Technical guide · 2026-08-14
Magnesium-Zinc-Zirconium Alloys
ZK alloys combine zinc strengthening with zirconium grain refinement for high-strength wrought products, while forgeability, texture and stress-corrosion behavior limit direct substitution for AZ systems.
01
Definition and boundary
Covers zirconium-refined Mg-Zn wrought systems; excludes rare-earth ZE/WE families and cast-route assumptions.
Reference information only: final acceptance is controlled by the ordered product specification, condition, dimensions and certified test results.
02
How the material system works
Zirconium refines grains.
Zinc supports precipitation strengthening.
Working direction affects toughness.
03
Representative grades and systems
| Grade or system | Selection focus | Qualification |
|---|---|---|
| ZK60A-T5 | Use ZK60A-T5 only with its governing product specification and condition. | Confirm the governing product specification, delivery condition, section size and acceptance tests before treating designations as interchangeable. |
| ZK60A-T6 | Use ZK60A-T6 only with its governing product specification and condition. | Confirm the governing product specification, delivery condition, section size and acceptance tests before treating designations as interchangeable. |
| ZK40A | Use ZK40A only with its governing product specification and condition. | Confirm the governing product specification, delivery condition, section size and acceptance tests before treating designations as interchangeable. |
04
Properties and trade-offs
High wrought strength
Fatigue response
Directional toughness
05
Product forms and supply conditions
06
Applications and selection
Applications and selection
- Helicopter gear parts
- Forged wheels
- High-strength extrusions
Properties and trade-offs
- Set strength without overaging toughness.
- Review stress-corrosion exposure.
- Map grain flow in forgings.
07
Fabrication, durability and inspection
Control billet cleanliness.
Qualify forging temperature.
Remove sharp machining marks.
08
Procurement checklist
- State ZK60A and exact temper.
- Define grain flow and test direction.
- Specify ultrasonic, finish and corrosion protection.
09
Standards, sources and review
Standards and designation context
- Applicable ASTM B07.04 product specification
- ASTM B296 temper practice
- Buyer drawing and acceptance plan