Magnesium Alloy AZ91D Powder-SR vs AZ91D Powder-T4
Magnesium Alloy · AZ91D Powder temper comparison
AZ91D Powder-SR and AZ91D Powder-T4 are two conditions of the same magnesium alloy grade, AZ91D Powder: SR (stress relieved) versus T4 (solution heat treated and naturally aged). The chemistry is identical, so every difference below comes from the condition. AZ91D Powder-SR is the stronger of the two: yield strength 220 MPa (31.9 ksi) against 105 MPa (15.2 ksi) for AZ91D Powder-T4, about 110% more. In exchange, AZ91D Powder-T4 is the more ductile: elongation 10% versus 3.5% for AZ91D Powder-SR, and AZ91D Powder-SR is harder (70 HB vs 55 HB). AZ91D Powder-SR conducts heat better (53 W/m·K vs 46 W/m·K).
AZ91D Powder-SRChoose it when strength drives the design.
AZ91D Powder-T4Choose it when the part is bent, formed or impact-loaded.
AZ91D Powder-SR vs AZ91D Powder-T4: 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.
AZ91D Powder-SRAZ91D Powder-T4
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
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 · Fatigue Strength (Endurance Limit) 70 MPa10.2 ksi
Physical
Density and transition temperatures.
Same in both: Density 1.81 g/cm³0.07 lb/in³ · Melting Point (Solidus) 470°C878 °F · Liquidus Temperature 595°C1,103 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Same in both: Specific Heat Capacity 1,020 J/kg·K0.24 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 26 µm/m·K14.4 µin/in·°F · Latent Heat of Fusion 373 J/g160 BTU/lb · Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -1.55 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Same in both: Machinability 95 / 100 · Castability 92 / 100 · Brazeability / Solderability 15 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 375 MJ/kg161,221 BTU/lb · Embodied Carbon (primary production) 32 kg CO₂/kg · Embodied Water 500 L/kg59.9 gal/lb · Typical Recycled Content 5%
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.
AZ91D Powder-SR vs AZ91D Powder-T4 — frequently asked
Is AZ91D Powder-SR stronger than AZ91D Powder-T4?
Yes. AZ91D Powder-SR has a typical yield strength of 220 MPa (31.9 ksi) against 105 MPa (15.2 ksi) for AZ91D Powder-T4 — about 110% more. Tensile strength is 275 MPa (39.9 ksi) vs 265 MPa (38.4 ksi).
Which condition does FabDigit quote by default, SR or T4?
AB is the default AZ91D Powder condition in the FabDigit quote flow (neither SR nor T4). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which welds better, AZ91D Powder-SR or AZ91D Powder-T4?
AZ91D Powder-T4. Its weldability rates good (65/100) against good (60/100) for AZ91D Powder-SR.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AZ91D Powder-SR and AZ91D Powder-T4 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.