Nano silicate와 Epoxy silane을 利用한 航空用 aluminum合金 材料 保護塗裝에 관한 硏究

Abstract

에폭시 실란과 나노 실리케이트를 적용하여 일반 에폭시 수지와의 방청성능을 비교하고 표면처리의 유, 무에 따라 여러 가지 가속 노화 실험을 하여 교류 임피던스 법으로 부식 노화 과정을 관찰 하였으며 SEM/EDAX, FT-IR을 적용하여 분석해본 결과로서 다음과 같은 결론을 얻었다. (1) 에폭시 실란 수지의 적용은 일반 에폭시 수지에 비해 표면 장력을 낮추어 수분의 침투를 억제하고 방식성능에 큰 영향을 준다. (2) 나노 실리케이트 안료의 함유로 부동태피막을 형성하고 소지를 보호하는데 적절한 기능을 하는 것을 한다. (3) 화성피막처리는 비철금속의 내식성에 영향을 끼치며 도료와의 방청성에도 영향을 준다. (4) 교류임피던스는 복합가속시험 방법과 여러 분석방법을 통해 도막의 노화 평가가 가능함을 확인할 수 있었다.

All components of an aerospace coatings system must be functioning properly for it to provide all of the elements of physical protection and optical performance that it was designed to provide. To ensure proper coatings system functions over its desired lifetime, one must have the capability to define, measure and evaluate those system properties that determine these functions in use. For aircraft, the desired properties can be summarized as mechanical/chemical protection of the airframe with controlled electromagnetic emission and reflection properties. The current “best practice” thinking among the coatings science community focuses on system flexibility, adhesion, solvent resistance, corrosion protection and camouflage optics as determined over the coatings lifetime while taking into account the effects of UV exposure, hot and cold organic fluids, sea water, humidity and temperature cycling, mechanical stressing and abrasion. All of these must be considered in choosing the tests/results protocol that the coatings/pre-treatment must undergo to be “"fit for use”. In the last few years great efforts have been made in order to find and to develop environmentally friendly substitutes for Cr^(6+) pre-treatments applied to aluminium alloys used in the aircraft industry. The silane performance is comparable to, or in some cases better than, that of chromate layers. The most recent studies also showed that the silane films can be thickened and strengthened by loading of a small amount of nano particles such as silica and alumina into the films resulting in enhanced corrosion protection of aluminum alloys. Epoxy silane layers modified with nano silicate applied to Al alloy 2024 substrates. The corrosion behaviour was investigated in 0.5 N NaCl solution electrochemical impedance spectroscopy (EIS). SEM/EDAX and FT-IR were used to evaluate information on the chemistry of the epoxy silane with nano silicate. The results have shown that the introduction of additives improves the corrosion protection properties of the epoxy silane layer.