384.0 (384.0-F, SC114A, A03840) Cast Aluminum
384.0 aluminum is an aluminum alloy formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. 384.0 is the Aluminum Association (AA) designation for this material. A03840 is the UNS number. Additionally, the SAE designation is 303. The British Standard (BS) designation is LM2. And the AFNOR (French) designation is A-S9U3-Y4. Older literature may refer to this material as ASTM SC114A, but this is now discouraged.
The graph bars on the material properties cards below compare 384.0 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
85
Elastic (Young's, Tensile) Modulus
74 GPa 11 x 106 psi
Elongation at Break
2.5 %
Fatigue Strength
140 MPa 20 x 103 psi
Poisson's Ratio
0.33
Shear Modulus
28 GPa 4.1 x 106 psi
Shear Strength
200 MPa 29 x 103 psi
Tensile Strength: Ultimate (UTS)
330 MPa 48 x 103 psi
Tensile Strength: Yield (Proof)
170 MPa 25 x 103 psi
Thermal Properties
Latent Heat of Fusion
550 J/g
Maximum Temperature: Mechanical
170 °C 340 °F
Melting Completion (Liquidus)
580 °C 1080 °F
Melting Onset (Solidus)
530 °C 980 °F
Specific Heat Capacity
870 J/kg-K 0.21 BTU/lb-°F
Thermal Conductivity
96 W/m-K 56 BTU/h-ft-°F
Thermal Expansion
21 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
22 % IACS
Electrical Conductivity: Equal Weight (Specific)
69 % IACS
Otherwise Unclassified Properties
Base Metal Price
11 % relative
Density
2.9 g/cm3 180 lb/ft3
Embodied Carbon
7.4 kg CO2/kg material
Embodied Energy
140 MJ/kg 59 x 103 BTU/lb
Embodied Water
1010 L/kg 120 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
6.9 MJ/m3
Resilience: Unit (Modulus of Resilience)
190 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
49 points
Strength to Weight: Axial
32 points
Strength to Weight: Bending
37 points
Thermal Diffusivity
39 mm2/s
Thermal Shock Resistance
15 points
Alloy Composition
Among cast aluminum alloys, the composition of 384.0 aluminum is notable for containing comparatively high amounts of silicon (Si) and zinc (Zn). Silicon is used to improve casting fluidity and lower melting temperature. It also has a strengthening effect. 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.
| Al | 77.3 to 86.5 | |
| Si | 10.5 to 12 | |
| Cu | 3.0 to 4.5 | |
| Zn | 0 to 3.0 | |
| Fe | 0 to 1.3 | |
| Mn | 0 to 0.5 | |
| Ni | 0 to 0.5 | |
| Sn | 0 to 0.35 | |
| Mg | 0 to 0.1 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B85: Standard Specification for Aluminum-Alloy Die Castings
Iron in Aluminium Alloys: Impurity and Alloying Element, N. A. Belov et al., 2002
ASM Specialty Handbook: Aluminum and Aluminum Alloys, J. R. Davis (editor), 1993