Magnesium Alloy AZ91E-T4 vs AZ91E-T6
Magnesium Alloy · AZ91E temper comparison
AZ91E-T4 and AZ91E-T6 are two conditions of the same magnesium alloy grade, AZ91E: T4 (solution heat treated and naturally aged) versus T6 (solution heat treated and artificially aged). The chemistry is identical, so every difference below comes from the condition. AZ91E-T6 is the stronger of the two: yield strength 145 MPa (21 ksi) against 90 MPa (13.1 ksi) for AZ91E-T4, about 61% more. In exchange, AZ91E-T4 is the more ductile: elongation 14% versus 6% for AZ91E-T6, and AZ91E-T6 is harder (70 HB vs 55 HB). AZ91E-T6 runs hotter in service (150°C vs 120°C continuous).
AZ91E-T4Choose it when the part is bent, formed or impact-loaded.
AZ91E-T6Choose it when strength drives the design, or when the part sees heat.
AZ91E-T4 vs AZ91E-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.
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
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 · Tensile Strength (Ultimate) 275 MPa39.9 ksi · Compressive Strength 345 MPa50 ksi · Hardness, Vickers 75 HV
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 1,000 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.
Same in both: Electrical Conductivity 12 % IACS · 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
Same in both: Machinability Rating (AISI 1212 = 100 %) 300% · Weldability 70 / 100 · Formability (cold) 10 / 100 · Castability 88 / 100 · Brazeability / Solderability 20 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 330 MJ/kg141,875 BTU/lb · Embodied Carbon (primary production) 30 kg CO₂/kg · Embodied Water 400 L/kg47.9 gal/lb · Typical Recycled Content 15%
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.
AZ91E-T4 vs AZ91E-T6 — frequently asked
Is AZ91E-T6 stronger than AZ91E-T4?
Yes. AZ91E-T6 has a typical yield strength of 145 MPa (21 ksi) against 90 MPa (13.1 ksi) for AZ91E-T4 — about 61% more. Tensile strength is 275 MPa (39.9 ksi) vs 275 MPa (39.9 ksi).
Which condition does FabDigit quote by default, T4 or T6?
T6 is the default AZ91E condition in the FabDigit quote flow. 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.
When should I choose AZ91E-T4 over AZ91E-T6?
Pick AZ91E-T4 when the part is bent, formed or impact-loaded. Pick AZ91E-T6 when strength drives the design, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AZ91E-T4 and AZ91E-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.