Aluminum anodes are rapidly replacing zinc anodes for cathodic protection of ship hulls. With the advent of alloys recently developed by the U.S. Navy, aluminum anodes are very different from those used for hull, outboard and stern drives. These aluminum anodes have better electrical activity and protection than zinc, plus they last longer, and for many years aluminum has been used in Marine engineering to protect equipment that requires long-term corrosion protection.
Aluminum anodes are rapidly replacing zinc anodes for cathodic protection of ship hulls. With the advent of alloys recently developed by the U.S. Navy, aluminum anodes are very different from those used for hull, outboard and stern drives. These aluminum anodes have better electrical activity and protection than zinc, plus they last longer, and for many years aluminum has been used in Marine engineering to protect equipment that requires long-term corrosion protection.
| Types | Zn | In | Cd | Sn | Mg | Si | Ti | Impurities, not more than | Al | ||
| Si | Fe | Cu | |||||||||
| Al-Zn-In-Cd | 2.5-4.5 | 0.018-0.050 | 0.005-0.02 | — | — | — | — | 0.1 | 0.15 | 0.01 | Balance |
| Al-Zn-In-Sn | 2.2-5.2 | 0.020-0.045 | — | 0.018-0.035 | — | — | — | 0.1 | 0.15 | 0.01 | Balance |
| Al-Zn-In-Si | 5.5-7.0 | 0.025-0.035 | — | — | — | 0.10-0.15 | — | 0.1 | 0.15 | 0.01 | Balance |
| Al-Zn-In-Sn-Mg | 2.5-4.0 | 0.020-0.050 | — | 0.025-0.075 | 0.50-1.00 | — | — | 0.1 | 0.15 | 0.01 | Balance |
| Al-Zn-In-Mg-Ti | 4.0-7.0 | 0.020-0.050 | — | — | 0.50-1.50 | — | 0.01-0.08 | 0.1 | 0.15 | 0.01 | Balance |
| Performance, types, indicators | Open circuit potential -V(SCE) | Working potential -V(SCE) | Actual capacitance A · h/kg | Current efficiency % | condition |
| Ordinary aluminum alloy anode | 1.10-1.18 | 1.05-1.12 | ≥2400 | ≥85 | Corrosion products are easy to fall off and dissolve evenly on the surface. |
| High-efficiency aluminum alloy anode | 1.10-1.18 | 1.05-1.12 | ≥2600 | ≥90 | |
| Highly activated aluminum alloy anode | 1.45-1.50 | 1.40-1.45 | ≥2080 | ≥70 |
