RE-PASSIVATION POTENTIAL OF ALUMINUM
RE-PASSIVATION POTENTIAL OF ALUMINUM AND ITS ALLOY BY GALVAN STATIC MEASUREMENT - ASTM D 6208
The Test equipment is in accordance with ASTM D 6208 in which an aluminium alloy is polarized at fixed current density for fixed time period in a solution of coolant & chloride solution. Upon polarization the maximum potential EB, or the break potential at which the passive aluminium oxide layer breaks down and subsequently minimum potential EG, or the protection potential at which oxide layer repassivates are recorded as the function of time intervals by Galvanostatic method. The software logs continuously the time and potential. These potential values are indications of the relative effectiveness of inhibitors to mitigate pitting corrosion of aluminium and its alloys. This method gives quick qualitative correlation of the measurements and susceptibility in service.
| Test cell | O-ring borosilicate glass joint, tie-rod & clamming arrangement, silicone gasket, etc. |
| Power supply | Constant current Power Supply (PSU) to regulate output current to 872 µA continuously. |
| Control panel | Variable heating control, digital temperature indicator cum controller, digital display. |
| Recording assembly record. | The recorder of high input impedance (>1012 ohms), continuous data logger with software determine: Log of time v/s potential relation, direct plotted graph to EB & EG. |
| Electrodes | Working UNS A93003 aluminium alloy, Auxiliary refined graphite, Reference Ag/AgCl. |
| Control panel | Potential indicator cum controller, precise controlling and recording. |
| Recommended spares | Personal computer, printer, electrodes, etc. |