About 7xxx Series Alloys
Zinc is the primary alloying agent for this series, and when magnesium is added in a smaller amount, the result is a heat-treatable, very high strength alloy. Other elements such as copper and chromium may also be added in small quantities. The most commonly known alloys are 7050 and 7075, which are widely used in the aircraft industry.
Characteristics
7075 T6 is a very high strength material used for highly stressed structural parts. The T7351 temper offers improved stress-corrosion cracking resistance.
Applications
Aircraft fittings, gears and shafts, fuse parts, meter shafts and gears, missile parts, regulating valve parts, worm gears, keys, aircraft, aerospace and defense applications; bike frames, all terrain vehicle (ATV) sprockets.
Technical Specifications
The guaranteed minimum mechanical properties of 7075 T6 alloy are tabulated below.
| Physical Properties |
Metric |
| Density |
2.81 g/cc |
| Mechanical Properties |
Metric |
| Hardness, Brinell |
150 |
| Hardness, Vickers |
175 |
| Tensile Strength, Ultimate |
572 MPa |
| Tensile Strength, Yield |
503 MPa |
| Elongation at Break |
11.0% |
| Poissons Ratio |
0.33 |
| Fatigue Strength |
159 MPa |
| Machinability |
70 % |
| Shear Modulus |
26.9 GPa |
| Shear Strength |
331 MPa |
| Electrical Properties |
Metric |
| Electrical Resistivity |
0.00000515 ohm-cm @ 20 °C |
| Thermal Properties |
Metric |
| CTE, linear |
23.6 µm/m-°C |
| Specific Heat Capacity |
0.960 J/g-°C |
| Thermal Conductivity |
130 W/m-K |
| Melting Point |
477 - 635 °C |
| Solidus |
477 °C |
| Liquidus |
635 °C |
| Processing Properties |
Metric |
| Annealing Temperature |
413 °C |
| Solution Temperature |
466 - 482 °C |
| Aging Temperature |
121 °C |
| Component Elements Properties |
Metric |
| Aluminum, Al |
87.1 - 91.4 % |
| Chromium, Cr |
0.18 - 0.28 % |
| Copper, Cu |
1.2 - 2.0 % |
| Iron, Fe |
<= 0.50 % |
| Magnesium, Mg |
2.1 - 2.9 % |
| Manganese, Mn |
<= 0.30 % |
| Other, each |
<= 0.05 % |
| Other, total |
<= 0.15 % |
| Silicon, Si |
<= 0.40 % |
| Titanium, Ti |
<= 0.20 % |
| Zinc, Zn |
5.1 - 6.1 % |