【国外标准】 Standard Test Method for Transformation Temperature of Nickel-Titanium Alloys by Thermal Analysis

5.1 Differential scanning calorimetry provides a rapid method for determining the transformation temperature(s) 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 the current standard.5.5 The use of this test method for finished or semi-finished components without annealing (as in 8.2) shall be agreed upon between the purchaser and the supplier.1.1 This test method defines procedures for determining the transformation temperatures of nickel-titanium shape memory alloys, produced in accordance with Specification F2063, by differential scanning calorimetry.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, health, and environmental practices and to determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.