771.0-T71 Cast Aluminum
771.0-T71 aluminum is 771.0 aluminum in the T71 temper. To achieve this temper, the metal is solution heat-treated and stabilized by artificial overaging, but to a smaller degree than in T7 temper. It has the highest strength compared to the other variants of 771.0 aluminum.
The graph bars on the material properties cards below compare 771.0-T71 aluminum to: ANSI/AA cast aluminums (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
Brinell Hardness
120
Elastic (Young's, Tensile) Modulus
70 GPa 10 x 106 psi
Elongation at Break
2.2 %
Fatigue Strength
120 MPa 18 x 103 psi
Poisson's Ratio
0.32
Shear Modulus
26 GPa 3.8 x 106 psi
Tensile Strength: Ultimate (UTS)
370 MPa 54 x 103 psi
Tensile Strength: Yield (Proof)
350 MPa 51 x 103 psi
Thermal Properties
Latent Heat of Fusion
380 J/g
Maximum Temperature: Mechanical
180 °C 350 °F
Melting Completion (Liquidus)
630 °C 1160 °F
Melting Onset (Solidus)
620 °C 1150 °F
Solidification (Pattern Maker's) Shrinkage
1.6 %
Specific Heat Capacity
870 J/kg-K 0.21 BTU/lb-°F
Thermal Conductivity
140 W/m-K 80 BTU/h-ft-°F
Thermal Expansion
24 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
27 % IACS
Electrical Conductivity: Equal Weight (Specific)
82 % IACS
Otherwise Unclassified Properties
Base Metal Price
9.5 % relative
Density
3.0 g/cm3 190 lb/ft3
Embodied Carbon
8.0 kg CO2/kg material
Embodied Energy
150 MJ/kg 64 x 103 BTU/lb
Embodied Water
1130 L/kg 140 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
8.2 MJ/m3
Resilience: Unit (Modulus of Resilience)
900 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
46 points
Strength to Weight: Axial
35 points
Strength to Weight: Bending
39 points
Thermal Diffusivity
54 mm2/s
Thermal Shock Resistance
16 points
Alloy Composition
| Al | 90.5 to 92.5 | |
| Zn | 6.5 to 7.5 | |
| Mg | 0.8 to 1.0 | |
| Ti | 0.1 to 0.2 | |
| Cr | 0.060 to 0.2 | |
| Si | 0 to 0.15 | |
| Fe | 0 to 0.15 | |
| Mn | 0 to 0.1 | |
| Cu | 0 to 0.1 | |
| res. | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ASTM B618: Standard Specification for Aluminum-Alloy Investment Castings
ASTM B26: Standard Specification for Aluminum-Alloy Sand Castings
Handbook of Aluminum vol. 2: Alloy Production and Materials Manufacturing, George Totten and D. Scott MacKenzie (editors), 2003
ASM Specialty Handbook: Aluminum and Aluminum Alloys, J. R. Davis (editor), 1993