Alloy Ak7ch (АЛ9)
Designation
| Name |
The value |
| Designation GOST Cyrillic |
АК7ч |
| Designation GOST Latin |
AK7ch |
| Transliteration |
AK7ch |
| The chemical elements |
- |
| Name |
The value |
| Designation GOST Cyrillic |
АЛ9 |
| Designation GOST Latin |
AL9 |
| Transliteration |
AL9 |
| The chemical elements |
- |
Description
Alloy Ak7ch used: for the manufacture of various ingots and shaped castings by various casting methods (sand casting, investment casting, gravity die casting, pressure); casting of parts of metallurgical engineering (parts of devices, housings of pumps, carburetors, operating at temperatures above +200 °C; sredneshirotnykh thin-walled and welded parts; casting parts of valves and actuators; castings of high-and medium-load and high integrity in all ways, except for the molding.
Note
Aluminum foundry alloy of the system Al-Si-Mg. The alloy has high integrity. Alloy is a substitute of alloys AL2 and AL7.
Advantages: Good corrosion resistance, mechanical properties and casting technology properties. Satisfactory machinability.
Disadvantages: the mechanical strength is inferior to alloy grade АЛ4.
Heat-treatable alloy with good strength properties. For corrosion resistance and technological characteristics of the alloy close to alloy grade AK12.
Standards
| Name |
Code |
Standards |
| Non-ferrous metals, including rare metals, and their alloys |
В51 |
GOST 1583-93, OST 4.021.009-92, OST 4.021.010-92, STP М287-78 |
| Castings from non-ferrous metals and alloys |
В84 |
OST 26-07-1114-74, OST 1 80029-83, OST 24.916.01-71, OST 5.9397-90 |
Chemical composition
| Standard |
Mn |
Si |
Fe |
Cu |
Al |
Ti |
Zn |
Sn |
Pb |
Mg |
Be |
| GOST 1583-93 |
≤0.5 |
6-8 |
≤0.6 |
≤0.2 |
The rest |
- |
≤0.3 |
≤0.01 |
≤0.05 |
0.2-0.4 |
≤0.1 |
| OST 24.916.01-71 |
≤0.5 |
6-8 |
≤0.6 |
≤0.2 |
The rest |
≤0.15 |
≤0.3 |
≤0.01 |
≤0.05 |
0.2-0.4 |
≤0.1 |
Al is the base.
According to GOST 1583-93, the total content of titanium and zirconium should be ≤ 015%; The iron content is indicated for sand casting and for investment models. The content of iron during casting in the mold is ≤ 1.00%, when casting under pressure ≤ 1.50%. The amount of allowable impurities should be for casting in sand molds and for investment models ≤ 1.10%, casting in chill molds ≤ 1.50%, injection molding ≤ 2.00%.
According to OST 24.916.01-71, the iron content is specified for casting in sand molds and for investment models. The content of iron during casting in the mold is ≤ 1.00%, when casting under pressure ≤ 1.50%. The amount of allowable impurities should be for sand casting and for investment models ≤ 1.60%, die casting ≤ 1.20%, die casting ≤ 2.10%.
By STP M287-78, the total content of titanium and zirconium should not be more than 0.15%. The amount of allowable impurities should be for casting in sand molds ≤ 1.10%, casting in chill mold ≤ 1.50%. The iron content is indicated for sand casting. The content of iron during casting in chill molds is ≤ 1.00%
Mechanical characteristics
| σB, MPa |
d |
Brinell hardness number, MPa |
| Casting (sand casting, investment casting, gravity die casting). Without heat treatment |
| ≥157 |
≥2 |
≥50 |
| Casting (sand casting, investment casting, gravity die casting, pressure). Mode T2: Annealing at 290-310 °C (2-4 h exposure) |
| ≥137 |
≥2 |
≥45 |
| Casting, including alloy, modified (m). Mode T4: Quenching in water from 530-540 °C (2-6 h exposure) |
| ≥176 |
≥4 |
≥50 |
| ≥186 |
≥4 |
≥50 |
| Casting, including alloy, modified (m). Mode T5: Quenching in water from 530-540 °C (extract 2-6 h) + Artificial aging at 145-155 °C (delay of 1-3 h) or two-stage heating: 180-200 °C (exposure 0.5 h) + 145-155 (exposure 2 hours) |
| ≥196 |
≥2 |
≥60 |
| ≥206 |
≥2 |
≥60 |
| Casting, including alloy, modified (m). T6 mode: Quenching in water from 530-540 °C (extract 2-6 h) + Complete artificial aging at 195-205 °C (extract 2-5 PM) |
| ≥225 |
≥1 |
≥70 |
| ≥235 |
≥1 |
≥70 |
| Casting, including alloy, modified (m). Mode T7: Quenching in water from 530-540 °C (extract 2-6 h) + stabilizing vacation at 215-235 °C (aging for 3-5 hours) |
| ≥196 |
≥2 |
≥60 |
| Casting, including alloy, modified (m). Mode T8: Quenching in water from 530-540 °C (extract 2-6 h) + soothing vacation at 240-260 °C (aging for 3-5 hours) |
| ≥157 |
≥3 |
≥55 |
Description mechanical marks
| Name |
Description |
| σB |
Limit short-term strength |
| d |
Elongation after rupture |
Physical characteristics
| Temperature |
Е, ГПа |
r, кг/м3 |
R, НОм · м |
| 20 |
70 |
2660 |
457 |
A description of the physical symbols
| Name |
Description |
| l |
Coefficient of thermal conductivity |
| С |
Specific heat |
Technological properties
| Name |
The value |
| Weldability |
Alloy welded satisfactorily. |
| Corrosion resistance |
To improve the corrosion resistance of the casting is subjected to anodic oxidation. |
| Machining by cutting |
The alloy is well processed by cutting and grinding. |
