Standard Test Method for Transformation Temperature of Nickel-Titanium Alloys by Thermal Analysis

Importancia y uso:

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

5.2 This test method uses small, stress-free, annealed samples to determine whether a sample of nickel-titanium alloy containing nominally 54.5 to 57.0 % 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.

5.3 This test method 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 by other test methods due to the effects of strain and load on the transformation. For example, transformation temperatures measured in accordance with Test Method F2082 will differ from those measured by this standard.

5.5 The use of this test method for finished or semi-finished components in the aged, shape-set, or tempered conditions shall be agreed upon between the purchaser and the supplier. See Terminology F2005 for the definitions of these heat treat conditions.

Subcomité:

F04.15

Referida por:

F2005-21, F2633-19, E3414-23, F2082_F2082M-23, E3098-24, E3097-23, F2063-18, F2516-22

Volúmen:

13.01

Número ICS:

77.120.40 (Nickel, chromium and their alloys), 77.120.50 (Titanium and titanium alloys)

Palabras clave:

differential scanning calorimeter; DSC; nickel-titanium alloy; NiTi; Nitinol; shape memory alloy; TiNi; transformation temperature;