EN 3948:1998

Overview

EN 3948:1998 is a European standard developed by CEN that specifies the technical requirements for a nickel base alloy designated NI-B15701 (NiPd34Au30) used as filler metal in brazing applications within the aerospace industry. This standard focuses specifically on the wire form of this filler metal, ensuring that materials used in critical aerospace assemblies meet stringent quality and performance criteria.

The standard ensures reliability and durability of brazed joints, which is vital for aerospace components subjected to extreme operational environments. EN 3948:1998 aids manufacturers and engineers in selecting appropriate filler metals that conform to regulatory and safety requirements, helping to maintain high standards in aerospace production and maintenance.

Key Topics

• Nickel Base Alloy Composition
  The standard addresses the composition of the filler metal, NI-B15701, which is a nickel-based alloy with significant palladium (Pd) and gold (Au) content-specifically NiPd34Au30. This unique composition offers corrosion resistance and mechanical strength critical for aerospace brazing.

• Filler Metal Form - Wire
  The filler metal covered by the standard is supplied exclusively in wire form, optimized for precision brazing techniques widely used in aerospace manufacturing and repair.

• Quality and Testing Requirements
  EN 3948:1998 outlines the requirements for chemical composition, physical properties, and mechanical performance to ensure consistent quality. These criteria guarantee that the brazing filler wire meets the necessary standards for aerospace safety and functionality.

• Applicability for Aerospace Components
  The standard emphasizes use in aerospace applications, where the filler metal must provide strong joints capable of withstanding extreme temperature variations, pressure, and corrosive environments typically encountered during flight operations.

Applications

EN 3948:1998 filler wire is primarily used for brazing operations in aerospace manufacturing and component repair. Typical applications include:

• Joining high-performance nickel alloy parts in jet engines and turbine components
• Brazing aerospace structural assemblies requiring excellent corrosion resistance and mechanical stability
• Fabrication and repair of fuel system components where leak-free joints are essential
• Aerospace electrical connectors and sensors requiring precise and reliable brazed joints

This filler metal wire ensures superior joint quality, extending the longevity and safety of aerospace systems.

Related Standards

• EN 3866 - Aerospace Series Filler Metals
  Complementary standards covering other nickel-base filler metals in different forms, enhancing the range of options for brazing aerospace components.

• ISO 17672 - Brazing Filler Metals
  International standards detailing general requirements for brazing filler metals, supporting global harmonization of brazing materials used in various industries including aerospace.

• AMS 4770 - Aerospace Nickel-Based Brazing Alloys
  Industry specifications often referenced alongside EN 3948 for qualifying brazing materials in aerospace manufacturing processes.

By following EN 3948:1998, aerospace manufacturers and maintenance organizations ensure the use of high-quality nickel base filler metal wire NI-B15701, bolstering the structural integrity and reliability of brazed aerospace assemblies. This standard is essential for engineers, materials specialists, and quality assurance professionals focused on aerospace brazing processes.