WE43 Magnesium
A yttrium and rare-earth magnesium alloy for high temperature
Typical values for the temper in the title
WE43 contains about 4% yttrium, about 3% rare earths (mainly neodymium) and zirconium. Unlike Mg-Al alloys, it keeps strength and creep resistance at high temperatures (up to about 250–300 °C), and has better corrosion resistance than most magnesium alloys.
It is used for helicopter gearbox housings, motorsport and aerospace engine parts, and in medical versions also for bioresorbable implants.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 250–280 MPa | |
| Yield strength Rp0.2 | 165–195 MPa | |
| Elongation A | 4% | |
| Hardness | 75 HB | |
| Modulus of elasticity E | 44 GPa | |
| Density ρ | 1.84 g/cm³ | |
| Machinability | 45% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| Y yttrium | 3.7–4.3 | hot strength |
| RE rare earths | 2.4–4.4 (Nd 2.0–2.5) | hot strength |
| Zr zirconium | min 0.4 | fine grains |
| Mg magnesium | balance |
Ranges per TMS data.
Tempers
WE43 is hardened by solution treatment and aging (T6).
| Temper | Properties | When to choose it |
|---|---|---|
| T6 (cast or wrought) | good strength, creep resistance when hot | gearbox housings and engine parts |
Applications
- Helicopter gearbox housings
- Aerospace engine parts
- Motorsport
- Bioresorbable implants (medical version)
- Light hot parts
Fabrication
Safety: fire
Fine chips, dust and grinding residue of magnesium are highly flammable and burn very hot. Use sharp tools and coarse chips, do not accumulate dust and chips, and keep a Class D extinguisher. Never use water: water intensifies the fire. A large solid part does not ignite easily.
Corrosion and galvanic contact
Magnesium is the least noble structural metal. In contact with steel, copper, stainless or even aluminum in the presence of moisture, it corrodes fast. Isolate contacts, protect with a conversion coating and paint, and use suitable fasteners.
Welding
Welds relatively well for magnesium (database: "Good").
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| EZ33A | 160 / 100 MPa | Good | an older rare-earth alloy for creep · material page |
| AZ91D | 230 / 160 MPa | Difficult — crack-prone | cheap, not for heat · material page |
| 242.0 | 220 / 180 MPa | Not possible | an aluminum casting alloy for heat · material page |
Common mistakes
Putting out a magnesium fire with water
Water intensifies the fire. Use a Class D extinguisher or dry sand.
Coupling directly to steel or stainless
Rapid galvanic corrosion of the magnesium.
Using a Mg-Al alloy in a hot part
Mg-Al alloys lose creep strength already around 120–150 °C. For heat, WE43.
Equivalents, standards and supply
| ASTM | B80 WE43 |
|---|---|
| Standards | ASTM B80 |
| Forms | casting · wrought · forging |
| Producers | Magnesium Elektron |
Learn more
Values are typical and for comparison only. For design, rely on the standard and the mill certificate. Sources: ASTM B80, B90, B91, B94 and B107, AMS specifications, Magnesium Elektron and TMS data, and the METAL HUB materials database.
Updated: October 31, 2026