CAJ | 학술논문

采用扫描电镜、透射电镜、X射线衍射、电化学性能测试等方法,研究了Al-5Zn-0.02In-1Mg-0.05Ti牺牲阳极合金中析出相的腐蚀行为.结果表明,该合金主要含η-MgZ_2析出相.η析出相相对α-Al基体呈阳极相,在3.5%的NaCl溶液中与α-Al基体组成微腐蚀电池,引起析出相自身溶解.溶解的Zn~(2+)沉积在蚀坑周围,增加这些位置氧化膜的缺陷,促使氧化膜脱落.该牺牲阳极合金的溶解是以η析出相为活化中心,由此向外扩展,引发合金全面溶解.
채용소묘전경、투사전경、X사선연사、전화학성능측시등방법,연구료Al-5Zn-0.02In-1Mg-0.05Ti희생양겁합금중석출상적부식행위.결과표명,해합금주요함η-MgZ_2석출상.η석출상상대α-Al기체정양겁상,재3.5%적NaCl용액중여α-Al기체조성미부식전지,인기석출상자신용해.용해적Zn~(2+)침적재식갱주위,증가저사위치양화막적결함,촉사양화막탈락.해희생양겁합금적용해시이η석출상위활화중심,유차향외확전,인발합금전면용해.
Activation effects of η precipitates in the Al-5Zn-0. 02In-lMg-0. 05Ti sacrificial anode alloy were examined by SEM (scanning electron microscope), TEM (transmission electron microscope) , XRD(X-ray diffraction) and electrochemical properties testing. The results reveal that the main precipitates are the MgZn_2 phase (η phase). The η precipitates are taken as anodic phase to form a micro-corrosion cell with or Al matrix in 3.5%NaCl solution, leading to the self-dissolution of the precipitates. Dissolved Zn~(2+) is deposited around the pit to enhance the occurrence of oxidized defects and to promote the exfoliation of oxidization film. The ηphases are acted as the activation center for alloy dissolution, resulting in the whole dissolution of the alloy by extending outward.