7178-T7651 Aluminum
7178-T7651 aluminum is 7178 aluminum in the T7651 temper. To achieve this temper, the metal is solution heat-treated, stress relieved, then stabilized by artificial overaging. The stress relief is accomplished by stretching the metal by an amount that depends on the type of standard wrought product being made (sheet, plate, bar, or forging). The degree of overaging is chosen so as to maximize exfoliation corrosion resistance.
It has the second lowest strength compared to the other variants of 7178 aluminum.
The graph bars on the material properties cards below compare 7178-T7651 aluminum to: 7000-series alloys (top), all aluminum alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
71 GPa 10 x 106 psi
Elongation at Break
7.4 %
Fatigue Strength
200 MPa 28 x 103 psi
Poisson's Ratio
0.32
Shear Modulus
27 GPa 3.9 x 106 psi
Shear Strength
330 MPa 49 x 103 psi
Tensile Strength: Ultimate (UTS)
570 MPa 83 x 103 psi
Tensile Strength: Yield (Proof)
490 MPa 71 x 103 psi
Thermal Properties
Latent Heat of Fusion
370 J/g
Maximum Temperature: Mechanical
180 °C 350 °F
Melting Completion (Liquidus)
630 °C 1170 °F
Melting Onset (Solidus)
480 °C 890 °F
Specific Heat Capacity
860 J/kg-K 0.2 BTU/lb-°F
Thermal Conductivity
130 W/m-K 72 BTU/h-ft-°F
Thermal Expansion
23 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
31 % IACS
Electrical Conductivity: Equal Weight (Specific)
91 % IACS
Otherwise Unclassified Properties
Base Metal Price
10 % relative
Density
3.1 g/cm3 190 lb/ft3
Embodied Carbon
8.2 kg CO2/kg material
Embodied Energy
150 MJ/kg 62 x 103 BTU/lb
Embodied Water
1110 L/kg 130 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
40 MJ/m3
Resilience: Unit (Modulus of Resilience)
1710 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
45 points
Strength to Weight: Axial
51 points
Strength to Weight: Bending
50 points
Thermal Diffusivity
47 mm2/s
Thermal Shock Resistance
25 points
Alloy Composition
| Al | 85.4 to 89.5 | |
| Zn | 6.3 to 7.3 | |
| Mg | 2.4 to 3.1 | |
| Cu | 1.6 to 2.4 | |
| Fe | 0 to 0.5 | |
| Cr | 0.18 to 0.28 | |
| Si | 0 to 0.4 | |
| Mn | 0 to 0.3 | |
| Ti | 0 to 0.2 | |
| res. | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
Handbook of Aluminum vol. 2: Alloy Production and Materials Manufacturing, George Totten and D. Scott MacKenzie (editors), 2003
ASTM B209: Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate
Aluminum Standards and Data, Aluminum Association Inc., 2013
ASM Specialty Handbook: Aluminum and Aluminum Alloys, J. R. Davis (editor), 1993
EN 573-3: Aluminium and aluminium alloys. Chemical composition and form of wrought products. Chemical composition and form of products