Magnesium Alloy ZC63-T6
Temper · default condition
ASTM ZC63 · EN MC32110, MgZn6Cu3Mn
T6 = solution heat treated and artificially aged
Standard supply condition for ZC63A structural sand castings — best combination of strength, ductility and pressure tightness.
Values for the T6 condition
Other ZC63 tempers and conditions
ZC63 is listed in 4 conditions; see the grade overview at ZC63.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest-cost condition for lightly stressed or dimensionally critical castings where the T6 cycle cannot be tolerated. | 105 | 165 | 3 | 52 HB | 27 % IACS |
Solution heat treated and naturally aged | Choose when maximum ductility and impact toughness matter more than yield strength. | 110 | 205 | 8 | 55 HB | 25 % IACS |
T6DefaultThis page Solution heat treated and artificially aged | Standard supply condition for ZC63A structural sand castings — best combination of strength, ductility and pressure tightness. | 145 | 240 | 5 | 62 HB | 122 W/m·K |
T6 | Pick for higher-volume chill castings where the finer as-cast structure lifts strength and elongation above sand-cast T6. | 150 | 250 | 6 | 65 HB | 29 % IACS |
What is ZC63-T6?
ZC63-T6 is ZC63 in the T6 temper — standard supply condition for ZC63A structural sand castings — best combination of strength, ductility and pressure tightness. ZC63-T6 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 240 MPa (34.8 ksi) — stronger than 51% of magnesium alloy grades. Elongation at break is 5% and the elastic modulus is 45 GPa (6.53 Msi). ZC63-T6 has a density of 1.87 g/cm³ (0.0676 lb/in³), heavier than 99% of magnesium alloy grades. It melts at 465°C (869 °F).
Advantages
- High electrical conductivity — 29 % IACS, better than 91% of magnesium alloy grades
- Conducts heat well — 122 W/m·K (70.5 BTU/hr·ft·°F), better than 88% of magnesium alloy grades
Limitations
- Difficult to weld — 35/100, worse than 80% of magnesium alloy grades
- Limited service temperature — 120°C (248 °F), worse than 78% of magnesium alloy grades
ZC63-T6 properties
Typical room-temperature values for ZC63-T6; 12 are specific to this condition. Other listed values are ZC63 reference data and may not represent this condition. Bars are the position among magnesium alloy grades.
Physical3
ZC63-T6 has a density of 1.87 g/cm³ (0.0676 lb/in³), heavier than 99% of magnesium alloy grades. It melts at 465°C (869 °F).
Mechanical12
ZC63-T6 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 240 MPa (34.8 ksi) — stronger than 51% of magnesium alloy grades. Elongation at break is 5% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
ZC63-T6 is rated for continuous service to 120°C (248 °F). It conducts heat at 122 W/m·K (70.5 BTU/hr·ft·°F), better than 88% of magnesium alloy grades. Thermal expansion is 27 µm/m·K (15 µin/in·°F).
Electrical3
ZC63-T6 conducts electricity at 29 % IACS, better than 91% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), worse than 57% of magnesium alloy grades.
Sustainability4
Producing a kilogram of ZC63-T6 takes about 320 MJ of energy and emits 33 kg of CO₂ — less than 74% of magnesium alloy grades. Typical recycled content is 20%.
Manufacturability8
ZC63-T6's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability fair (35/100); formability not recommended (10/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZC63-T6
Is ZC63 easy to machine?
Cuts extremely freely at high speed with sharp positive-rake tooling; use dry or mineral-oil coolant (never water-based) and keep fine chips/dust collected wet to avoid ignition.
Can ZC63 be welded?
TIG/GMAW with matching or EZ33-type filler is possible but Zn+Cu make the alloy hot-crack sensitive; preheat, minimise restraint and re-solution treat repairs where strength matters.
Can ZC63 be formed, bent or molded?
A casting alloy only — sand and permanent-mold with careful gating/risering for pressure tightness; grain refine and degas the melt, and protect with SF6-free cover gas.
What surface finishes work on ZC63?
Chromate or chrome-free conversion coating, HAE/plasma-electrolytic anodize or e-coat plus paint is essential; isolate from steel/aluminium fasteners to prevent galvanic attack.
ZC63 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 |
|---|---|---|
| Znprincipal strengthening addition | 5.5 – 6.5 | 6 |
| Curefines interdendritic phase, improves pressure tightness; degrades corrosion | 2.4 – 3 | 2.7 |
| Mniron control / corrosion mitigation | 0.25 – 0.75 | 0.5 |
| Si | ≤ 0.2 | — |
| Fe | ≤ 0.05 | — |
| Ni | ≤ 0.01 | — |
| Others (each)max each | ≤ 0.01 | — |
| Others (total)max total | ≤ 0.3 | — |
| Mg | balance | — |
ZC63-T6 — frequently asked
What is ZC63-T6 used for?
ZC63-T6 is typically used for pump housings, structural aerospace castings and gearbox housings. In short: heat-treatable cast magnesium; good pressure tightness; machines faster than aluminium.
What is the yield strength of ZC63-T6?
ZC63-T6 has a typical yield strength of 145 MPa (21 ksi) and a tensile strength of 240 MPa (34.8 ksi) — stronger than 51% of magnesium alloy grades. Strength varies by condition: see the 4 listed tempers.
Is ZC63-T6 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 tooling; use dry or mineral-oil coolant (never water-based) and keep fine chips/dust collected wet to avoid ignition.
Can ZC63-T6 be welded?
With care — weldability is rated fair (35/100). TIG/GMAW with matching or EZ33-type filler is possible but Zn+Cu make the alloy hot-crack sensitive; preheat, minimise restraint and re-solution treat repairs where strength matters.
What surface finishes work on ZC63-T6?
Chromate or chrome-free conversion coating, HAE/plasma-electrolytic anodize or e-coat plus paint is essential; isolate from steel/aluminium fasteners to prevent galvanic attack.
Can ZC63-T6 be formed, bent or molded?
A casting alloy only — sand and permanent-mold with careful gating/risering for pressure tightness; grain refine and degas the melt, and protect with SF6-free cover gas.
What is the maximum service temperature of ZC63-T6?
ZC63-T6 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZC63-T6 and ZC63-F?
T6 is the default condition — standard supply condition for ZC63A structural sand castings — best combination of strength, ductility and pressure tightness. F: lowest-cost condition for lightly stressed or dimensionally critical castings where the T6 cycle cannot be tolerated. Yield strength is 145 MPa in T6 versus 105 MPa in F.
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 Castings — ASTM International (2021)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys — ASM International (1999)
- 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.