IEC 61788-25:2018

Overview

IEC 61788-25:2018 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies the test methods and procedures for measuring the tensile mechanical properties of REBCO (Rare-Earth Barium Copper Oxide) superconductive composite tapes at room temperature. REBCO wires are essential components in superconductivity applications due to their high critical temperature and current-carrying capabilities.

This standard outlines precise methods to evaluate key mechanical parameters such as the modulus of elasticity and 0.2% proof strength, which are critical for assessing the reliability and durability of REBCO superconductive tapes used in advanced electrical and electronic systems.

Key Topics

• Scope and Sample Requirements
  The standard applies to REBCO tapes with a rectangular cross-section area ranging from 0.12 mm² to 6.0 mm². This corresponds to tape widths from 2.0 mm to 12.0 mm and thicknesses between 0.06 mm and 0.5 mm.

• Tensile Testing Procedure
  The document specifies detailed procedures for room temperature tensile tests, including specimen preparation, gripping methods, extensometer setup, and testing speeds. Stress-strain data is recorded to determine mechanical properties.

• Measured Properties

  • Modulus of Elasticity (E): Indicates tape stiffness.
  • 0.2% Proof Strength (Rp0.2): Represents the stress at which permanent deformation begins.
  • Elastic Limit, Fracture Strength, and Elongation After Fracture: Included as reference values to provide additional insights on mechanical behavior.

• Uncertainty and Test Reporting
  The standard discusses measurement uncertainty and provides guidelines for accurate reporting of test results, ensuring data consistency and traceability.

• Apparatus Requirements
  Detailed specifications for testing machines and extensometers are included to guarantee reproducible and reliable measurements.

Applications

• Superconducting Wire Manufacturing
  Ensures consistent quality and mechanical performance of REBCO superconductive tapes used in manufacturing superconducting wires and cables.

• Research and Development
  Facilitates standardized testing for academic and industrial research, enabling the development of stronger, more reliable superconducting materials.

• Electrical Engineering Projects
  Supports design and verification of superconducting components in power grids, medical imaging systems (MRI), particle accelerators, and magnetic confinement fusion devices.

• Quality Control and Certification
  Assists manufacturers and certifying bodies in verifying mechanical properties for compliance with international standards and product reliability requirements.

Related Standards

• IEC 61788 Series
  IEC 61788-25 is part 25 of the broader IEC 61788 series on superconductivity, which covers various aspects of superconducting materials and measurement techniques.

• ISO/IEC Directives Part 2
  The drafting and publication of this standard follow the ISO/IEC Directives, ensuring global harmonization and systematic standard development.

• Complementary IEC Standards on Superconductivity
  Related parts address electrical, magnetic, and thermal properties of superconductors, forming a comprehensive framework for superconducting technology standardization.

Keywords: IEC 61788-25, REBCO wires, superconductivity, tensile test, mechanical properties, modulus of elasticity, 0.2% proof strength, superconducting tapes, room temperature test, standardization, electrical engineering, material testing, composite tapes, mechanical reliability.