Magnesium Alloy AZ91E-T5
Temper
ASTM AZ91E · UNS M11919
T5 = cooled from hot working and artificially aged
Low-distortion, low-cost aging of as-cast parts giving a modest hardness/yield gain without a solution soak.
Values for the T5 condition
Other AZ91E tempers and conditions
AZ91E is listed in 4 conditions; see the grade overview at AZ91E.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution heat treated and naturally aged | Pick when maximum ductility, toughness and impact resistance matter more than yield strength. | 90 | 275 | 14 | 55 HB | 72 W/m·K |
As fabricated | Lowest-cost as-cast condition for non-critical housings and covers where ductility and strength are not driving. | 97 | 165 | 2.5 | 60 HB | 51 W/m·K |
T5This page Cooled from hot working and artificially aged | Low-distortion, low-cost aging of as-cast parts giving a modest hardness/yield gain without a solution soak. | 110 | 165 | 2 | 66 HB | 10 % IACS |
T6Default Solution heat treated and artificially aged | Standard structural condition: best combination of yield strength, hardness and fatigue for gearbox and housing castings. | 145 | 275 | 6 | 70 HB | 72 W/m·K |
What is AZ91E-T5?
AZ91E-T5 is AZ91E in the T5 temper — low-distortion, low-cost aging of as-cast parts giving a modest hardness/yield gain without a solution soak. AZ91E-T5 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 83% of magnesium alloy grades. Elongation at break is 2% and the elastic modulus is 45 GPa (6.53 Msi). AZ91E-T5 has a density of 1.81 g/cm³ (0.0654 lb/in³), heavier than 58% of magnesium alloy grades. It melts at 470°C (878 °F). T6 is the default condition FabDigit quotes; T5 is available on request or by drawing note.
Limitations
- Low fracture toughness — 11 MPa·√m (10 ksi·√in), worse than 100% of magnesium alloy grades
- Limited ductility — 2%, worse than 99% of magnesium alloy grades
- Low electrical conductivity — 10 % IACS, worse than 99% of magnesium alloy grades
- Poor heat conductor — 60 W/m·K (34.7 BTU/hr·ft·°F), worse than 88% of magnesium alloy grades
- Low strength — 110 MPa (16 ksi), worse than 83% of magnesium alloy grades
AZ91E-T5 properties
Typical room-temperature values for AZ91E-T5; 20 are specific to this condition. Other listed values are AZ91E reference data and may not represent this condition. Bars are the position among magnesium alloy grades.
Physical3
AZ91E-T5 has a density of 1.81 g/cm³ (0.0654 lb/in³), heavier than 58% of magnesium alloy grades. It melts at 470°C (878 °F).
Mechanical14
AZ91E-T5 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 83% of magnesium alloy grades. Elongation at break is 2% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
AZ91E-T5 is rated for continuous service to 130°C (266 °F). It conducts heat at 60 W/m·K (34.7 BTU/hr·ft·°F), worse than 88% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
AZ91E-T5 conducts electricity at 10 % IACS, worse than 99% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), better than 88% of magnesium alloy grades.
Sustainability4
Producing a kilogram of AZ91E-T5 takes about 330 MJ of energy and emits 30 kg of CO₂ — less than 56% of magnesium alloy grades. Typical recycled content is 15%.
Manufacturability8
AZ91E-T5's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability good (65/100); formability not recommended (8/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AZ91E-T5
Is AZ91E easy to machine?
Cuts extremely freely at high speed with sharp positive-rake tools and low forces; use dry or mineral-oil cutting (never water-based) and manage fine chips/dust for fire risk.
Can AZ91E be welded?
Readily GTAW/GMAW welded with AZ92A or AZ101A filler under Ar; preheat thick sections and re-solution/age or stress-relieve to restore properties and avoid SCC.
Can AZ91E be formed, bent or molded?
Sand and permanent-mold casting alloy with excellent fluidity; needs SF6-free protective cover gas or flux, generous feeding and hot-tearing-aware gating — no cold forming.
What surface finishes work on AZ91E?
Requires chromate-free conversion coating (or Dow 17 / HAE / PEO) plus epoxy primer and topcoat; isolate all steel/aluminium fasteners to prevent galvanic attack.
AZ91E chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Al | 8.1 – 9.3 | 8.7 |
| Zn | 0.4 – 1 | 0.7 |
| Mnmin Mn also tied to Fe/Mn ratio control | 0.17 – 0.35 | 0.25 |
| Si | ≤ 0.2 | — |
| Cuhigh-purity limit vs 0.10 for AZ91C | ≤ 0.02 | — |
| Nihigh-purity limit | ≤ 0 | — |
| Fehigh-purity limit — key to corrosion performance | ≤ 0.01 | — |
| Other (each) | ≤ 0.01 | — |
| Others (total) | ≤ 0.3 | — |
| Mg | balance | — |
AZ91E-T5 — frequently asked
What is AZ91E-T5 used for?
AZ91E-T5 is typically used for structural sand castings, aerospace and helicopter gearbox housings, corrosion-exposed equipment enclosures, permanent-mold pump and valve bodies, motorsport suspension and chassis castings and portable equipment frames. In short: high-purity AZ91 casting grade; best ductility in family; weldable structural magnesium.
What is the yield strength of AZ91E-T5?
AZ91E-T5 has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 83% of magnesium alloy grades. Strength varies by condition: see the 4 listed tempers.
Is AZ91E-T5 easy to machine?
Yes — machinability is rated excellent (95/100, better than 54% of magnesium alloy grades). Cuts extremely freely at high speed with sharp positive-rake tools and low forces; use dry or mineral-oil cutting (never water-based) and manage fine chips/dust for fire risk.
Can AZ91E-T5 be welded?
Yes — weldability is rated good (65/100). Readily GTAW/GMAW welded with AZ92A or AZ101A filler under Ar; preheat thick sections and re-solution/age or stress-relieve to restore properties and avoid SCC.
What surface finishes work on AZ91E-T5?
Requires chromate-free conversion coating (or Dow 17 / HAE / PEO) plus epoxy primer and topcoat; isolate all steel/aluminium fasteners to prevent galvanic attack.
Can AZ91E-T5 be formed, bent or molded?
Sand and permanent-mold casting alloy with excellent fluidity; needs SF6-free protective cover gas or flux, generous feeding and hot-tearing-aware gating — no cold forming.
What is the maximum service temperature of AZ91E-T5?
AZ91E-T5 is rated for continuous use to about 130°C (266 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AZ91E-T6 and AZ91E-T4?
T6 is the default condition — standard structural condition: best combination of yield strength, hardness and fatigue for gearbox and housing castings. T4: pick when maximum ductility, toughness and impact resistance matter more than yield strength. Yield strength is 145 MPa in T6 versus 90 MPa in T4.
Sources
- ASTM B80 — Magnesium-Alloy Sand Castings — ASTM International (2015)
- ASTM B199 — Magnesium-Alloy Permanent Mold Castings — ASTM International (2019)
- ASTM B93/B93M — Magnesium Alloys in Ingot Form for Sand, Permanent Mold and Die Castings — ASTM International (2020)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys — ASM International (1999)
- SAE AMS 4446 / UNS M11919 designation data — SAE International (2018)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.