Alloy ML12
Designation
| Name |
The value |
| Designation GOST Cyrillic |
МЛ12 |
| Designation GOST Latin |
ML12 |
| Transliteration |
ML12 |
| The chemical elements |
CuЛ12 |
Description
Alloy ML12 applies: for production of castings loaded parts with maximum operating temperature of +200 °C - long, +250 °C short - term (beads, drums, wheels and other structures).
Note
Alloy system Mg-Zn-Zr.
Doping with zirconium refines the grain, reduces the temperature interval of crystallization and, therefore, improves mechanical and casting properties.
Compared with the alloys of the system Mg-Al-Zn alloy has several advantages. It possess higher strength characteristics. Refinement of the structure with the introduction of Zirconia reduces the sensitivity of the alloy to the thickness of the cross section of the casting. Due to the smaller grain size in castings microregion less than in the casting of alloys МЛ4 or ML5.
ML12 alloy has satisfactory casting properties that allows its use for the casting of large castings of complex configuration in sand casting and gravity die casting. High yield strength alloy more ductile than the alloys of ML5 and МЛ6. It can be used in conditions of high static and alternating loads.
Disadvantages of alloy - poor weldability and a tendency to form hot cracks during casting of thin-walled castings.
Standards
| Name |
Code |
Standards |
| Non-ferrous metals, including rare metals, and their alloys |
В51 |
GOST 2856-79 |
| Thermal and thermochemical treatment of metals |
В04 |
OST 1 90121-90 |
| Castings from non-ferrous metals and alloys |
В84 |
OST 1 90200-75, OST 1 90248-77 |
| Test methods. Packaging. Marking |
В59 |
OST 1 90360-85 |
Chemical composition
| Standard |
Si |
Ni |
Fe |
Cu |
Al |
Zn |
Zr |
Mg |
Be |
| GOST 2856-79 |
≤0.03 |
≤0.005 |
≤0.01 |
≤0.03 |
≤0.02 |
4-5 |
0.6-1.1 |
The rest |
≤0.001 |
Mg is the basis.
According to GOST 2856-79, the content of other impurities is ≤ 0.12%, the sum of the impurities being determined is 0.20%.
Mechanical characteristics
| Section, mm |
sT|s0,2, MPa |
σB, MPa |
d5, % |
| Casting in sand, shell, investment casting and plaster mold and chill casting GOST 2856-79. Without heat treatment |
|
≥90 |
≥200 |
≥6 |
| Casting in sand, shell, investment casting and plaster mold and chill casting GOST 2856-79. Mode T1: Aging |
|
≥130 |
≥230 |
≥5 |
| Casting forming OST 1 90200-75. In the delivery condition specified in the casting method, delivery condition and strength class KP |
|
≥147 |
≥245 |
≥6 |
|
≥137 |
≥226 |
≥5 |
|
≥128 |
≥206 |
≥4 |
|
≥128 |
≥186 |
≥3 |
Description mechanical marks
| Name |
Description |
| Section |
Section |
| sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
| σB |
Limit short-term strength |
| d5 |
Elongation after rupture |
Physical characteristics
| Temperature |
Е, ГПа |
r, кг/м3 |
l, Вт/(м · °С) |
С, Дж/(кг · °С) |
| 20 |
43 |
1810 |
1339 |
9629 |
A description of the physical symbols
| Name |
Description |
| Е |
The normal elasticity modulus |
| r |
Density |
| l |
Coefficient of thermal conductivity |
| R |
UD. the resistivity |
Technological properties
| Name |
The value |
| Features of heat treatment |
According to OST 1 90121-90 casting in the ground, shell molding, gravity die casting, investment casting and plaster mold to enhance mechanical properties of castings (σв, σ0,2) applied heat treatment regime T1 - Aging at 300±5 °With (extract 4-6 hours), air cooling. |
