Magnesium Alloy EV31A · temper
Magnesium Alloy EV31A-T6
Properties of the T6 condition, compared with the other EV31A tempers.
Standard supply and design condition for aerospace EV31A castings (AMS 4429 / ASTM B80) — best combination of room- and elevated-temperature strength.
What is EV31A-T6?
EV31A-T6 is EV31A in the T6 temper — standard supply and design condition for aerospace EV31A castings (AMS 4429 / ASTM B80) — best combination of room- and elevated-temperature strength. EV31A-T6 has a yield strength of 172 MPa (24.9 ksi) and a tensile strength of 280 MPa (40.6 ksi) — stronger than 71% of magnesium alloy grades. Elongation at break is 5% and the elastic modulus is 44 GPa (6.38 Msi). EV31A-T6 has a density of 1.82 g/cm³ (0.0658 lb/in³), heavier than 74% of magnesium alloy grades. It melts at 545°C (1,013 °F). As Cast is the default condition FabDigit quotes; T6 is available on request or by drawing note.
Advantages
- Good corrosion resistance — 32/100, better than 96% of magnesium alloy grades
- Tough — resists crack growth — 17 MPa·√m (15.5 ksi·√in), better than 93% of magnesium alloy grades
- High service temperature — 200°C (392 °F), better than 84% of magnesium alloy grades
Limitations
- High embodied carbon — 42 kg CO₂/kg, worse than 99% of magnesium alloy grades
- Low electrical conductivity — 11 % IACS, worse than 98% of magnesium alloy grades
EV31A-T6 properties
Typical room-temperature values for EV31A-T6 — 10 properties are specific to this condition; the rest are grade-level values shared by every EV31A temper. Each bar shows where the value sits among the magnesium alloy grades in FabDigit's library — further right is higher.
Physical3
EV31A-T6 has a density of 1.82 g/cm³ (0.0658 lb/in³), heavier than 74% of magnesium alloy grades. It melts at 545°C (1,013 °F).
Mechanical14
EV31A-T6 has a yield strength of 172 MPa (24.9 ksi) and a tensile strength of 280 MPa (40.6 ksi) — stronger than 71% of magnesium alloy grades. Elongation at break is 5% and the elastic modulus is 44 GPa (6.38 Msi).
Thermal6
EV31A-T6 is rated for continuous service to 200°C (392 °F). It conducts heat at 110 W/m·K (63.6 BTU/hr·ft·°F), better than 65% of magnesium alloy grades. Thermal expansion is 26.7 µm/m·K (14.8 µin/in·°F).
Electrical3
EV31A-T6 conducts electricity at 11 % IACS, worse than 98% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), better than 96% of magnesium alloy grades.
Sustainability4
Producing a kilogram of EV31A-T6 takes about 400 MJ of energy and emits 42 kg of CO₂ — more than 98% of magnesium alloy grades. Typical recycled content is 15%.
Manufacturability8
EV31A-T6's machinability is excellent (88/100, worse than 99% of magnesium alloy grades); weldability very good (72/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other EV31A tempers and conditions
EV31A is also supplied in 1 other condition. The full side-by-side table is on the EV31A overview.
- As CastDefaultUntreated foundry condition, used only for non-structural parts or as the starting point before T6 solution treatment and ageing.110 MPa yield · 55 HB
- T6Standard supply and design condition for aerospace EV31A castings (AMS 4429 / ASTM B80) — best combination of room- and elevated-temperature strength.172 MPa yield · 70 HB
Working with EV31A-T6
Is EV31A easy to machine?
Machines very easily with sharp carbide tools, high speeds and generous rake; use dry or mineral-oil coolant (never water-based) and manage fine chips to avoid ignition.
Can EV31A be welded?
TIG/GTAW repair-weldable with matching EV31A filler under argon; solution/ageing (T6) should be re-applied or a local post-weld age used to restore properties.
Can EV31A be formed, bent or molded?
Sand, investment and permanent-mould casting alloy with good fluidity and low hot-tearing tendency; use protective cover gas (SF6-free alternatives) and 0.6–1.0 % Zr grain refinement — not a wrought/formable alloy.
What surface finishes work on EV31A?
Apply chromate-free conversion coat plus epoxy primer/topcoat, or plasma-electrolytic (Keronite/Tagnite) coating; insulate all joints to steel or carbon fibre to prevent galvanic attack.
EV31A 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 |
|---|---|---|
| Ndprincipal RE strengthener | 2.6 – 3.1 | 2.85 |
| Gdheavy RE for elevated-temperature stability | 1 – 1.7 | 1.3 |
| Zn | 0.2 – 0.5 | 0.35 |
| Zrgrain refiner | 0.4 – 1 | 0.6 |
| Feimpurity limit | ≤ 0.01 | — |
| Cuimpurity limit | ≤ 0.03 | — |
| Niimpurity limit | ≤ 0.01 | — |
| Siimpurity limit | ≤ 0.01 | — |
| Others (each)total others 0.30 max | ≤ 0.01 | — |
| Mg | balance | — |
EV31A-T6 — frequently asked
What is EV31A-T6 used for?
EV31A-T6 is typically used for aircraft engine casings, helicopter transmission housings, motorsport gearbox castings, auxiliary gearbox covers, pump and actuator bodies and structural aerospace sand castings. In short: high-temp powertrain magnesium.
What is the yield strength of EV31A-T6?
EV31A-T6 has a typical yield strength of 172 MPa (24.9 ksi) and a tensile strength of 280 MPa (40.6 ksi) — stronger than 71% of magnesium alloy grades. Strength varies by condition: see the 2 listed tempers.
Is EV31A-T6 easy to machine?
Yes — machinability is rated excellent (88/100, worse than 99% of magnesium alloy grades). Machines very easily with sharp carbide tools, high speeds and generous rake; use dry or mineral-oil coolant (never water-based) and manage fine chips to avoid ignition.
Can EV31A-T6 be welded?
Yes — weldability is rated very good (72/100). TIG/GTAW repair-weldable with matching EV31A filler under argon; solution/ageing (T6) should be re-applied or a local post-weld age used to restore properties.
What surface finishes work on EV31A-T6?
Apply chromate-free conversion coat plus epoxy primer/topcoat, or plasma-electrolytic (Keronite/Tagnite) coating; insulate all joints to steel or carbon fibre to prevent galvanic attack.
Can EV31A-T6 be formed, bent or molded?
Sand, investment and permanent-mould casting alloy with good fluidity and low hot-tearing tendency; use protective cover gas (SF6-free alternatives) and 0.6–1.0 % Zr grain refinement — not a wrought/formable alloy.
What is the maximum service temperature of EV31A-T6?
EV31A-T6 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between EV31A As Cast and EV31A-T6?
As Cast is the default condition — untreated foundry condition, used only for non-structural parts or as the starting point before T6 solution treatment and ageing. T6: standard supply and design condition for aerospace EV31A castings (AMS 4429 / ASTM B80) — best combination of room- and elevated-temperature strength. Yield strength is 110 MPa in As Cast versus 172 MPa in T6.
Can FabDigit make parts in EV31A-T6?
Yes — EV31A-T6 is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Elektron 21 (EV31A) alloy datasheet — Magnesium Elektron / Luxfer MEL Technologies (2020)
- AMS 4429 — Magnesium Alloy Castings, EV31A-T6 — SAE International (2018)
- ASTM B80 — Standard Specification for Magnesium-Alloy Sand Castings — ASTM (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.