Differential scanning calorimetry provides a rapid method for determining the transformation temperature(s) of nickel-titanium shape memory alloys.

This test method uses small, stress-free, annealed samples to determine whether a sample of nickel-titanium alloy containing nominally 54.5 to 56.5 % nickel by weight is austenitic or martensitic at a particular temperature. Since chemical analysis of these alloys does not have sufficient precision to determine the transformation temperature by measuring the nickel to titanium ratio of the alloy, direct measurement of the transformation temperature of an annealed sample of known thermal history is recommended.

This test method is useful for quality control, specification acceptance, and research.

Transformation temperatures derived from differential scanning calorimetry (DSC) may not agree with those obtained by other test methods due to the effects of strain and load on the transformation.

1. Scope

1.1 This test method defines procedures for determining the transformation temperatures of nickel-titanium shape memory alloys.

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 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 to 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.

ASTM Standards

E473 Terminology Relating to Thermal Analysis and Rheology

E967 Test Method for Temperature Calibration of Differential Scanning Calorimeters and Differential Thermal Analyzers

E1142 Terminology Relating to Thermophysical Properties

F2005 Terminology for Nickel-Titanium Shape Memory Alloys

Keywords

differential scanning calorimeter; DSC; nickel-titanium alloy; NiTi; Nitinol; shape memory alloy; TiNi; transformation temperature; Nickel-titanium surgical implant alloys; Thermal analysis (TA)--metals/alloys; Transformation temperature;

ICS Code

ICS Number Code 77.120.40 (Nickel, chromium and their alloys); 77.120.50 (Titanium and titanium alloys)

Citing ASTM Standards

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