Ura-Bińczyk Ewa
Faculty of Materials Science and Technology, Warsaw University of Technology, ul. Wołoska 141, 02-747 Warsaw, Poland.
Materials (Basel). 2022 Jan 4;15(1):360. doi: 10.3390/ma15010360.
The effect of aging on the resistance to pitting corrosion of ultrafine-grained 7475 aluminium (Al) alloy processed by hydrostatic extrusion (HE) is studied. Differences in the microstructure were investigated using secondary electron (SEM) and transmission electron microscopy (TEM). Corrosion tests were performed in 0.1 M NaCl, and characterization of corroded surface was performed. The results of this work show that the pitting susceptibility of ultra-fine grained 7475Al is related to the distribution of MgZn precipitates. After HE, the formation of An ultrafine-grained microstructure at the grain boundaries of ultrafine grains is observed, while subsequent aging results in the formation of MgZn precipitates in the grain interior. Grain refinement increases susceptibility to localized attack, while the subsequent aging improves the overall corrosion resistance and limits the propagation of corrosion attack.
研究了时效对经静水挤压（HE）加工的超细晶粒7475铝合金点蚀抗性的影响。使用二次电子（SEM）和透射电子显微镜（TEM）研究了微观结构的差异。在0.1M NaCl中进行了腐蚀试验，并对腐蚀表面进行了表征。这项工作的结果表明，超细晶粒7475Al的点蚀敏感性与MgZn析出相的分布有关。经HE处理后，在超细晶粒的晶界处观察到形成了超细晶粒微观结构，而随后的时效导致在晶粒内部形成MgZn析出相。晶粒细化增加了局部腐蚀的敏感性，而随后的时效提高了整体耐腐蚀性并限制了腐蚀侵蚀的扩展。
