.
other inert material of high thermal conductivity.
7.3 Use nitrogen or helium gas purge supply. See 10.3.1.
7.4 Use an analytical balance with a capacity of 100 mg
This test method is under the jurisdiction of ASTM Committee F04 on Medical
capable of weighing to the nearest 0.1 mg.
and Surgical Materials and Devices and is the direct responsibility of Subcommittee
F04.15 on Material Test Methods.
8. Sampling
Current edition approved Jan. 10, 2000. Published April 2000.
Annual Book of ASTM Standards, Vol 14.02.
8.1 Use a sample size of 20 to 50 mg. Cut the sample to
Annual Book of ASTM Standards, Vol 03.01.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 2004
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