328.0 (SC82A, A03280) Cast Aluminum
328.0 aluminum is an aluminum alloy formulated for casting. 328.0 is the Aluminum Association (AA) designation for this material. A03280 is the UNS number. Additionally, the SAE designation is 327. Older literature may refer to this material as ASTM SC82A or Red X-8.
The properties of 328.0 aluminum include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare 328.0 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
60 to 82
Elastic (Young's, Tensile) Modulus
72 GPa 10 x 106 psi
Elongation at Break
1.6 to 2.1 %
Fatigue Strength
55 to 80 MPa 8.0 to 12 x 103 psi
Poisson's Ratio
0.33
Shear Modulus
27 GPa 3.9 x 106 psi
Tensile Strength: Ultimate (UTS)
200 to 270 MPa 29 to 40 x 103 psi
Tensile Strength: Yield (Proof)
120 to 170 MPa 17 to 25 x 103 psi
Thermal Properties
Latent Heat of Fusion
510 J/g
Maximum Temperature: Mechanical
180 °C 350 °F
Melting Completion (Liquidus)
620 °C 1140 °F
Melting Onset (Solidus)
560 °C 1050 °F
Solidification (Pattern Maker's) Shrinkage
1.3 %
Specific Heat Capacity
890 J/kg-K 0.21 BTU/lb-°F
Thermal Conductivity
120 W/m-K 70 BTU/h-ft-°F
Thermal Expansion
22 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
30 % IACS
Electrical Conductivity: Equal Weight (Specific)
99 % IACS
Otherwise Unclassified Properties
Base Metal Price
10 % relative
Density
2.7 g/cm3 170 lb/ft3
Embodied Carbon
7.8 kg CO2/kg material
Embodied Energy
140 MJ/kg 62 x 103 BTU/lb
Embodied Water
1070 L/kg 130 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
2.8 to 5.0 MJ/m3
Resilience: Unit (Modulus of Resilience)
92 to 200 kJ/m3
Stiffness to Weight: Axial
15 points
Stiffness to Weight: Bending
51 points
Strength to Weight: Axial
21 to 28 points
Strength to Weight: Bending
28 to 34 points
Thermal Diffusivity
50 mm2/s
Thermal Shock Resistance
9.2 to 12 points
Alloy Composition
Among cast aluminum alloys, the composition of 328.0 aluminum is notable for including chromium (Cr). 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 | 84.5 to 91.1 | |
| Si | 7.5 to 8.5 | |
| Cu | 1.0 to 2.0 | |
| Zn | 0 to 1.5 | |
| Fe | 0 to 1.0 | |
| Mn | 0.2 to 0.6 | |
| Mg | 0.2 to 0.6 | |
| Cr | 0 to 0.35 | |
| Ni | 0 to 0.25 | |
| Ti | 0 to 0.25 | |
| res. | 0 to 0.5 |
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
Iron in Aluminium Alloys: Impurity and Alloying Element, N. A. Belov et al., 2002
Handbook of Aluminum Bonding Technology and Data, J. D. Minford, 1993