Magnesium Alloy ZM3
ZM3 is a rare-earth magnesium casting alloy of the Mg-RE-Zn-Zr system, comparable to EZ33A, where the rare-earth phases at the grain boundaries provide creep resistance rather than room-temperature strength.
Reference datasheet — ZM3 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the T1 condition
ZM3 tempers and conditions
ZM3 is supplied in 2 conditions, soft to hard. T1 is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Pick for non-critical or low-stress parts where the aging cycle is skipped; slightly lower yield strength than T1. | 80 | 130 | 3.5 | 50 HB | 22 % IACS |
T1Default Cooled from hot working and naturally aged | Standard supply condition: ~200 °C/8–16 h aging that precipitates the RE phases, giving the best creep and elevated-temperature stability. | 95 | 145 | 3 | 55 HB | 24 % IACS |
What is ZM3?
ZM3 is a rare-earth magnesium casting alloy of the Mg-RE-Zn-Zr system, comparable to EZ33A, where the rare-earth phases at the grain boundaries provide creep resistance rather than room-temperature strength. It is cast in F and T1 conditions and chosen for pressure-tight housings that run hot, with a 250 °C maximum service temperature. Room-temperature properties are modest at 95 MPa yield, 145 MPa tensile, 3% elongation and 55 HB, so where higher strength is needed at similar temperature ZM6 (QE22A) is the nearest alternative. ZM3 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). ZM3 has a yield strength of 95 MPa (13.8 ksi) and a tensile strength of 145 MPa (21 ksi) — weaker than 93% of magnesium alloy grades. Elongation at break is 3% and the elastic modulus is 44 GPa (6.38 Msi).
What is ZM3 used for?
- Aero-engine casings
- High-temperature cast housings
- Gearbox and accessory drive casings
- Pressure-tight pump bodies
- Engine-mounted brackets and covers
Advantages
- High service temperature — 250°C (482 °F), better than 93% of magnesium alloy grades
Limitations
- Low strength — 95 MPa (13.8 ksi), worse than 93% of magnesium alloy grades
- Low fracture toughness — 12 MPa·√m (10.9 ksi·√in), worse than 92% of magnesium alloy grades
- Limited ductility — 3%, worse than 85% of magnesium alloy grades
ZM3 properties
Typical room-temperature values for ZM3-T1; bars are the position among magnesium alloy grades.
Physical3
ZM3 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
ZM3 has a yield strength of 95 MPa (13.8 ksi) and a tensile strength of 145 MPa (21 ksi) — weaker than 93% of magnesium alloy grades. Elongation at break is 3% and the elastic modulus is 44 GPa (6.38 Msi).
Thermal6
ZM3 is rated for continuous service to 250°C (482 °F). It conducts heat at 100 W/m·K (57.8 BTU/hr·ft·°F), better than 57% of magnesium alloy grades. Thermal expansion is 26.5 µm/m·K (14.7 µin/in·°F).
Electrical3
ZM3 conducts electricity at 24 % IACS, better than 58% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), worse than 57% of magnesium alloy grades.
Sustainability4
Producing a kilogram of ZM3 takes about 330 MJ of energy and emits 32 kg of CO₂ — less than 56% of magnesium alloy grades. Typical recycled content is 25%.
Manufacturability8
ZM3'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. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the magnesium alloy family
Yield strength against density for every magnesium alloy grade FabDigit runs. ZM3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZM3
Is ZM3 easy to machine?
Extremely free machining with sharp, high-rake carbide tools and high speeds; use dry or mineral-oil coolant (never water-based) and control fine chips/dust for fire risk.
Can ZM3 be welded?
Good TIG/GTAW weldability with matching RE-Mg filler under argon; low hot-cracking tendency, re-age after welding to restore creep properties.
Can ZM3 be formed, bent or molded?
Sand and permanent-mould casting alloy with excellent fluidity and pressure tightness; melt under SF6/SO2 or inert cover, keep Fe/Ni/Cu impurities low, not cold formable.
ZM3 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 |
|---|---|---|
| RE (mischmetal, Ce-rich)cerium-rich mischmetal | 2.5 – 4 | 3 |
| Zn | 0.2 – 0.7 | 0.5 |
| Zrgrain refiner | 0.4 – 1 | 0.7 |
| Siimpurity max | ≤ 0.02 | |
| Feimpurity max | ≤ 0.01 | |
| Cuimpurity max | ≤ 0.03 | |
| Niimpurity max | ≤ 0.01 | |
| Mg | balance |
What surface finishes work on ZM3?
Requires chemical conversion (chromate-free) or MAO/HAE anodic coating plus epoxy primer/topcoat; insulate all steel and copper-alloy fasteners to prevent galvanic corrosion.
Equivalent designations
Standards and trade names that resolve to Magnesium Alloy ZM3 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- EZ33A
How much does ZM3 cost?
ZM3 is a premium-cost magnesium alloy ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ZM3 — frequently asked
What is ZM3 used for?
ZM3 is typically used for aero-engine casings, high-temperature cast housings, gearbox and accessory drive casings, pressure-tight pump bodies and engine-mounted brackets and covers. In short: creep-resistant Mg casting; 250 °C service capability; low hot-cracking tendency.
What is the yield strength of ZM3?
ZM3 has a typical yield strength of 95 MPa (13.8 ksi) and a tensile strength of 145 MPa (21 ksi) — weaker than 93% of magnesium alloy grades. Strength varies by condition: see the 2 listed tempers.
Is ZM3 easy to machine?
Yes — machinability is rated excellent (92/100, worse than 86% of magnesium alloy grades). Extremely free machining with sharp, high-rake carbide tools and high speeds; use dry or mineral-oil coolant (never water-based) and control fine chips/dust for fire risk.
Can ZM3 be welded?
Yes — weldability is rated good (65/100). Good TIG/GTAW weldability with matching RE-Mg filler under argon; low hot-cracking tendency, re-age after welding to restore creep properties.
What surface finishes work on ZM3?
Requires chemical conversion (chromate-free) or MAO/HAE anodic coating plus epoxy primer/topcoat; insulate all steel and copper-alloy fasteners to prevent galvanic corrosion.
Can ZM3 be formed, bent or molded?
Sand and permanent-mould casting alloy with excellent fluidity and pressure tightness; melt under SF6/SO2 or inert cover, keep Fe/Ni/Cu impurities low, not cold formable.
What is the maximum service temperature of ZM3?
ZM3 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 ZM3-T1 and ZM3-F?
T1 is the default condition — standard supply condition: ~200 °C/8–16 h aging that precipitates the RE phases, giving the best creep and elevated-temperature stability. F: pick for non-critical or low-stress parts where the aging cycle is skipped; slightly lower yield strength than T1. Yield strength is 95 MPa in T1 versus 80 MPa in F.
How much does ZM3 cost?
ZM3 is a premium-cost magnesium alloy ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B80 Standard Specification for Magnesium-Alloy Sand Castings — ASTM (2020)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (Magnesium casting alloys, EZ33A) — 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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.