51 The Resistens of Superficial Corrosion Layers Obtained Through Impulse Electrical Discharges Using Aluminium Electrodes

The experimental research was made on superficial layers laid-down through electrical sparking on the steel carbon OL 37 probes, the used electrode being made from a corrosion resistant material (Aluminum).

The experiments where for the superficial treatment through impulse electrical discharges, made with the ELITRON 22A equipment, using an Al electrode of some parallelepiped probes with the surfaces of 0,00127512 m2, from steel carbon OL 37 brand, the probes plane surfaces where previously prepared. Preparing the surfaces presumes a thorough treatment and degrease with a powerful solvent.

The treatment through electrical discharges where made manually, the active electrode is under a 60° angle with the treated surface. The probes on which the superficial treatment was made through impulse electrical discharges where individually weighted on the analytic balance at different time intervals, determining the corrosion process speed. The fine determining of the topography surfaces exposed to the action of the corrosive environment was made using the atomic force microscopy (AFM).

For a comparative analysis of the effect of the corrosive environment on the superficial treated probes and on the untreated ones, a series of determinations have targeted the analysis of the surfaces of a probe subjected to the corrosive action of the environment, in the same conditions as the superficial treated probes but without the protection of the surfaces of the probe.

The lack of the superficial layer permitted the corrosive environment a massive and pronounced attack on the probes material. The images on the original probe, resulted from the atomic force microscopy (AFM), indicate that after the action of the corrosive environment, shows unevenness, with material loss, which can be noted on the whole surface of the probe. In certain higher portions of the probes material, as a result of different phases from the structure, it was 1œconsumed1 less intense.