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Magnesium Alloy AZ91D-HIP vs AZ91D-T4

Magnesium Alloy · AZ91D temper comparison

AZ91D-HIP and AZ91D-T4 are two conditions of the same magnesium alloy grade, AZ91D: HIP (hot isostatic pressed) versus T4 (solution heat treated and naturally aged). The chemistry is identical, so every difference below comes from the condition. AZ91D-HIP is the stronger of the two: yield strength 150 MPa (21.8 ksi) against 90 MPa (13.1 ksi) for AZ91D-T4, about 67% more. In exchange, AZ91D-T4 is the more ductile: elongation 14% versus 6% for AZ91D-HIP, and AZ91D-HIP is harder (65 HB vs 55 HB). AZ91D-HIP conducts electricity better (12.5 % IACS vs 11 % IACS).

AZ91D-HIPChoose it when strength drives the design.

AZ91D-T4Choose it when the part is bent, formed or impact-loaded.

AZ91D-HIP vs AZ91D-T4: properties

AZ91D-HIPAZ91D-T4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

250 MPa36.3 ksi
275 MPa39.9 ksi

Yield Strength (0.2% offset)

150 MPa21.8 ksi
90 MPa13.1 ksi

Elongation at Break

6%
14%

Compressive Strength

170 MPa24.7 ksi
300 MPa43.5 ksi

Shear Strength

145 MPa21 ksi
122 MPa17.7 ksi

Fatigue Strength (Endurance Limit)

110 MPa16 ksi
70 MPa10.2 ksi

Charpy V-Notch Impact (RT)

4 J3 ft·lbf
6 J4.4 ft·lbf

Hardness, Brinell

65 HB
55 HB

Hardness, Vickers

78 HV
60 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 · Fracture Toughness (K_IC) 16 MPa·√m14.6 ksi·√in

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

75 W/m·K43.3 BTU/hr·ft·°F
72 W/m·K41.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

130°C266 °F
120°C248 °F

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 · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

12.5 % IACS
11 % IACS

Electrical Resistivity

1.38×10⁻⁷ Ω·m5.43 µΩ·in
1.41×10⁻⁷ Ω·m5.55 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

32 / 100
33 / 100

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

97 / 100
95 / 100

Machinability Rating (AISI 1212 = 100 %)

390%
300%

Weldability

55 / 100
60 / 100

Formability (cold)

22 / 100
30 / 100

Castability

92 / 100
95 / 100

Polishability

55 / 100
60 / 100

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.

701001502001.41.51.61.71.8Density (g/cm³)Yield strength (MPa) — log scaleAZ91D

AZ91D-HIP vs AZ91D-T4 — frequently asked

Is AZ91D-HIP stronger than AZ91D-T4?

Yes. AZ91D-HIP has a typical yield strength of 150 MPa (21.8 ksi) against 90 MPa (13.1 ksi) for AZ91D-T4 — about 67% more. Tensile strength is 250 MPa (36.3 ksi) vs 275 MPa (39.9 ksi).

Which condition does FabDigit quote by default, HIP or T4?

As Cast is the default AZ91D condition in the FabDigit quote flow (neither HIP 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-HIP or AZ91D-T4?

AZ91D-T4. Its weldability rates good (60/100) against good (55/100) for AZ91D-HIP.

Ready to make it?

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