Aluminium PM Process

1. Materials
GKN offer aluminium materials in a variety of chemistries to provide a wide range of properties that match the demanding needs of the marketplace. Materials include 2014, 6061, 7075, Al-14Si, and Al MMC (Aluminium Metal Matrix Composite) as well as several developmental materials to help meet our growing customer needs. Material development is a key differentiator and GKN has focused on delivering unique aluminium compositions for our customers.

 
2. Pressing / Compacting
GKN’s focused Aluminum facility has a variety of special presses with multi-level technology to produce products in the density range of 2.45 to 2.65 g/cm3 (88 - 95% of theoretical density). Aluminium powder is softer than iron based powder materials which allows for compaction at low pressures resulting in less wear and exceptional tooling life.

 
3. Sintering
Sintering is conducted in specially designed continuous furnaces with excellent temperature control which includes delubrication, sintering, and gas quench sections. Sintering temperatures are relatively low (typically at about 600 °C) and the atmosphere is 100% high purity nitrogen. Each furnace is capable of producing millions of parts annually.

 
4. Homogenization/Solutionizing (optional
Solutionizing is a heat treatment conducted just below the liquidus to homogenize the material. The parts become more ductile after this operation which enhances their response to subsequent sizing processes where density and strength are enhanced.

 
5. Sizing
Sizing/coining operations are employed as needed to densify and meet dimensional targets and tolerances, typically to the extent that no machining is necessary. Sizing of some materials increases the density which enhances the mechanical properties of the part.

 
6. Deburring/Tumbling
Is used to removed sharpe edges created during sizing and to provide a uniform surface appearance, while cleaning the part of sizing fluid.

 
7. Artificial Aging (optional
If the parts undergo solutionizing, they are subsequently heated to low temperature for a 24 hour period to artificially age the material and quickly build hardness and strength. This would normally take months if the parts were left to age at room temperature.

 
8. Secondary Operations
Secondary operations can include machining if dimensional requirements cannot be met with sizing. These also include impregnation, anodizing, alodine, or other surface treatments.