Chemical composition
Reference GB/T5153-2016 (Designation and composition of wrought magnesium and magnesium alloys)
Grand |
Chemical composition (mass fraction)% |
|||||||||
Mg |
Al |
Zn |
Mn |
Ca |
Si |
Fe |
Cu |
Ni |
Other elements |
|
AZ31B |
Rest |
2.5-3.5 |
0.6-1.4 |
0.2-1 |
0.04 |
0.08 |
0.003 |
0.01 |
0.001 |
0.3 |
Among them, the addition of aluminum and zinc elements can improve the strength, castability and corrosion resistance of magnesium alloy. The addition of manganese improves corrosion resistance and neutralizes the effect of impurity iron. The rest of the impurity elements such as Fe, Cu, Ni and other elements to enhance the corrosion resistance.
AZ31B is often used as Magnesium Alloy Plate and Magnesium Alloy Rod, for magnesium plate, of which Hot Rolled Magnesium Alloy Plate and Casting Magnesium Alloy Plate are more common. As for magnesium rods, eExtruded Magnesium Alloy Rod are more common.
The following are the mechanical properties of AZ31B rolled magnesium alloy sheet with reference to GB/T 5154-2022 (Magnesium and magnesium alloys sheets and strips).
| Grade | State | Dimensions /mm | ||
| Thickness | Width | Length | ||
| AZ31B | H24 | >0.4-2 | ≤600 | ≤2000 |
| >2-8 | ≤1000 | ≤2000 | ||
| >8-32 | 400-1200 | 1000-3500 | ||
| >32-70 | 400-1200 | 1000-2000 | ||
| H26 | >6.3-50 | 400-1200 | 1000-2000 | |
| O | >0.4-1 | ≤600 | - | |
| >1-8 | ≤1000 | ≤2000 | ||
| >8-70 | 400-1200 | 1000-2000 | ||
| H112,F | >8-70 | 400-1200 | 1000-2000 | |
| Grade | State | Plate Thickness |
Tensile Strength (Rm)
MPa
|
Specified Non-Proportional Elongation Strength (Rp₀.₂)
MPa
|
Specified Plastic Compression Strength
(Rpe₀.₂)
MPa
|
Elongation at Break
％
|
|
| A | A₅₀ₘₘ | ||||||
| Not less than | |||||||
| AZ31B | O | 0.4-3 | 225 | 150 | - | 12 | |
| >3-12.5 | 225 | 140 | - | 12 | |||
| >12.5-70 | 225 | 140 | 10 | - | |||
| H24 | 0.4-8 | 270 | 200 | - | - | 6 | |
| >8-12.5 | 255 | 165 | - | 8 | |||
| >12.5-20 | 250 | 150 | 8 | ||||
| >20-70 | 235 | 125 | 8 | - | |||
| H26 | 6.3-10 | 270 | 186 | 6 | |||
| >10-12.5 | 265 | 180 | 6 | ||||
| >12.5-25 | 255 | 160 | - | 6 | - | ||
| >25-50 | 240 | 150 | 5 | - | |||
| H112 | 8-12.5 | 230 | 140 | 10 | |||
| >12.5-20 | 230 | 140 | 8 | - | |||
| >20-32 | 230 | 140 | 70 | 8 | - | ||
| >32-70 | 230 | 130 | 60 | 8 | - | ||
Mechanical properties of AZ31B extruded magnesium alloy rods reference GB/T 5155-2012 (Magnesium and magnesium alloy extruded rods).
Room temperature longitudinal mechanical properties of bars
| Grand | State | Bar diameter (square bar, hexagonal bar inner cut circle diameter)/mm |
Tensile strength
Rₘ/MPa
|
Specified non-proportional elongation strength
Rₚ₀.₂/MPa
|
Elongation at break
A/％
|
| Not less than | |||||
| AZ31B | H112 | ≤130 | 220 | 140 | 7 |
In addition, AZ31B can also be made into magnesium alloy forgings, its mechanical properties refer to GB/T 26637-2011 (Magnesium-alloy forgings)
| Grand | State | Rₘ (not less than) | Rᵃₚ₀.₂ (not less than) | Elongation/% (not less) δ₄ |
||
| MPa | (kis) | MPa | (kis) | |||
| AZ31B | F | 234 | (34) | 131 | (19) | 6 |
Processing properties
- Forming process: suitable for hot processing (e.g. extrusion, rolling, forging), cold processing requires caution to prevent cracking.
- Weldability: TIG/MIG welding is available, inert gas (e.g. argon) protection is required to prevent oxidation.
- Machinability: easy to cut, but magnesium chips are flammable, need to use coolant and control the temperature.
Corrosion resistance
- Weaknesses: susceptible to corrosion in humid, salty or acidic environments.
- Protection: Surface treatments such as anodizing, chemical conversion coatings (e.g., chrome-free processes), plating or painting.
Fields of application
- Transportation: automotive components (steering wheel skeletons, transmission housings), aerospace structural components.
- Electronics: laptop housings, camera bodies.
- Industrial equipment: lightweight tools, machine components.
Advantages and disadvantages
- Advantages: lightweight, high specific strength, good vibration damping, easy processing.
- Disadvantages: poor corrosion resistance, loss of strength at high temperatures, flammable (requires fire protection).
- Recyclability: 100% recyclable, in line with sustainable manufacturing trends.
- Cost: Moderately priced, subject to magnesium market fluctuations.