Aluminum 7075 Alloy (UNS A97075)

Topics Covered

Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
     Machinability
     Forming
     Welding
     Heat Treatment
     Forging
     Hot Working
     Cold Working
     Annealing
     Aging
     Hardening
Applications

Introduction

Aluminum alloys have strong corrosion resistance. At subzero temperatures, their strength increases, thus making them a useful low-temperature alloy. Their strength decreases if they are subjected to very high temperatures. The aluminum 7075 alloy has high strength.

The following datasheet gives more details about the aluminum 7075 alloy.

Chemical Composition

The following table shows the chemical composition of the aluminum 7075 alloy.

Element Content (%)
Aluminum, Al 90
Zinc, Zn 5.6
Magnesium, Mg 2.5
Copper, Cu 1.6
Chromium, Cr 0.23

Physical Properties

The physical properties of aluminum 7075 alloy are tabulated below.

Properties Metric Imperial
Density 2.8 g/cm3 0.101 lb/in3
Melting point 483°C 900°F

Mechanical Properties

The mechanical properties of aluminum 7075 alloy are outlined in the following table.

Properties Metric Imperial
Tensile strength 220 MPa 31909 psi
Yield strength 95 MPa 13779 psi
Shear strength 150 MPa 21756 psi
Fatigue strength 160 MPa 23206 psi
Elastic modulus 70-80 GPa 10153-11603 ksi
Poisson's ratio 0.33 0.33
Elongation at break 17% 17%
Hardness 60 60

Thermal Properties

The thermal properties of aluminum 7075 alloy are given in the following table.

Properties Conditions
T (ºC) Treatment
Thermal expansion 23.2 (10-6/ºC) 20-100 -
Thermal conductivity 130 W/mK 25 T6

Other Designations

Other designations that are equivalent to aluminum 7075 alloy include:

AMS 4044 ASTM B209 ASTM B468 QQ A-200/15
AMS 4045 ASTM B210 DMS 2233 QQ A-225/9
AMS 4049 ASTM B211 MIL A-12545 QQ A-250/13
AMS 4131 ASTM B221 MIL A-22771 QQ A-250/24
AMS 4147 ASTM B241 MIL F-18280 QQ A-367
AMS 4154 ASTM B247 MIL F-5509 QQ A-430
AMS 4323 ASTM B316 QQ A-200/11 QQ WW-T-700/7
SAE J454

Fabrication and Heat Treatment

Machinability

Aluminum 7075 alloy can be machined in the annealed condition. Oil lubricants are used for performing machining operations.

Forming

Aluminum 7075 alloy can be formed in the annealed condition. It can be warmed at 94 to 122°C (200 to 250°F) if any difficulty is encountered.

Welding

Aluminum 7075 alloy can be welded using resistance welding method. Gas welding method is not preferred for welding this alloy. Arc welding method should also be avoided as it results in degradation of corrosion resistance property of this alloy.

Heat Treatment

Aluminum 7075 alloy is annealed at (900°F) for 2 h followed by water quenching and precipitation hardening heat treatment.

Forging

Aluminum 7075 alloy is forged at 372 to 483°C (700 to 900°F).

Hot Working

Aluminum 7075 alloy can be hot worked at 122°C (250°F)

Cold Working

Aluminum 7075 alloy can be cold worked using conventional methods in soft and annealed condition.

Annealing

Aluminum 7075 alloy is annealed at 413°C (775°F) for 3 h followed by controlled cooling at 10 to 260° C (50 to 500°F) per hour, and cooling in air.

Aging

Aluminum 7075 alloy can be aged at 122°C (250°F) for 24 h to obtain the T 6 temper. The T 73 temper can be heated at 108°C (225°F) for 8 h and at 163°C (325°F) for 24 h followed by air cooling.

Hardening

Aluminum 7075 alloy can be hardened by precipitation heat treatment.

Applications

Aluminum 7075 alloy is mainly used in manufacturing aircraft and other aerospace applications.

Date Added: Aug 31, 2012 | Updated: Jun 11, 2013
Comments
  1. Shajin S Shajin S India says:

    What are the applications of Aluminium 7075 composite with respect to Thermal properties?

    • Alessandro Pirolini Alessandro Pirolini AZoNetwork Team Member says:

      Hi Shajin,

      Thank you for your question. In terms of a metal-matrix composite, an Aluminium 7075 alloy as the matrix and silicon carbide as the reinforcement, is considered to be an excellent structural material used in both the aeronautic/aerospace industry and also the automotive industry. This is due to its high strength-to-weight ratio and its high thermal conductivity.

      I hope this helps to answer your question. Let us know if you require any further information.

      Alessandro

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