SIST EN 4449:2005

Overview

SIST EN 4449:2005 is a European standard developed by the European Committee for Standardization (CEN) that specifies the requirements for aluminium alloy AL-P7050 in the T76 temper condition, particularly in sheet form with thicknesses ranging from 0.8 mm to 6 mm. This standard forms part of the aerospace series of specifications aimed at ensuring the consistent quality and performance of metallic materials used in aerospace applications. It applies primarily to rolled aluminium sheets used in structural aerospace components where strength, durability, and corrosion resistance are critical.

This standard was prepared under the European Association of Aerospace Manufacturers (AECMA-STAN) and aligns with other aerospace metallic material standards such as EN 4258 and EN 4400-2, providing a uniform framework for materials used across European aerospace industries.

Key Topics

• Material Specification: Defines the chemical composition limits of aluminium alloy AL-P7050 with detailed element percentages including Silicon, Iron, Copper, Magnesium, Zinc, and others to guarantee optimal mechanical properties.
• Mechanical Properties:
  • Proof stress ranging from 460 MPa to 480 MPa depending on sheet thickness.
  • Tensile strength between 500 MPa to 530 MPa.
  • Minimum elongation of 7% to ensure ductility.
• Forms and Dimensions:
  • Sheets produced by rolling with thicknesses between 0.8 mm and 6 mm.
  • Thickness categories include 0.8 ≤ a < 1.6 mm, 1.6 ≤ a < 3.2 mm, and 3.2 ≤ a ≤ 6 mm.
• Heat Treatment:
  • Delivered in T76 condition involving solution heat treatment, quenching, and artificial ageing to balance strength and stress corrosion resistance.
• Testing and Inspection:
  • Compliance with dimensional, chemical, and physical properties are verified according to defined test methods.
  • Non-destructive tests and corrosion resistance evaluations, including exfoliation corrosion limits.
• Electrical Conductivity:
  • Specified to be within 22.0 to 24.5 MS/m ensuring material reliability in aerospace electrical applications.
• Compliance and Quality Assurance:
  • Mandates product qualification processes agreed upon by manufacturer and purchaser.
  • Marking, batch uniformity, and documentation form part of strict quality control.

Applications

SIST EN 4449:2005 aluminium alloy AL-P7050 - T76 sheets are engineered for critical aerospace structural components where high strength-to-weight ratio and corrosion resistance are essential. Typical applications include:

• Aircraft fuselage panels and frames
• Wing skins and structural supports
• Aerospace-grade precision sheet metal parts
• Helicopter airframe components
• Spacecraft internal structures requiring lightweight and robust materials

This aluminium alloy variant is favored for its excellent combination of mechanical strength, good fracture toughness, and resistance to exfoliation corrosion, making it ideal for long-life aerospace applications under harsh operational environments.

Related Standards

• EN 4258 – General organization and links between aerospace metallic material standards.
• EN 4400-2 – Technical specifications for aluminium alloy wrought products in sheet and strip form.
• EN 4500-2 – Rules for drafting and presenting aerospace metallic material standards, with specific provisions for aluminium and magnesium alloys.
• AECMA-STAN – Aerospace manufacturers’ standards providing a framework for materials selection and standardization across Europe.

Compliance with SIST EN 4449:2005 ensures compatibility with the broader set of aerospace standards necessary for design, certification, and manufacturing in the aviation industry.

Keywords: SIST EN 4449:2005, aluminium alloy AL-P7050, aerospace aluminium sheet, T76 temper, rolled aluminium sheet, aerospace materials standard, aluminium sheet 0.8 mm to 6 mm, aerospace structural aluminium, aerospace alloy specification, aluminium sheet corrosion resistance.