to Metals
to Aluminum alloys
Dr. Dmitri Kopeliovich
Aluminum alloys, possessing exceptional mechanical properties, are prepared by powder technology.
These alloys are called sintered alloys or Sintered Aluminum Powders (SAP).
Sintered aluminum alloys have the following advantages:
Unique properties of the sintered aluminum alloys are result of presence of aluminum oxide (Al2O3) in the alloy structure.
Film of aluminum oxide covers each aluminum powder particle.
The oxide film is not reduced in the sintering and it prevents movement of dislocationsthrough the aluminum grain boundaries, providing the outstanding mechanical properties of the alloys.
Some of sintered aluminum alloys besides aluminum oxide contain also aluminum carbide (Al4C3).
Concentration of aluminum oxide in the sintered aluminum alloys varies between 1 to 20%, depending on the thickness of the oxide film and on the powder particles sizes.
Aluminum sintered alloys are sintered at 1000-1200°F (540-650°C) for 10-20 minutes.
| Designation | Si,% | Cu,% | Mg,% | Lubrication,% | Aluminum with aluminum oxide,% |
|---|---|---|---|---|---|
| A | 0.6 | 0.25 | 1.0 | 1.5 | balance |
| B | 0.6 | 4.4 | 0.5 | 1.5 | balance |
| C | 0.4 | - | 0.6 | 1.5 | balance |
| D | - | 4.0 | - | 1.5 | balance |
| E | 0.3 | 2.0 | 1.0 | 1.5 | balance |
| F | - | 1.6 | 2.5 | 1.5 | balance |
| G | 0.75 | 3.8 | 1.0 | 1.5 | balance |
to Metals
to Aluminum alloys