Abstract:
The metal sprayed aluminum, when exposed to natural atmospheres, acts as noble coating due to passivation this is the reason why aluminum coated steels exhibit red tarnishing, after a relatively short period of time, as a consequence of the corrosion of the steel at coating porosities. This aesthetic underisable tarnishing has little influence on the durability of aluminum coated products, because the corrosion process is interrupted due to the rupture of the passivation layer of aluminum. When this occurs the aluminum begins to act as sacrificial coating. The corrosion of aluminum is further subdued because the pores of the coating are gradually tropped by the aluminum corrosion products. The objective of this study is to clarify the mechanisms involved in the behavior of metal sprayed aluminum coatings.
Reference:
KAJIMOTO, Z.P.; ALMEIDA, N.L.; SOUZA, E.F.M. Estudo do comportamento frente à corrosão atmosférica do revestimento de alumínio aplicado sobre o aço por aspersão térmica. In: INTERNATIONAL CONGRESS FOR SURFACE FINISHING. 1992, São Paulo. Proceedings… São Paulo: ABTS, 1992. v. 2, p. 1046-1068. (IPT Pub. 2115)
The metal sprayed aluminum, when exposed to natural atmospheres, acts as noble coating due to passivation this is the reason why aluminum coated steels exhibit red tarnishing, after a relatively short period of time, as a consequence of the corrosion of the steel at coating porosities. This aesthetic underisable tarnishing has little influence on the durability of aluminum coated products, because the corrosion process is interrupted due to the rupture of the passivation layer of aluminum. When this occurs the aluminum begins to act as sacrificial coating. The corrosion of aluminum is further subdued because the pores of the coating are gradually tropped by the aluminum corrosion products. The objective of this study is to clarify the mechanisms involved in the behavior of metal sprayed aluminum coatings.
Reference:
KAJIMOTO, Z.P.; ALMEIDA, N.L.; SOUZA, E.F.M. Estudo do comportamento frente à corrosão atmosférica do revestimento de alumínio aplicado sobre o aço por aspersão térmica. In: INTERNATIONAL CONGRESS FOR SURFACE FINISHING. 1992, São Paulo. Proceedings… São Paulo: ABTS, 1992. v. 2, p. 1046-1068. (IPT Pub. 2115)
