FabDigitFabDigit

Magnesium Alloy AS41 vs AZ91D

Magnesium Alloy · grade comparison

Magnesium Alloy AS41 and AZ91D are both magnesium alloy grades. AZ91D is the stronger of the two: yield strength 160 MPa (23.2 ksi) against 140 MPa (20.3 ksi) for AS41, about 14% more. In exchange, AS41 is the more ductile: elongation 6% versus 3% for AZ91D, and AZ91D is harder (75 HV vs 63 HV). AS41 runs hotter in service (150°C vs 120°C continuous) and AS41 conducts electricity better (14 % IACS vs 12.2 % IACS). On the shop floor, AZ91D welds better (fair vs poor).

AS41Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

AZ91DChoose it when strength drives the design, or when it will be welded.

AS41 vs AZ91D: properties

AS41AZ91D

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

240 MPa34.8 ksi
230 MPa33.4 ksi

Yield Strength (0.2% offset)

140 MPa20.3 ksi
160 MPa23.2 ksi

Elongation at Break

6%
3%

Compressive Strength

140 MPa20.3 ksi
165 MPa23.9 ksi

Fatigue Strength (Endurance Limit)

110 MPa16 ksi
97 MPa14.1 ksi

Fracture Toughness (K_IC)

14 MPa·√m12.7 ksi·√in
13 MPa·√m11.8 ksi·√in

Charpy V-Notch Impact (RT)

4 J3 ft·lbf
2 J1.6 ft·lbf

Hardness, Brinell

60 HB
63 HB

Hardness, Vickers

63 HV
75 HV

Same in both: Elastic (Young's) Modulus 45 GPa6.5 Msi · Shear Modulus 17 GPa2.5 Msi · Bulk Modulus 45 GPa6.5 Msi · Poisson's Ratio 0.35 · Shear Strength 140 MPa20.3 ksi

Physical

Density and transition temperatures.

Density

1.77 g/cm³0.06 lb/in³
1.81 g/cm³0.07 lb/in³

Melting Point (Solidus)

565°C1,049 °F
470°C878 °F

Liquidus Temperature

620°C1,148 °F
595°C1,103 °F

Thermal

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

Thermal Conductivity

68 W/m·K39.3 BTU/hr·ft·°F
72 W/m·K41.6 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

26.1 µm/m·K14.5 µin/in·°F
26 µm/m·K14.4 µin/in·°F

Latent Heat of Fusion

340 J/g146 BTU/lb
373 J/g160 BTU/lb

Max Service Temperature (continuous)

150°C302 °F
120°C248 °F

Min Service Temperature

-50°C-58 °F
-60°C-76 °F

Same in both: Specific Heat Capacity 1,020 J/kg·K0.24 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

14 % IACS
12.2 % IACS

Electrical Resistivity

1.22×10⁻⁷ Ω·m4.8 µΩ·in
1.41×10⁻⁷ Ω·m5.55 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -1.55 V · Corrosion Resistance 30 / 100

Manufacturability

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

Machinability

95 / 100
98 / 100

Weldability

30 / 100
40 / 100

Formability (cold)

10 / 100
15 / 100

Castability

80 / 100
92 / 100

Brazeability / Solderability

15 / 100
20 / 100

Polishability

50 / 100
55 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 400%

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

30 kg CO₂/kg
32 kg CO₂/kg

Same in both: Embodied Energy (primary production) 320 MJ/kg137,575 BTU/lb · Embodied Water 500 L/kg59.9 gal/lb · Typical Recycled Content 35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

136 kN·m/kg
127 kN·m/kg

Specific Stiffness (E / density)

25.4 MN·m/kg
24.9 MN·m/kg

Modulus of Resilience

218 kJ/m³
284 kJ/m³

Thermal Diffusivity

37.7 mm²/s
39 mm²/s

Same in both: Thermal Shock Resistance Index 14

Strength versus weight

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

701001502001.41.51.61.71.8Density (g/cm³)Yield strength (MPa) — log scaleAZ91DAS41

Manufacturing and finishing

CapabilityAS41AZ91D
CNC machining—Yes
Casting & forging—Yes
Default condition—As Cast
Relative cost$$ Standard$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 0.8 µm
Anodizing Type II—Yes
Chem Film (Alodine)—Yes
E-Coating—Yes
Hard Anodize Type III w/ PTFE—Yes
Hard Anodizing Type III—Yes
Painting—Yes
Powder Coating—Yes

AS41 vs AZ91D — frequently asked

Is AZ91D stronger than AS41?

Yes. AZ91D has a typical yield strength of 160 MPa (23.2 ksi) against 140 MPa (20.3 ksi) for AS41 — about 14% more. Tensile strength is 230 MPa (33.4 ksi) vs 240 MPa (34.8 ksi).

Which is cheaper, AS41 or AZ91D?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which welds better, AS41 or AZ91D?

AZ91D. Its weldability rates fair (40/100) against poor (30/100) for AS41.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AS41 and AZ91D 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.