A242.0 (A242.0-T75, A12420) Cast Aluminum
A242.0 aluminum is an aluminum alloy formulated for casting. Cited properties are appropriate for the T75 temper. A242.0 is the Aluminum Association (AA) designation for this material. A12420 is the UNS number.
The graph bars on the material properties cards below compare A242.0 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
Elastic (Young's, Tensile) Modulus
73 GPa 11 x 106 psi
Elongation at Break
1.6 %
Poisson's Ratio
0.33
Shear Modulus
27 GPa 4.0 x 106 psi
Tensile Strength: Ultimate (UTS)
220 MPa 32 x 103 psi
Thermal Properties
Latent Heat of Fusion
390 J/g
Maximum Temperature: Mechanical
210 °C 410 °F
Melting Completion (Liquidus)
680 °C 1250 °F
Melting Onset (Solidus)
550 °C 1020 °F
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
23 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
37 % IACS
Electrical Conductivity: Equal Weight (Specific)
110 % IACS
Otherwise Unclassified Properties
Base Metal Price
12 % relative
Density
3.1 g/cm3 190 lb/ft3
Embodied Carbon
8.3 kg CO2/kg material
Embodied Energy
150 MJ/kg 64 x 103 BTU/lb
Embodied Water
1130 L/kg 130 gal/lb
Common Calculations
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
45 points
Strength to Weight: Axial
20 points
Strength to Weight: Bending
26 points
Thermal Diffusivity
52 mm2/s
Thermal Shock Resistance
9.3 points
Alloy Composition
Among cast aluminum alloys, the composition of A242.0 aluminum is notable for containing a comparatively high amount of copper (Cu) and including chromium (Cr). Copper is used to improve strength. This comes at the cost of a decrease in corrosion resistance and 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 | 89.3 to 93.1 | |
Cu | 3.7 to 4.5 | |
Ni | 1.8 to 2.3 | |
Mg | 1.2 to 1.7 | |
Fe | 0 to 0.8 | |
Si | 0 to 0.6 | |
Cr | 0.15 to 0.25 | |
Ti | 0.070 to 0.2 | |
Mn | 0 to 0.1 | |
Zn | 0 to 0.1 | |
res. | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B26: Standard Specification for Aluminum-Alloy Sand Castings
Handbook of Aluminum Bonding Technology and Data, J. D. Minford, 1993
Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993