Zn-Al合金流電陽極の皮膜抵抗と陽分極特性

抄録

Zinc and zinc alloys, prepared by adding 0.1-1.0% Al to various grades of zinc, were tested iunder laboratory condition. Specimens were mantained as anode with the constant current density of 1.0mA/cm² in artificial sea-water at room temperature for more than 1000hrs. Through the test, anodic potentials were measured, and finally film resistances and weight losses were determined.
Results obtained were as follows:
(1) The tendency to become passive of lower-purity zinc is ascribed to the film resistance on surface and the increased anodic polarization caused by the film.
(2) In the case of lower-purity zinc the addition of Al in the range of 0.2-0.7% extremely reduced the film resistance, even to the degree further less than those of special high-purity zinc such as 99.9996% zinc. When its addition exceeded this range the film resistance began to increase again.
(3) In the case of high-purity zinc, the optimum range of Al content moves rather to smaller value such as 0.1-0.2%.