CAJ | 학술논문

对固溶态1441Al-Li合金板材分别进行T6时效，以及5%冷轧预变形后再进行150℃时效，即T8时效处理，通过晶间腐蚀(IGC)、剥落腐蚀(EXCO)实验、极化曲线测试及透射电镜(TEM)分析，研究时效制度对1441铝锂合金的室温抗晶间腐蚀性能、抗剥落腐蚀性能及微观组织的影响。结果表明，合金经T6或T8时效处理后，随时效时间延长，合金微观组织由欠时效的晶内析出均匀的δ′相，变为晶内析出δ′相和S′相，以及沿晶界析出平衡相δ相和S相，因此合金抗腐蚀性能顺序为欠时效＞峰时效＞过时效。与T6时效态相比，经T8时效处理后，晶内析出的δ′相和S′相的数量增加、尺寸减小、分布均匀；同时，沿晶界析出的δ相和S相数量减少，PFZ变窄，合金的抗晶间腐蚀和抗剥落腐蚀能力提高。在3.5%NaCl溶液中进行的极化曲线测试表现出相同的结果。
대고용태1441Al-Li합금판재분별진행T6시효，이급5%랭알예변형후재진행150℃시효，즉T8시효처리，통과정간부식(IGC)、박락부식(EXCO)실험、겁화곡선측시급투사전경(TEM)분석，연구시효제도대1441려리합금적실온항정간부식성능、항박락부식성능급미관조직적영향。결과표명，합금경T6혹T8시효처리후，수시효시간연장，합금미관조직유흠시효적정내석출균균적δ′상，변위정내석출δ′상화S′상，이급연정계석출평형상δ상화S상，인차합금항부식성능순서위흠시효＞봉시효＞과시효。여T6시효태상비，경T8시효처리후，정내석출적δ′상화S′상적수량증가、척촌감소、분포균균；동시，연정계석출적δ상화S상수량감소，PFZ변착，합금적항정간부식화항박락부식능력제고。재3.5%NaCl용액중진행적겁화곡선측시표현출상동적결과。
1441Al-Li alloy solid solution was aged at 150℃(T8) after T6 aging and 5%cold rolling pre-transformation. The effect of aging condition on intergranular corrosion resistance, exfoliation corrosion resistance and microstructure of 1441 aluminum alloy was investigated by means of intergranular corrosion experiments, exfoliation corrosion experiments, polarization curves measurement and transmission electron microscopy (TEM) analysis. The results show that, with increasing aging time, the uniform precipitation phase ofδ′within the alloy grains in the condition of under aging transforms to the precipitation phases ofδ′and S′within the grains, as well asδand S equilibrium phases along the grain boundaries. The order of corrosion resistance is as:under aging>peak aging>over aging. Compared with T6 aging, after T8 aging, the volumes ofδ′and S′phases increase, the size of the phases decreases and distributes uniformly, at the same time the volumes of δ and S phases decrease and PFZ minimizes at grain boundaries, which can increase the susceptibility to intergranular corrosion and exfoliation corrosion. The test of polarization curves in the 3.5%NaCl solution reveals the same conclusion.