IEC 61788-5:2013

Overview

IEC 61788-5:2013 is an international standard published by the International Electrotechnical Commission (IEC) that specifies a precise test method for measuring the copper to superconductor volume ratio in Cu/Nb-Ti composite superconducting wires. This standard is crucial for the characterization and quality control of these composite superconductors used in advanced electrical and electronic applications. By defining a methodology based on copper dissolution using nitric acid, IEC 61788-5:2013 enables accurate determination of this volume ratio, which is a key parameter for calculating critical current density and ensuring the performance of superconducting wires.

Key Topics

• Scope of Application: The method targets Cu/Nb-Ti composite superconducting wires with cross-sectional areas from 0.1 mm² to 3 mm² and Nb-Ti filament diameters ranging from 2 µm to 200 µm. It applies mainly when the copper to superconductor volume ratio is 0.5 or higher.
• Test Principle: Copper is selectively dissolved using nitric acid, while Nb-Ti filaments and Nb barriers remain intact. The mass difference before and after dissolution determines the volume ratio.
• Apparatus and Chemicals: A precision balance with ±0.1 mg uncertainty, a draft chamber for safe chemical handling, nitric acid solution (50-65% recommended concentration), organic solvents, degreasing agents, ethyl alcohol, and distilled water are essential for the process.
• Measurement Procedure: Includes specimen preparation, insulating cover removal, cleaning, drying, mass measurements, copper dissolution, and repeated measurements to ensure accuracy and uncertainty control.
• Uncertainty Evaluation: New annexes (E and F) in this edition focus on uncertainty considerations and detailed evaluation methods, enhancing reliability of test results.
• Alternate Methods: Annex A offers an alternate copper mass method for volume ratio determination, particularly useful if specific mass or alloy fractions of Nb-Ti are unknown.

Applications

• Quality Control: Ensures consistent copper to superconductor volume ratios in manufacturing processes of Cu/Nb-Ti composite wires, supporting product uniformity and performance standards.
• Research and Development: Provides reliable volume ratio data critical for developing new superconducting materials and optimizing wire designs.
• Acceptance Testing: Enables manufacturers and clients to verify conformity of superconducting wires with agreed specifications before use.
• Critical Current Density Calculation: Fundamental parameter for calculating the critical current density of superconducting wires, influencing overall conductor performance in practical applications such as MRI machines, particle accelerators, and power transmission.

Related Standards

• IEC 60050-815: International Electrotechnical Vocabulary (IEV), providing terminologies related to superconductivity and electrical measurement, referenced for definitions in IEC 61788-5.
• Other Parts of IEC 61788 Series: Cover additional aspects of superconductivity measurement and testing-important for a comprehensive understanding of composite superconducting wire properties.
• Supplementary Standards: Procedures for material testing, chemical handling, and instrumentation accuracy are aligned with IEC and ISO guidelines to ensure methodological consistency and global acceptance.

Keywords: copper to superconductor volume ratio, Cu/Nb-Ti composite superconducting wire, IEC 61788-5, nitric acid dissolution method, superconductivity testing, critical current density, composite wire quality control, Nb-Ti filaments, superconducting wire measurement, international standard.

For engineers, researchers, and manufacturers in the superconductivity domain, IEC 61788-5:2013 delivers a standardized, scientifically validated approach to measure and control copper to superconductor volume ratios, thereby supporting the reliable production and application of Cu/Nb-Ti composite superconducting wires worldwide.