7075 ALUMINUM ALLOY MATERIAL PROPERTIES

Aluminum 7075 (7000 series) is a high-strength, heat-treatable alloy with zinc as the primary alloying element, typically combined with copper and magnesium. It is widely used in airframe structures and other highly stressed parts. Common tempers include T6, T651, T73, T7351, T76, and T7651.

The T6 temper provides the highest strength but the lowest toughness and stress-corrosion resistance and is generally not recommended for cryogenic service. Temper T73 improves stress-corrosion resistance with a reduction in strength, while T76 increases exfoliation resistance (and limited stress-corrosion resistance) with some strength decrease.

Chemical Composition (Wt. %)

Aluminum 7075 Content (% by weight)
Content Wt. % Content Wt. %
Aluminum87.1 – 91.4Ironmax 0.50
Siliconmax 0.40Copper1.2 – 2.0
Manganesemax 0.30Chromium0.18 – 0.28
Magnesium2.1 – 2.9Zinc5.1 – 6.1
Titaniummax 0.20Othersmax 0.15

Temper Designations (Overview)

  • T6: Solution heat-treated and artificially aged.
  • T651: Solution heat-treated, stress-relieved by stretching, then artificially aged.
  • T73: Solution heat-treated and artificially overaged for improved stress-corrosion resistance.
  • T7351: Solution heat-treated, stress-relieved by stretching, then artificially overaged for improved corrosion resistance.
  • T76: Solution heat-treated and artificially overaged for good exfoliation corrosion resistance.
  • T7651: Solution heat-treated, stress-relieved by stretching, then artificially overaged for good exfoliation corrosion resistance.

Characteristics

Aluminum 7075 Characteristics
Characteristic Al 7075-T6, T651 Al 7075-T73, T7351
General resistance to corrosion Rated C (protect at least on laying surfaces)
Stress-corrosion cracking Rated C (service failures recorded in short-transverse direction; limited lab failures) Rated B (no known service failures; limited lab failures)
Workability (cold) Rated D (A–D scale)
Machinability Rated B (A–E scale)
Brazeability; Gas/Arc Welding Rated D (no commonly used welding methods)
Resistance Spot & Seam Welding Rated B (weldable with special techniques)

Aluminum 7075 Mechanical Properties:

Material Properties of Aluminum:

Applications and Typical Uses:

  • Aerospace structural components such as fuselage frames, bulkheads, and wing fittings
  • High-performance automotive parts
  • Sporting equipment (bicycle frames, climbing gear)
  • Aircraft fittings, missile parts, and other high-strength applications
  • Marine structures where high strength-to-weight ratio is critical

Reference:

  • MMPDS-01, Metallic Materials Properties Development and Standardization (2003)
  • AA-FMA-17, The Aluminum Association, Forming and Machining Aluminum (1988)
  • AA-38, The Aluminum Association, Structural Design with Aluminum (1987)