Magnesium Alloy AZ91D Stress Relieved vs AZ91D-T6
Magnesium Alloy · AZ91D temper comparison
AZ91D Stress Relieved and AZ91D-T6 are two conditions of the same magnesium alloy grade, AZ91D: Stress Relieved versus T6 (solution heat treated and artificially aged). The chemistry is identical, so every difference below comes from the condition. AZ91D-T6 is the stronger of the two: tensile strength 275 MPa (39.9 ksi) against 220 MPa (31.9 ksi) for AZ91D Stress Relieved, about 25% more. AZ91D-T6 is the more ductile: elongation 6% versus 3.5% for AZ91D Stress Relieved, and AZ91D-T6 is harder (70 HB vs 60 HB).
AZ91D-T6Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
AZ91D Stress Relieved vs AZ91D-T6: 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
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 · Charpy V-Notch Impact (RT) 3 J1.8 ft·lbf
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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 72 W/m·K41.6 BTU/hr·ft·°F · 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 · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Same in both: Electrical Resistivity 1.41×10⁻⁷ Ω·m5.55 µΩ·in
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.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Polishability
Same in both: Brazeability / Solderability 20 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 320 MJ/kg137,575 BTU/lb · Embodied Carbon (primary production) 32 kg CO₂/kg · Embodied Water 500 L/kg59.9 gal/lb · Typical Recycled Content 35%
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 Stress Relieved vs AZ91D-T6 — frequently asked
Is AZ91D-T6 stronger than AZ91D Stress Relieved?
Yes. AZ91D-T6 has a typical tensile strength of 275 MPa (39.9 ksi) against 220 MPa (31.9 ksi) for AZ91D Stress Relieved — about 25% more.
Which condition does FabDigit quote by default, Stress Relieved or T6?
As Cast is the default AZ91D condition in the FabDigit quote flow (neither Stress Relieved nor T6). 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 is easier to machine, AZ91D Stress Relieved or AZ91D-T6?
AZ91D Stress Relieved, by a small margin. Both rate excellent for machinability — 98/100 against 92/100 for AZ91D-T6; for welding the order is AZ91D-T6 first (fair, 50/100) then AZ91D Stress Relieved (fair, 42/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in AZ91D Stress Relieved and AZ91D-T6 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.