Studies of the Conversion Coatings Formed by Combined Use of Lanthanum Salt and Benzotriazole on Commercial Brass
Conversion coatings on commercial brass were prepared with lanthanum salt (La(NO3)3) and benzotriazole (BTAH) as reagents. A “Critical La(NO3)3 content” and “Critical BTAH content” were both observed, at which the coatings prepared performs the highest protectiveness.The results showed that La(NO3)3 and BTAH had an excellent synergism effect on the corrosion inhibition of brass. A remarkable enhancement of the brass’s corrosion protection was obtained by the formation of conversion coatings consisted of Cu2O, La2O3, Cu(I)BTA and La-complex, which acted as a barrier avoiding the release of metal ions and inhibited the diffusion of the oxygen.
Zhong Cao, Xueqiang Cao, Lixian Sun, Yinghe He
H. Q. Fan et al., "Studies of the Conversion Coatings Formed by Combined Use of Lanthanum Salt and Benzotriazole on Commercial Brass", Advanced Materials Research, Vols. 239-242, pp. 214-218, 2011