Magnesium Alloys
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Attributes
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Limitations
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Applications
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AZ91
AZ91E
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 Most commercially used magnesium alloy- Low cost alloy
- New high purity version, AZ91E, provides excellent general corrosion resistance
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- Castability is moderate in terms of shrinkage and segregation
- Prone to micro shrinkage, affects pressure tightness
- Moderate mechanical properties further reduced in thicker section castings
- Ambient temperature alloy limited to 220° F max. service
- Requires T6 heat treatment
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- Used where moderate strength, low operational temperatures and cost are significant factors
- AZ91E offers much improved corrosion performance
- Aircraft controls, brackets, transmission housings and wheels
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AZ92
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- Improved room temperature tensile properties compared to AZ91 due to higher zinc content
- Corrosion resistant high purity version possible, but more difficult to achieve
- Low cost alloy
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- Castability similar to AZ91
- Improved mechanical properties still limited by elevated temperature
- Requires T6 heat treatment
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- Same as AZ91 applications, but with higher stress requirements
- Thrust reverse cascades
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ZE41
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- Good castability and pressure tightness - producer friendly
- *Zr grain refined alloy
- Elevated temperature capable up to 350° F
- Moderate cost alloy
- Used in T5 condition
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- Moderate strength alloy
- Moderate general corrosion alloy
- Rare earth segregation more noticeable on radiography
- More prone to oxide type linear indications than AZ alloys
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- Widely used, pressure tight, medium strength, elevated temperature alloy
- Engine castings, APUs, helicopter transmission, generator housings, gearboxes
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QE22
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- Excellent high strength room temperature properties
- Good elevated temperature properties with application to 400° F
- *Zr grain refined alloy
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- More difficult to cast than ZE41
- High general corrosion rate
- High cost alloy due to silver content
- Requires T6 heat treatment with some susceptibility for quench cracking and distortion
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- Elevated temperature, high strength alloy
- Engine casings, generator housings, engine structural components, other hot running components
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WE43A
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- Good high strength room temperature alloys
- Excellent elevated temperature properties with application to 550° F
- Excellent general corrosion resistance
- *Zr grain refined alloy
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- The most difficult of magnesium alloys to cast (relatively early in the development cycle)
- Additional melt and casting controls required
- High cost alloy due to yttrium content
- Requires T6 heat treatment with susceptibility for quench cracking and distortion
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- Elevated temperature, high strength, creep resistant alloy. Also offering salt fog corrosion resistance
- Engine gearboxes, helicopter transmission cases
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EZ33
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- Excellent castability and pressure tightness - producer friendly
- *Zr grain refined alloy
- Excellent vibration damping capacity
- Elevated temperature capable to 475° F
- Moderate cost alloy
- Used in T5 condition
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- Low strength alloy
- Moderate general corrosion
- Rare earth segregation more noticeable on radiography
- More prone to oxide type linear indications than AZ alloys
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- Low strength applications requiring elevated temperature stability
- Best for combination of castability and vibration damping capacity
- Engine gear boxes, generator cases, vibration test fixtures
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*Zr (zirconium) refininement provides for more uniform mechanical properties in thin-to-thick sections.
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