Magnesium Alloy AZ31B vs AZ91D Powder
Magnesium Alloy · grade comparison
Magnesium Alloy AZ31B and AZ91D Powder are both magnesium alloy grades. AZ91D Powder is the stronger of the two: yield strength 245 MPa (35.5 ksi) against 150 MPa (21.8 ksi) for AZ31B, about 63% more; tensile strength follows at 290 MPa (42.1 ksi) vs 255 MPa (37 ksi). In exchange, AZ31B is the more ductile: elongation 21% versus 2.5% for AZ91D Powder, and AZ91D Powder is harder (75 HB vs 49 HB). AZ31B conducts heat better (96 W/m·K vs 51 W/m·K). On the shop floor, AZ31B welds better (very good vs good) and AZ31B sits in a lower cost tier (standard, $$) than AZ91D Powder (high, $$$$).
AZ31BChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
AZ91D PowderChoose it when strength drives the design.
AZ31B vs AZ91D Powder: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all magnesium alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all magnesium alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 45 GPa6.5 Msi · Shear Modulus 17 GPa2.5 Msi · Poisson's Ratio 0.35 · Shear Strength 145 MPa21 ksi
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Latent Heat of Fusion
Min Service Temperature
Same in both: Thermal Expansion (CTE, 20–100 °C) 26 µm/m·K14.4 µin/in·°F · Max Service Temperature (continuous) 120°C248 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -1.55 V · Corrosion Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Machinability 95 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 32 kg CO₂/kg · Embodied Water 500 L/kg59.9 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | AZ31B | AZ91D Powder |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | O | — |
| Relative cost | $$ Standard | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Anodizing Type II | Yes | — |
| Chem Film (Alodine) | Yes | — |
| E-Coating | Yes | — |
| Hard Anodize Type III w/ PTFE | Yes | — |
| Hard Anodizing Type III | Yes | — |
| Painting | Yes | — |
| Powder Coating | Yes | — |
AZ31B vs AZ91D Powder — frequently asked
Is AZ91D Powder stronger than AZ31B?
Yes. AZ91D Powder has a typical yield strength of 245 MPa (35.5 ksi) against 150 MPa (21.8 ksi) for AZ31B — about 63% more. Tensile strength is 290 MPa (42.1 ksi) vs 255 MPa (37 ksi).
Which is cheaper, AZ31B or AZ91D Powder?
AZ31B is the lower-cost material: it sits in the standard tier ($$) while AZ91D Powder is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, AZ31B or AZ91D Powder?
AZ31B. Its weldability rates very good (70/100) against good (60/100) for AZ91D Powder.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AZ31B and AZ91D Powder 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.