Significance and Use
This test method provides a rapid, economical method for determination of transformation temperatures.
Measurement of the specimen motion closely parallels many shape memory applications and provides a result that is applicable to the function of the material.
This test method uses wire, tube, or strip samples; thus, it is able to provide an assessment of the product in its semifinished form.
This test method may be used on annealed samples to determine the transformation temperatures and assure the alloy formulation, since chemical analysis is not precise enough to determine adequately the nickel-to-titanium ratio of shape memory alloys.
Transformation temperatures derived from this test method may differ from those derived from other methods as a result of effects of strain and load on the transformation temperature.
The test method is applicable to shape memory alloys with Af temperatures in the range of approximately – 25 to +90°C.
1.1 This test method describes a procedure for determining the martensite-to-austenite transformation temperatures of either fully-annealed or heat-treated nickel titanium alloys by measuring the deformation recovered during the thermal transformation.
1.2 The values in SI units are to be regarded as the standard. The values given in inch-pound units are provided for information only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E220 Test Method for Calibration of Thermocouples By Comparison Techniques
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
F2005 Terminology for Nickel-Titanium Shape Memory Alloys
free recovery; nickel titanium; nitinol; shape memory; transformation temperature;
ICS Number Code 77.120.50 (Titanium and titanium alloys)
ASTM International is a member of CrossRef.
Citing ASTM Standards
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