Magnesium Alloy ML5-T1
Temper
T1 = cooled from hot working and naturally aged
Simple ageing of the as-cast part to raise yield strength and stabilise dimensions without a solution treatment.
Values for the T1 condition
Other ML5 tempers and conditions
ML5 is listed in 5 conditions; see the grade overview at ML5.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Cooled from hot working, cold worked and naturally aged | Use when residual stress from casting, welding or heavy machining must be removed and strength is secondary. | 85 | 160 | 3 | 52 HB | 13 % IACS |
T4Default Solution heat treated and naturally aged | Standard aerospace condition for ML5 castings — best combination of strength, ductility and impact resistance. | 95 | 260 | 8 | 60 HB | 72 W/m·K |
As fabricated | Lowest cost condition for lightly loaded housings and covers where ductility is not critical. | 95 | 165 | 2.5 | 55 HB | 72 W/m·K |
T1This page Cooled from hot working and naturally aged | Simple ageing of the as-cast part to raise yield strength and stabilise dimensions without a solution treatment. | 110 | 195 | 2 | 65 HB | 12.5 % IACS |
Solution heat treated and artificially aged | Pick when maximum yield strength, hardness and dimensional stability matter more than ductility. | 135 | 275 | 4 | 70 HB | 72 W/m·K |
What is ML5-T1?
ML5-T1 is ML5 in the T1 temper — simple ageing of the as-cast part to raise yield strength and stabilise dimensions without a solution treatment. ML5-T1 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 83% of magnesium alloy grades. Elongation at break is 2% and the elastic modulus is 45 GPa (6.53 Msi). ML5-T1 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). T4 is the default condition FabDigit quotes; T1 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 strength — 110 MPa (16 ksi), worse than 83% of magnesium alloy grades
ML5-T1 properties
Typical room-temperature values for ML5-T1; 20 are specific to this condition. Other listed values are ML5 reference data and may not represent this condition. Bars are the position among magnesium alloy grades.
Physical3
ML5-T1 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).
Mechanical13
ML5-T1 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 83% of magnesium alloy grades. Elongation at break is 2% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
ML5-T1 is rated for continuous service to 130°C (266 °F). It conducts heat at 75 W/m·K (43.3 BTU/hr·ft·°F), worse than 59% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
ML5-T1 conducts electricity at 12.5 % IACS, worse than 68% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), worse than 88% of magnesium alloy grades.
Sustainability4
Producing a kilogram of ML5-T1 takes about 320 MJ of energy and emits 30 kg of CO₂ — less than 74% of magnesium alloy grades. Typical recycled content is 30%.
Manufacturability8
ML5-T1's machinability is excellent (97/100, better than 92% of magnesium alloy grades); weldability good (60/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ML5-T1
Is ML5 easy to machine?
Outstanding machinability with sharp, high-rake tooling and high speeds; use dry or mineral-oil cutting (never water-based) and manage fine chips against fire risk.
Can ML5 be welded?
Readily GTAW/GMAW welded with AZ92A or AZ101 filler in argon; preheat thick sections and stress-relieve or re-solution treat after welding.
Can ML5 be formed, bent or molded?
Sand and permanent-mould casting alloy with good fluidity and low hot-tearing tendency; melt must be flux- or SF6/SO2-protected and grain refined by superheat.
What surface finishes work on ML5?
No conventional anodizing — use chromate/Dow 17/HAE conversion coatings or plasma-electrolytic oxidation, then epoxy primer and paint; isolate from steel and aluminium fasteners to avoid galvanic attack.
ML5 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 |
|---|---|---|
| Alprimary strengthening element (Mg17Al12) | 7.5 – 9 | 8.3 |
| Zn | 0.2 – 0.8 | 0.5 |
| Mncontrols Fe for corrosion resistance | 0.15 – 0.5 | 0.3 |
| Siimpurity | ≤ 0.25 | — |
| Cuimpurity | ≤ 0.1 | — |
| Feimpurity | ≤ 0.06 | — |
| Niimpurity, strongly harmful to corrosion | ≤ 0.01 | — |
| Bemelt oxidation inhibitor | ≤ 0 | — |
| Mg | balance | — |
ML5-T1 — frequently asked
What is ML5-T1 used for?
ML5-T1 is typically used for gearbox housings, aircraft fitting castings and machinery housings. In short: best-machining cast magnesium; weldable AZ91C-type casting; heat-treatable to T6.
What is the yield strength of ML5-T1?
ML5-T1 has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 83% of magnesium alloy grades. Strength varies by condition: see the 5 listed tempers.
Is ML5-T1 easy to machine?
Yes — machinability is rated excellent (97/100, better than 92% of magnesium alloy grades). Outstanding machinability with sharp, high-rake tooling and high speeds; use dry or mineral-oil cutting (never water-based) and manage fine chips against fire risk.
Can ML5-T1 be welded?
Yes — weldability is rated good (60/100). Readily GTAW/GMAW welded with AZ92A or AZ101 filler in argon; preheat thick sections and stress-relieve or re-solution treat after welding.
What surface finishes work on ML5-T1?
No conventional anodizing — use chromate/Dow 17/HAE conversion coatings or plasma-electrolytic oxidation, then epoxy primer and paint; isolate from steel and aluminium fasteners to avoid galvanic attack.
Can ML5-T1 be formed, bent or molded?
Sand and permanent-mould casting alloy with good fluidity and low hot-tearing tendency; melt must be flux- or SF6/SO2-protected and grain refined by superheat.
What is the maximum service temperature of ML5-T1?
ML5-T1 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 ML5-T4 and ML5-T6?
T4 is the default condition — standard aerospace condition for ML5 castings — best combination of strength, ductility and impact resistance. T6: pick when maximum yield strength, hardness and dimensional stability matter more than ductility. Yield strength is 95 MPa in T4 versus 135 MPa in T6.
Sources
- GOST 2856-79 Magnesium casting alloys — grades — Gosstandart (1979)
- ASTM B80 / ASTM B403 Magnesium-Alloy Sand and Investment Castings (AZ91C/AZ91E) — 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)
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.