ASTM F2082/F2082M-16 rus PDF

Full title and description

ASTM F2082/F2082M-16 — Standard Test Method for Determination of Transformation Temperature of Nickel‑Titanium Shape Memory Alloys by Bend and Free Recovery. This 2016 ASTM test method (often called the BFR method) defines a laboratory procedure to determine the martensite→austenite transformation temperatures (including Af) of Ni‑Ti (Nitinol) wires, tubes and strips by measuring deformation recovered during controlled heating after bending.

Abstract

This standard describes the Bend‑and‑Free‑Recovery (BFR) technique for measuring transformation temperatures of nickel‑titanium shape‑memory alloys. A specimen is bent to a specified outer‑fiber strain, heated while unconstrained, and the recovered deformation versus temperature is recorded; transformation temperatures are derived from the recovery curve. The method is intended primarily for semifinished forms (wire, tube, strip) but is commonly adapted for finished components as a process‑control measurement.

General information

• Status: Superseded — the F2082/F2082M-16 edition has been revised; the most recent revision is ASTM F2082/F2082M-23 (published October 15, 2023).
• Publication date: 1 April 2016 (designated F2082/F2082M‑16).
• Publisher: ASTM International (formerly American Society for Testing and Materials).
• ICS / categories: 77.120.50 (Titanium and titanium alloys); materials testing; shape memory alloys.
• Edition / version: F2082/F2082M‑16 (2016 revision of the F2082 series).
• Number of pages: 7 pages (F2082/F2082M‑16 document).

Scope

The test method provides a procedure to determine martensite‑to‑austenite (and where applicable martensite→R‑phase) transformation temperatures of annealed, heat‑treated, aged or shape‑set nickel‑titanium alloys by measuring recovered deformation during heating after bending. Specimens may be wire, tube or strip or coupons prepared from larger parts (prepared so that test deformation is pure bending). The standard specifies units in both SI and inch‑pound systems (each to be used independently) and is applicable for Af temperatures roughly in the range −25 °C to +90 °C. Safety and regulatory responsibilities are left to the user.

Key topics and requirements

• Test principle: bend specimen to a controlled outer‑fiber strain, then heat freely and record recovered deformation versus temperature (Bend & Free Recovery, BFR).
• Specimen forms permitted: wire, tube, strip, or shaped coupons derived from components (with guidance to achieve pure bending deformation).
• Bending strain: standard provides nominal outer‑fiber strain guidance (commonly ~2.0–2.5%) and specimen preparation details to ensure repeatability.
• Temperature control and measurement: requirements for heating rate, thermal environment, and temperature measurement to derive transformation points (start/finish temperatures such as As, Af).
• Data reduction: methods to convert recovery versus temperature curves into transformation temperatures and reporting conventions.
• Applicability and limitations: results may differ from other techniques (DSC, dilatometry) because strain and load affect apparent transformation temperatures; the method is optimized for semifinished forms.
• Precision and interlaboratory performance: precision statements and interlaboratory study results exist for the method (reference interlaboratory reports associated with the standard).

Typical use and users

Primary users are materials and process engineers, quality control laboratories, and R&D teams in industries that use Nitinol: medical device manufacturers (stents, occluders, guidewires), Nitinol wire/tube/strip suppliers, contract testing laboratories, and research institutions. Regulators and submission authors frequently reference this method when characterizing Af (austenite finish) for device performance and premarket documentation.

Related standards

Commonly referenced and related documents include ASTM F2005 (terminology and definitions for nickel‑titanium shape memory alloys), ASTM F2063 (specification for wrought Ni‑Ti for medical devices), ASTM F2633 (specification for wrought seamless Ni‑Ti tube for medical devices), and associated ASTM interlaboratory reports for F2082. FDA guidance documents on non‑clinical assessment of Nitinol devices also discuss characterization of Af and may reference F2082 methods.

Keywords

ASTM F2082, F2082M, Nitinol, nickel‑titanium, shape memory alloy, transformation temperature, Af, austenite finish, Bend and Free Recovery, BFR, martensite, R‑phase, superelasticity, material characterization, medical device testing.

FAQ

Q: What is this standard?

A: ASTM F2082/F2082M‑16 is a 2016 ASTM test method that defines the Bend‑and‑Free‑Recovery (BFR) procedure to determine transformation temperatures (e.g., Af) of nickel‑titanium shape memory alloys using bent specimens that are heated free to recover.

Q: What does it cover?

A: It covers specimen preparation (wire, tube, strip or coupons), bending to a controlled outer‑fiber strain, controlled heating and temperature measurement, recording recovered deformation versus temperature, and procedures to derive transformation temperature values from the recovery curve. It also states the applicable Af temperature range (~−25 °C to +90 °C) and notes limitations where strain/loading can shift measured temperatures.

Q: Who typically uses it?

A: Suppliers and manufacturers of Nitinol material and devices (especially medical device manufacturers), materials testing laboratories, QA/QC and process engineers, and researchers characterizing Ni‑Ti thermomechanical behavior.

Q: Is it current or superseded?

A: The F2082/F2082M‑16 edition has been revised; the standard was updated and published as ASTM F2082/F2082M‑23 on 15 October 2023. Users should cite and use the 2023 revision for the latest requirements and clarifications; the 2016 text remains useful for historical or legacy comparisons.

Q: Is it part of a series?

A: Yes — F2082 is part of a family of ASTM documents addressing nickel‑titanium materials and testing practices and is frequently used alongside ASTM F2005 (terminology), ASTM F2063 (material specification for wrought Ni‑Ti), and other ASTM specifications and guides for Nitinol products and testing.

Q: What are the key keywords?

A: Nitinol, nickel‑titanium, shape memory alloy, transformation temperature, Af, bend and free recovery (BFR), martensite, austenite, R‑phase, superelastic, ASTM F2082.