AluminiumAL
| Atomic number | Atomic Weight | |
|---|---|---|
| 13 | Aw=26.98g.mol-1 | |
| Dissolution Valence | n=3 | |
| Specific Charge Qspec | 10729 C.g-1 | |
| Specific Mass Removal Mspec | 0.0932 mg.C-1 | |
| Electrochemical Machinability Coefficient Kv | 0.0345 mm3.C-1 | |
| Density | Electrical Resistivity | Electrical Conductivity |
| ρ=2.70 | ρ=2.66 | s=37.6x10 |
Aluminium is a ductile, soft and light weight silvery white or dull grey metal. The metal is strongly corrosion resistant due to the thin layer of oxide that forms on the surface when the metal is exposed to air. Despite of that oxide layer on the surface, the pure metal aluminium can be electrochemical machined well, but because the metal is very good machinable with conventional methods ECM is only recommended when difficult shapes that can’t be machined otherwise are required. An other disadvantage of electrochemically machining aluminium is that the current efficiency will be high for all current densities (potentials), which means that the copying accuracy will be low. Under electrochemical machining conditions aluminium will dissolve as trivalent Al3+, which will react in the electrolyte to aluminiumhydroxide (Al(OH)3) or oxide (Al2O3). The aluminium(hydr)oxide can be removed from the electrolyte, for example by filtering.