Aluminium UNI P-AlZn5.8MgCuCr Plates - UNS A97075 Sheets

Product Description

The designations UNI P-AlZn5.8MgCuCr and UNS A97075 are respectively the Italian (UNI) and North American (UNS) standards for 7075 Aluminium. These represent the highest strength tier of the 7000-series alloys, often used in aerospace and high-stress mechanical engineering.

1. Key Designations

2. Chemical Composition (Typical %)

The Italian UNI designation explicitly lists the primary alloying elements (Zinc, Magnesium, Copper, and Chromium) which provide its characteristic high strength and fatigue resistance.

• Zinc (Zn): 5.10 “ 6.10% (The primary hardening agent)

• Magnesium (Mg): 2.10 “ 2.90%

• Copper (Cu): 1.20 “ 2.00%

• Chromium (Cr): 0.18 “ 0.28%

• Aluminium (Al): Remainder

3. Mechanical Properties (T6 / T651 Temper)

These properties make 7075 a viable alternative to steel in applications where weight reduction is critical.

4. Application-Specific Forms

• UNS A97075 Sheets: Typically used for aircraft skins, fuselages, and panels. These are often "Alclad" (coated with pure aluminium) to compensate for the alloy's naturally low corrosion resistance.

• UNI P-AlZn5.8MgCuCr Plates & Blocks: Heavier sections used for machined structural parts, gear sets, and plastic injection molds.

5. Fabrication & Usage Notes

• Machinability: Excellent. It is highly responsive to CNC milling and turning, producing clean finishes and stable tolerances.

• Corrosion Resistance: Low. Without surface treatment (like anodizing or chromating), it is susceptible to atmospheric and stress corrosion.

• Joining: Mechanical fasteners (rivets, bolts) are preferred. Arc welding is generally not recommended as it degrades the heat-treated properties and causes crack sensitivity.

Technical Tip: If you are machining large plates, specify the T651 temper. This "stress-relieved" state prevents the plate from warping or "walking" after you remove large amounts of material during the milling process.