鋅–鋁合金熔射之耐蝕性評估

The Anti-Corrosion Performance of Zn-Al Thermal Sprayed Coatings

鋅及鋁應用於鋼構物之防蝕已行之有年，鋁的優越防蝕性來自於其表面緻密的氧化膜，而鋅具有較高之電化學活性，使鋅形成犧牲陽極以保護底材。鋅－鋁熔射皮膜之防蝕機理與鋅相近，均為形成犧牲陽極以保護底材。本研究即在探討鋅－鋁熔射之防蝕特性，並與鋁熔射、鋅熔射作一比較。由鹽霧實驗及電化學測試結果顯示，鋅－鋁熔射皮膜之腐蝕速率較慢，腐蝕曲線亦較為平緩，其防蝕性能優於鋅熔射皮膜，但較鋁熔射皮膜稍差。

Metal spraying has been utilized for the deposition of Zinc and Aluminum coatings for the corrosion protection of Steel. Aluminum coatings have the advantage of passive film formation. Zinc coatings have the advantage of electrochemical activity which enables them to provide excellent cathodic protection to Steel. The anti-corrosion mechanism of Zinc-Aluminum coatings are similar to Zinc sprayed. This paper evaluated the corrosion protective performance of Zinc-Aluminum coatings by salt spray (fog) accelerative and electrochemical test. The experimental results indicated that the corrosion rate and polarization curve of Zinc-Aluminum coatings are more slow than Zinc. The Zinc-Aluminum coatings exhibited combining the long-term protection of Aluminum and the cathodic protection performance of Zinc.