Alloy ML9
Designation
| Name |
The value |
| Designation GOST Cyrillic |
МЛ9 |
| Designation GOST Latin |
ML9 |
| Transliteration |
ML9 |
| The chemical elements |
CuЛ9 |
Description
Alloy ML9 used: for the manufacture of shaped castings of parts with maximum operating temperature of 250−300 °C for a long time, +350−400 °C — short-term.
Note
High-temperature alloy system MD-REE-Zr. For alloying of the alloy of the rare earth metals neodymium use. The alloy contains additives of indium and zirconium.
Alloy combines sufficiently good mechanical properties at room temperature with high heat resistance, good casting and technological properties, allowing to obtain a dense casting with a uniform mechanical properties in the cross-sections of different thickness.
Alloy ML9 is also used for parts of engines and instruments, but its heat resistance is lower than that of alloy ML19.
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 |
Chemical composition
| Standard |
Si |
Ni |
Fe |
Cu |
Al |
Zn |
Zr |
Nd |
Mg |
Be |
In |
| GOST 2856-79 |
≤0.03 |
≤0.005 |
≤0.01 |
≤0.03 |
≤0.02 |
≤0.15 |
0.4-1 |
1.9-2.6 |
The rest |
≤0.001 |
0.2-0.8 |
Mg is the basis.
According to GOST 2856-79, the content of other impurities is ≤ 0.10%, the sum of the impurities to be determined is 0.35%.
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. T6 mode: Homogenization + annealing at air + aging |
|
≥110 |
≥230 |
≥4 |
| Casting forming OST 1 90200-75. In the delivery condition specified in the casting method, delivery condition and strength class KP |
|
≥118 |
≥226 |
≥4.5 |
|
≥108 |
≥206 |
≥4 |
|
≥108 |
≥191 |
≥3.5 |
|
≥108 |
≥177 |
≥2.5 |
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) |
| 20 |
43 |
1760 |
1172 |
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 to improve the mechanical properties (σв, σ0,2) casting in the ground, shell molding, gravity die casting, investment casting and plaster mold apply heat treatment by mode T6 - Tempering by blowing air 540±5 °C (exposure 8-12 h) + Aging at 200±5 °C (exposure 6-12 h), air cooling. In this case the plastic properties decrease. A noticeable increase in the values of σв, σ0,2 is achieved in the hardening of the casting by blowing air. |
