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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.

Aluminum (Al) 89.3 to 93.1
Copper (Cu) 3.7 to 4.5
Nickel (Ni) 1.8 to 2.3
Magnesium (Mg) 1.2 to 1.7
Iron (Fe) 0 to 0.8
Silicon (Si) 0 to 0.6
Chromium (Cr) 0.15 to 0.25
Titanium (Ti) 0.070 to 0.2
Manganese (Mn) 0 to 0.1
Zinc (Zn) 0 to 0.1
Residuals 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