FabDigit

7A77 vs AlSi12 and 2 more: properties

7A77AlSi12AlSi10MgAlSi7Mg

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

70 GPa10.2 Msi
72 GPa10.4 Msi
70 GPa10.2 Msi
71 GPa10.3 Msi

Shear Modulus

26.5 GPa3.8 Msi
27 GPa3.9 Msi
26.5 GPa3.8 Msi
26.5 GPa3.8 Msi

Bulk Modulus

69 GPa10 Msi
74 GPa10.7 Msi
69 GPa10 Msi
69 GPa10 Msi

Tensile Strength (Ultimate)

400 MPa58 ksi
400 MPa58 ksi
460 MPa66.7 ksi
350 MPa50.8 ksi

Yield Strength (0.2% offset)

310 MPa45 ksi
250 MPa36.3 ksi
265 MPa38.4 ksi
240 MPa34.8 ksi

Elongation at Break

5%
5%
7%
8%

Compressive Strength

320 MPa46.4 ksi
420 MPa60.9 ksi
480 MPa69.6 ksi
250 MPa36.3 ksi

Shear Strength

245 MPa35.5 ksi
240 MPa34.8 ksi
280 MPa40.6 ksi
215 MPa31.2 ksi

Fatigue Strength (Endurance Limit)

110 MPa16 ksi
100 MPa14.5 ksi
90 MPa13.1 ksi
100 MPa14.5 ksi

Fracture Toughness (K_IC)

20 MPa·√m18.2 ksi·√in
17 MPa·√m15.5 ksi·√in
22 MPa·√m20 ksi·√in
20 MPa·√m18.2 ksi·√in

Charpy V-Notch Impact (RT)

6 J4.4 ft·lbf
4 J3 ft·lbf
4 J2.6 ft·lbf
6 J4.4 ft·lbf

Hardness, Brinell

110 HB
105 HB
119 HB
105 HB

Hardness, Vickers

115 HV
115 HV
125 HV
115 HV

Hardness, Rockwell B

66 HRB

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.81 g/cm³0.1 lb/in³
2.67 g/cm³0.1 lb/in³
2.67 g/cm³0.1 lb/in³
2.67 g/cm³0.1 lb/in³

Melting Point (Solidus)

477°C891 °F
574°C1,065 °F
557°C1,035 °F
557°C1,035 °F

Liquidus Temperature

635°C1,175 °F
585°C1,085 °F
596°C1,105 °F
613°C1,135 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

105 W/m·K60.7 BTU/hr·ft·°F
120 W/m·K69.3 BTU/hr·ft·°F
120 W/m·K69.3 BTU/hr·ft·°F
130 W/m·K75.1 BTU/hr·ft·°F

Specific Heat Capacity

960 J/kg·K0.23 BTU/lb·°F
900 J/kg·K0.21 BTU/lb·°F
900 J/kg·K0.21 BTU/lb·°F
963 J/kg·K0.23 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

23.4 µm/m·K13 µin/in·°F
20.4 µm/m·K11.3 µin/in·°F
21 µm/m·K11.7 µin/in·°F
21.5 µm/m·K11.9 µin/in·°F

Latent Heat of Fusion

390 J/g168 BTU/lb
510 J/g219 BTU/lb
425 J/g183 BTU/lb
389 J/g167 BTU/lb

Max Service Temperature (continuous)

100°C212 °F
120°C248 °F
150°C302 °F
120°C248 °F

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

26 % IACS
27 % IACS
24 % IACS
28 % IACS

Electrical Resistivity

6.6×10⁻⁸ Ω·m2.6 µΩ·in
6.4×10⁻⁸ Ω·m2.52 µΩ·in
7.2×10⁻⁸ Ω·m2.83 µΩ·in
6.2×10⁻⁸ Ω·m2.44 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

40 / 100
55 / 100
55 / 100
58 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.83 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

65 / 100
50 / 100
50 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
50%
70%

Weldability

25 / 100
80 / 100
60 / 100
70 / 100

Formability (cold)

20 / 100
15 / 100
10 / 100
20 / 100

Castability

35 / 100
95 / 100
92 / 100
90 / 100

Brazeability / Solderability

15 / 100
35 / 100
30 / 100
30 / 100

Polishability

60 / 100
55 / 100
55 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

215 MJ/kg92,433 BTU/lb
215 MJ/kg92,433 BTU/lb
240 MJ/kg103,182 BTU/lb
215 MJ/kg92,433 BTU/lb

Embodied Carbon (primary production)

13 kg CO₂/kg
13 kg CO₂/kg
15 kg CO₂/kg
13 kg CO₂/kg

Embodied Water

1,250 L/kg150 gal/lb
1,200 L/kg144 gal/lb
1,200 L/kg144 gal/lb
1,200 L/kg144 gal/lb

Typical Recycled Content

5%
10%
5%
10%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

142 kN·m/kg
150 kN·m/kg
172 kN·m/kg
131 kN·m/kg

Specific Stiffness (E / density)

24.9 MN·m/kg
27 MN·m/kg
26.2 MN·m/kg
26.6 MN·m/kg

Modulus of Resilience

686 kJ/m³
434 kJ/m³
502 kJ/m³
406 kJ/m³

Thermal Diffusivity

38.9 mm²/s
49.9 mm²/s
49.9 mm²/s
50.6 mm²/s

Thermal Shock Resistance Index

26
33
38
30

Strength versus weight

Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scaleAlSi12AlSi10MgAlSi7Mg7A77

Manufacturing and finishing

Capability7A77AlSi12AlSi10MgAlSi7Mg
Default conditionAs PrintedAs PrintedAs PrintedAs Printed
Relative cost$$$$$ Specialty$$$ Premium$$$ Premium$$$ Premium
Min. machined wall
Best machined surface

Both are offered for 3D printing. Both take the same 6 finishes: Anodized (Aluminum AM), Electroless Nickel (EN), Epoxy Coating, Gold Plating, Plated (Metal AM), Silver Plating.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 7A77 and AlSi12 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.