EN 4204:2005

Overview

EN 4204:2005 is a European Standard developed by the European Committee for Standardization (CEN) that specifies requirements for the aerospace-grade aluminium alloy AL-P8090 in the T841 temper condition. This standard applies to rolled sheets with thicknesses ranging from 0.6 mm to 6 mm designed for aerospace applications. The material is part of a series of EN metallic material standards aimed at ensuring high-quality, consistent aerospace components. Compliance with EN 4204:2005 ensures materials meet strict chemical composition, mechanical properties, and manufacturing process standards demanded by the aerospace industry.

Key Topics

• Material Specification: Defines aluminium alloy AL-P8090 in the T841 temper condition. This alloy includes controlled amounts of copper, magnesium, zirconium, and lithium to provide a balance of strength, corrosion resistance, and lightweight properties crucial for aerospace applications.

• Thickness Range: Sheets must have thicknesses between 0.6 mm and 6 mm, meeting precise dimensional tolerances.

• Chemical Composition: Tight limits on elements such as silicon, iron, copper, manganese, magnesium, zinc, lithium, zirconium, titanium, and residuals to ensure consistent performance.

• Mechanical Properties:

  • Proof stress minimum: 270 MPa
  • Tensile strength minimum: 405 MPa
  • Elongation minimum: 8% (on 50 mm gauge length)
    These properties are critical to guarantee material reliability under aerospace operational stresses.

• Delivery Condition:

  • Material supplied in the T841 condition, involving solution heat treatment, water quenching, and controlled stretching followed by artificial aging.
  • This treatment optimizes mechanical strength and stress corrosion resistance.

• Testing & Inspection: Mandates use of standard aerospace test samples and protocols (referencing EN 4400-2) including dimensional inspection, fracture toughness, and corrosion resistance tests.

• Microstructure and Quality: Sheets are to be fully recrystallized per agreement, ensuring uniform grain structure and performance consistency.

• Corrosion Resistance: Requirements limit exfoliation corrosion severity to levels not greater than grade EB, essential for longevity in demanding aerospace environments.

• Marking & Traceability: Products must be properly marked and traceable according to aerospace standards.

Applications

• Aerospace Manufacturing: EN 4204:2005 aluminium sheets are intended for structural aircraft components where a lightweight, high-strength metal with excellent corrosion resistance is required.

• Aircraft Skin and Panels: Suitable for outer aircraft skins, fuselage panels, and other sheet metal parts exposed to environmental and operational stresses.

• Spacecraft Components: The alloy’s properties also make it applicable to certain spacecraft parts requiring stringent mechanical and chemical stability.

• High-Performance Engineering: Used in aerospace design to reduce weight while maintaining rigidity and durability, thereby improving fuel efficiency and safety.

Related Standards

• EN 4400-2: Aerospace series technical specification for aluminium and aluminium alloy wrought products - Part 2 covers sheet and strip products, establishing testing and inspection rules complementary to EN 4204.

• EN 4258: General organization of standardization for aerospace series metallic materials, providing framework and interrelations between different material standards.

• EN 4500-2: Rules for drafting and presenting standards for metallic materials in aerospace, giving guidance specific to aluminium, its alloys, and magnesium alloys.

• AECMA-STAN Documents: Based on pre-standardization efforts by the European Association of Aerospace Manufacturers, ensuring alignment with industry needs.

Keywords: EN 4204:2005, aluminium alloy AL-P8090 T841, aerospace aluminium sheet, rolled aluminium sheet aerospace, aerospace material standard, lightweight aerospace metal, corrosion-resistant aluminium, tensile strength aluminium aerospace, aerospace grade aluminium, aluminium sheet 0.6 mm to 6 mm, aerospace manufacturing materials.