Aluminium ENAW-AlZn5.5MgCu Bars & Rods (EU EN, DIN, WNR)

Product Description

Here is the technical breakdown for EN AW-AlZn5.5MgCu bar and rod stock. This is a high-strength, aerospace-grade structural alloy primarily driven by its zinc, magnesium, and copper content.

1. International Standard Equivalents

The chemical designation AlZn5.5MgCu belongs to the high-strength 7000 series. It is heavily utilized across defense, aerospace, and highly stressed mechanical components.

• EN/DIN: EN AW-7075 (EN AW-AlZn5.5MgCu)

• WNr (Werkstoffnummer): 3.4365

• ISO: Al-Zn5.5MgCu

• AISI/SAE (US): 7075

• AFNOR (France): A-Z5GU

• JIS (Japan): A7075

2. Chemical Composition

The addition of copper (Cu) combined with zinc (Zn) and magnesium (Mg) creates an alloy capable of extreme age-hardening, approaching the mechanical strength profiles of structural steels.

3. Typical Mechanical Properties (Bar & Rod)

Mechanical values vary heavily depending on the chosen temper and product thickness (cross-section). Below are typical minimum specifications for extruded bars and rods (up to 100mm diameter) under T6 (maximum strength) and T73 (stabilized for stress corrosion resistance) tempers according to EN 755-2.

4. Engineering & Processing Characteristics

• Machinability: This alloy offers excellent machining characteristics. It chips smoothly and produces clean finishes when turned, milled, or drilled, making it ideal for precision CNC components.

• Corrosion & Temper Selection:

  • The T6 temper yields peak static strength but makes the alloy vulnerable to stress corrosion cracking (SCC) in highly stressed environments.

  • The T73 temper uses an overaging heat treatment to drastically improve resistance to SCC and exfoliation corrosion, trading off roughly 10% to 15% of the ultimate tensile strength.

• Anodizing: It can be hard-coat anodized for wear resistance, but the high copper and zinc content means it does not form the flawless decorative clear-anodized finish seen on cleaner alloys like 6063.

• Weldability: Not recommended for conventional welding. Joining via MIG/TIG processes introduces high risks of hot cracking and significant strength degradation in the heat-affected zone. Friction stir welding or mechanical fasteners are favored.

5. Primary Structural Applications

• Aerospace & Defense: Aircraft structural ribs, fuselage stringers, upper wing skins, and military ordnance parts.

• High-Stress Machinery: Highly loaded gears, shafts, valve bodies, and hydraulic manifolds.

• Tooling: Mold blocks for injection molding or blow molding of plastics where rapid thermal transfer and high surface hardness are required.