SIST EN 3927:2002

Overview

SIST EN 3927:2002 is a European standard established by CEN that specifies the requirements for the aerospace-grade nickel base alloy NI-B40001 (NiSi5B3). This material is used as a filler metal for brazing in powder or paste form. Designed specifically for aerospace applications, this standard ensures the critical quality, composition, and performance criteria needed for reliable brazed joints in highly demanding environments.

This standard is part of a comprehensive series of aerospace metal material standards and aligns with EN 4500-6 as well as related normative references. It sets the technical and chemical specifications for this specialized filler metal, supporting manufacturers and engineers in achieving consistent brazing outcomes for corrosion and heat-resistant steel alloys and other aerospace metals.

Key Topics

• Material Composition
  The filler metal NI-B40001 (NiSi5B3) comprises a nickel base alloy with controlled content of silicon (Si) and boron (B), ensuring optimal brazing properties. Chemical composition limits and maximum impurity content are defined to maintain alloy integrity and performance.

• Forms and Production Methods

  • Powder: Produced by water or inert gas atomization and sieving
  • Paste: Powder mixed with a suitable binder
    Both forms are supplied as manufactured without additional heat treatments.

• Physical and Mechanical Characteristics
  Parameters such as liquidus (approx. 1040°C) and solidus temperatures (approx. 980°C), wettability, particle size, and metallic alloy content (minimum 84% for powder and 90% for paste) are specified. Properties like proof stress, tensile strength, elongation, hardness, and shear strength are essential indicators covered in related standards such as EN 3875.

• Quality Control and Testing
  The standard references rigorous testing for external defects, batch uniformity, dimensional accuracy, and heat treatment conditions. These aspects are vital for aerospace quality assurance, especially relating to the material's ability to join corrosion and heat-resistant steels effectively.

• Applicable Normative References
  EN 2043, EN 3875, EN 4258, and EN 4500-6 are integral to the standard, providing guidelines on material qualification, filler metal specifications, standardization organization, and drafting rules.

Applications

• Aerospace Industry
  SIST EN 3927:2002 filler metals are primarily used for brazing high-performance components in aerospace manufacturing and repairs. They offer excellent properties for joining corrosion-resistant and heat-resistant nickel alloys and steels crucial in aircraft engines, structural components, and thermal protection systems.

• Corrosion and Heat Resistant Joining
  The nickel base filler metal ensures strong, reliable joints that can withstand extreme temperatures and corrosive environments common in aerospace equipment and systems.

• Precision Powder and Paste Brazing
  The standard accommodates both powder and paste filler metals, providing versatility for different brazing techniques-from high-precision automated processes to manual application in repair and maintenance.

Related Standards

• EN 2043 – Aerospace series general requirements for metallic semi-finished product qualification (excluding forgings and castings)
• EN 3875 – Technical specification for filler metals for brazing in aerospace applications
• EN 4258 – Standardization structure linking different types of EN aerospace metal standards
• EN 4500-6 – Guidelines for drafting and presentation of aerospace material standards, particularly for filler metals

These associated standards collectively establish a cohesive framework ensuring material consistency, safety, and reliability in aerospace brazing operations using the NI-B40001 nickel base filler metal.

Keywords: SIST EN 3927:2002, nickel base alloy, NI-B40001, NiSi5B3, filler metal, brazing, aerospace brazing standard, powder brazing filler, paste brazing filler, aerospace materials, corrosion resistant brazing, heat resistant brazing, aerospace manufacturing standards, CEN standards, aerospace alloys.