Magnesium Alloy ZM6-T6
Temper · default condition
T6 = solution heat treated and artificially aged
Standard delivery condition for ZM6 sand castings; the only condition with strength values in GB/T 1177.
Values for the T6 condition
Other ZM6 tempers and conditions
ZM6 is listed in 3 conditions; see the grade overview at ZM6.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Rarely specified for ZM6 — only for non-structural or dimensionally sensitive parts where the T6 cycle is not allowed. | 95 | 165 | 3 | 55 HB | 23 % IACS |
T6DefaultThis page Solution heat treated and artificially aged | Standard delivery condition for ZM6 sand castings; the only condition with strength values in GB/T 1177. | 145 | 250 | 4.5 | 70 HB | 25 % IACS |
T6 | Chill-cast (metal mould) sections give finer structure and slightly higher strength and ductility than sand cast T6. | 150 | 265 | 5.5 | 73 HB | 26 % IACS |
What is ZM6-T6?
ZM6-T6 is ZM6 in the T6 temper — standard delivery condition for ZM6 sand castings; the only condition with strength values in GB/T 1177. ZM6-T6 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 250 MPa (36.3 ksi) — stronger than 51% of magnesium alloy grades. Elongation at break is 4.5% and the elastic modulus is 44 GPa (6.38 Msi). ZM6-T6 has a density of 1.8 g/cm³ (0.065 lb/in³), lighter than 63% of magnesium alloy grades. It melts at 545°C (1,013 °F).
Advantages
- High service temperature — 250°C (482 °F), better than 93% of magnesium alloy grades
ZM6-T6 properties
Typical room-temperature values for ZM6-T6; 21 are specific to this condition. Other listed values are ZM6 reference data and may not represent this condition. Bars are the position among magnesium alloy grades.
Physical3
ZM6-T6 has a density of 1.8 g/cm³ (0.065 lb/in³), lighter than 63% of magnesium alloy grades. It melts at 545°C (1,013 °F).
Mechanical15
ZM6-T6 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 250 MPa (36.3 ksi) — stronger than 51% of magnesium alloy grades. Elongation at break is 4.5% and the elastic modulus is 44 GPa (6.38 Msi).
Thermal6
ZM6-T6 is rated for continuous service to 250°C (482 °F). It conducts heat at 105 W/m·K (60.7 BTU/hr·ft·°F), better than 61% of magnesium alloy grades. Thermal expansion is 26.5 µm/m·K (14.7 µin/in·°F).
Electrical3
ZM6-T6 conducts electricity at 25 % IACS, better than 69% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 64% of magnesium alloy grades.
Sustainability4
Producing a kilogram of ZM6-T6 takes about 340 MJ of energy and emits 30 kg of CO₂ — more than 59% of magnesium alloy grades. Typical recycled content is 15%.
Manufacturability8
ZM6-T6's machinability is excellent (92/100, worse than 86% of magnesium alloy grades); weldability good (65/100); formability not recommended (8/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZM6-T6
Is ZM6 easy to machine?
Machines very freely at high speed with sharp positive-rake tools and no coolant mist that can ignite fines — collect chips wet-free and keep class-D extinguisher on hand.
Can ZM6 be welded?
Good GTAW/GMAW weldability with matching ZM6 or EZ33-type filler; re-solution + age after major repair welds to restore properties.
Can ZM6 be formed, bent or molded?
A casting alloy only — Zr-refined melt, sand or permanent mould, protected by SF6-free cover gas; feeds well with low microporosity but needs 530 °C solution in protective atmosphere.
What surface finishes work on ZM6?
Never bare in service: chemical conversion coating, Dow 17/HAE or PEO anodize plus epoxy primer; insulate all steel/aluminium fasteners to avoid galvanic attack.
ZM6 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 |
|---|---|---|
| Ndrare earth, predominantly neodymium (didymium) | 2 – 2.8 | 2.4 |
| Zn | 0.2 – 0.7 | 0.45 |
| Zrgrain refiner | 0.4 – 1 | 0.6 |
| Siimpurity max | ≤ 0.01 | — |
| Feimpurity max | ≤ 0.01 | — |
| Cuimpurity max | ≤ 0.03 | — |
| Niimpurity max | ≤ 0.01 | — |
| Alimpurity max | ≤ 0.02 | — |
| Mgbalance; total impurities typically ≤0.30 % | balance | — |
ZM6-T6 — frequently asked
What is ZM6-T6 used for?
ZM6-T6 is typically used for aircraft gearbox housings, missile components, aero-engine accessory casings, high-temperature structural castings, cast covers and sumps and pressure-tight housings. In short: best strength/creep balance; silver-bearing, higher cost; 250 °C aerospace castings.
What is the yield strength of ZM6-T6?
ZM6-T6 has a typical yield strength of 145 MPa (21 ksi) and a tensile strength of 250 MPa (36.3 ksi) — stronger than 51% of magnesium alloy grades. Strength varies by condition: see the 3 listed tempers.
Is ZM6-T6 easy to machine?
Yes — machinability is rated excellent (92/100, worse than 86% of magnesium alloy grades). Machines very freely at high speed with sharp positive-rake tools and no coolant mist that can ignite fines — collect chips wet-free and keep class-D extinguisher on hand.
Can ZM6-T6 be welded?
Yes — weldability is rated good (65/100). Good GTAW/GMAW weldability with matching ZM6 or EZ33-type filler; re-solution + age after major repair welds to restore properties.
What surface finishes work on ZM6-T6?
Never bare in service: chemical conversion coating, Dow 17/HAE or PEO anodize plus epoxy primer; insulate all steel/aluminium fasteners to avoid galvanic attack.
Can ZM6-T6 be formed, bent or molded?
A casting alloy only — Zr-refined melt, sand or permanent mould, protected by SF6-free cover gas; feeds well with low microporosity but needs 530 °C solution in protective atmosphere.
What is the maximum service temperature of ZM6-T6?
ZM6-T6 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZM6-T6 and ZM6-F?
T6 is the default condition — standard delivery condition for ZM6 sand castings; the only condition with strength values in GB/T 1177. F: rarely specified for ZM6 — only for non-structural or dimensionally sensitive parts where the T6 cycle is not allowed. Yield strength is 145 MPa in T6 versus 95 MPa in F.
Sources
- 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.