712.0 (ZG61A, A07120) Cast Aluminum
712.0 aluminum is an aluminum alloy formulated for casting. 712.0 is the Aluminum Association (AA) designation for this material. A07120 is the UNS number. Additionally, the SAE designation is 310. And the British Standard (BS) designation is LM31. Older literature may refer to this material as ASTM ZG61A or D712.0.
The properties of 712.0 aluminum include three common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare 712.0 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
75 to 90
Elastic (Young's, Tensile) Modulus
70 GPa 10 x 106 psi
Elongation at Break
4.5 to 4.7 %
Fatigue Strength
140 to 180 MPa 20 to 26 x 103 psi
Poisson's Ratio
0.32
Shear Modulus
27 GPa 3.8 x 106 psi
Shear Strength
180 MPa 26 x 103 psi
Tensile Strength: Ultimate (UTS)
250 to 260 MPa 36 to 38 x 103 psi
Tensile Strength: Yield (Proof)
180 to 200 MPa 27 to 28 x 103 psi
Thermal Properties
Latent Heat of Fusion
380 J/g
Maximum Temperature: Mechanical
190 °C 370 °F
Melting Completion (Liquidus)
640 °C 1180 °F
Melting Onset (Solidus)
610 °C 1120 °F
Solidification (Pattern Maker's) Shrinkage
1.6 %
Specific Heat Capacity
870 J/kg-K 0.21 BTU/lb-°F
Thermal Conductivity
160 W/m-K 92 BTU/h-ft-°F
Thermal Expansion
24 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
40 % IACS
Electrical Conductivity: Equal Weight (Specific)
120 % IACS
Otherwise Unclassified Properties
Base Metal Price
9.5 % relative
Density
3.0 g/cm3 180 lb/ft3
Embodied Carbon
8.0 kg CO2/kg material
Embodied Energy
150 MJ/kg 64 x 103 BTU/lb
Embodied Water
1140 L/kg 140 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
11 MJ/m3
Resilience: Unit (Modulus of Resilience)
240 to 270 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
46 points
Strength to Weight: Axial
24 to 25 points
Strength to Weight: Bending
30 to 31 points
Thermal Diffusivity
62 mm2/s
Thermal Shock Resistance
11 points
Alloy Composition
Among cast aluminum alloys, the composition of 712.0 aluminum is notable for containing a comparatively high amount of zinc (Zn) and including chromium (Cr). Zinc is used to achieve significant increases in strength, at the cost of increased susceptibility to stress corrosion cracking. Among other things, this limits weldability. Chromium is used to limit grain growth during hot working or heat treatment, which improves ductility and toughness. Chromium also reduces the alloy's susceptibility to stress corrosion cracking. If the alloy is anodized, the presence of chromium will tend to add a yellow tint to the film.
| Al | 90.7 to 94 | |
| Zn | 5.0 to 6.5 | |
| Mg | 0.5 to 0.65 | |
| Cr | 0.4 to 0.6 | |
| Fe | 0 to 0.5 | |
| Ti | 0.15 to 0.25 | |
| Si | 0 to 0.3 | |
| Cu | 0 to 0.25 | |
| Mn | 0 to 0.1 | |
| res. | 0 to 0.2 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B618: Standard Specification for Aluminum-Alloy Investment Castings
ASTM B26: Standard Specification for Aluminum-Alloy Sand Castings
Aluminum: Properties and Physical Metallurgy, John E. Hatch (editor), 1984
ASM Specialty Handbook: Aluminum and Aluminum Alloys, J. R. Davis (editor), 1993