基于DCB试样的7050铝合金应力腐蚀开裂敏感性研究

A Study on the Susceptibility to SCC of 7050 Aluminum Alloy by DCB Specimens.

作者信息

Qi Xing, Jin Jirong, Dai Chunli, Qi Wenjuan, He Wangzhao, Song Renguo

机构信息

Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164, China.

Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, China.

出版信息

Materials (Basel). 2016 Nov 1;9(11):884. doi: 10.3390/ma9110884.

DOI:10.3390/ma9110884

PMID:28774004

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5457230/

Abstract

The stress corrosion cracking (SCC) of different aging states for 7050 aluminum alloy in 3.5% sodium chloride aqueous solution has been studied by means of double cantilever beam (DCB) specimens, cathodic polarization, scanning electron microscope (SEM), transmission electron microscope (TEM) and time-of-flying second ion mass spectrometer (ToF-SIMS). The results showed that the susceptibility to SCC (Iscc) of 7050 aluminum alloy decreases with increasing the aging time. When a cathodic polarization potential of -1100 mV was applied to DCB specimens, the ion current intensity of hydrogen (I⁺) near the crack tip and Iscc increased obviously, thus the degree of the diffusion of hydrogen into the grain boundary become more serious. The observation of microstructure indicated that the precipitates on the grain boundary become coarse and are sparsely distributed with increasing the aging time of 7050 aluminum alloy.

摘要

采用双悬臂梁（DCB）试样、阴极极化、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和飞行时间二次离子质谱仪（ToF-SIMS），研究了7050铝合金在不同时效状态下在3.5%氯化钠水溶液中的应力腐蚀开裂（SCC）行为。结果表明，7050铝合金的应力腐蚀开裂敏感性（Iscc）随时效时间的增加而降低。当对DCB试样施加-1100 mV的阴极极化电位时，裂纹尖端附近的氢离子电流强度（I⁺）和Iscc明显增加，氢向晶界扩散的程度变得更加严重。微观结构观察表明，随着7050铝合金时效时间的增加，晶界上的析出相变得粗大且分布稀疏。