Papers by Author: Guang Xia Sun

Abstract: Silane coupling agent is gradually concerns as a substitute for phosphate pre-treatment of painting. Ten kinds of silane solution such as the KH-450, KH-460, KH-470, KH-550, KH-560, KH-567, KH-578, 5501, 9810, BTSE were chosen as research objects in this paper. Corrosion resistance and adhesion of film were studied after silane treatment on A3 steel surface by copper sulfate drop test, alternate immersion in salt solution and adhesion experiments. These silane films were compared with uncoated A3 steel specimens. The results show that: silane treatment can improve the corrosion resistance of A3 steel in acid solution. KH-560, KH-5501 and KH-470 were ranked the top three in the corrosion resistance. KH-550, KH-560, KH-567 were fourth, fifth and sixth, respectively. Silane treatment can improve the corrosion resistance of A3 steel in neutral salt solution. KH-460, KH-560 and KH-567 have the best salt water corrosion resistance. KH-560 has better adhesion with paint film, following by KH-550 and KH460. When using ethanol and water as the hydrolysis solvent of silane, KH-450, KH-460, KH-470, KH-550, KH-560, KH-567, KH-578, 5501 have the better stability, but stability of 9810, BTSE are poor.

Abstract: The silane films are fabricated by dipping cast aluminum alloy in silane solution, then curing films. The corrosion resistance of single silane film, composite silane film is compared with phosphating film through acid dropping test, salt water immersion test and electrochemical impedance test (EIS), the results shows that the silane films are obviously superior to the phosphating films in terms of the corrosion resistance of acid solution and neutral salt solution, particularly the corrosion resistance of composite silane films is much better than sigle silane films; corrosion polarization curves show that the corrosion tendency of KH550+KH567 composite silane film is minimum, corrosion rate is yet minimal, corrosion process of this silane films is controled by diffusion step. The corrosion process of uncoated aluminum substrate, KH550 silane films, phosphating films are controlled by electrochemical step. The impedance of phosphate films are lower than the silane films. Appropriate silane treatment can effectively improve adhesion between the coating and the Al substrate. The adhesion between silane film and paint film is firmer than the phosphate film, so silane film is an excellent replacement to phosphate film for painting pre-treatment.