Jun Jiheon, Lim Yong Chae, Li Yuan, Warren Charles David, Feng Zhili
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
Materials (Basel). 2021 Mar 29;14(7):1670. doi: 10.3390/ma14071670.
The use of polymer insulation to mitigate galvanic corrosion was examined for bolted joints of AZ31B Mg alloy and carbon fiber-reinforced composite. To assess the corrosion behaviors of bolted joints with and without polymer insulation, solution immersion and salt spray exposure (ASTM B117) tests were conducted, and the corrosion depths and volumes were determined for the joint specimens after the tests. The polymer-insulated bolted joints exhibited much lower corrosion depths and volumes, highlighting the effective mitigation of galvanic corrosion. The reductions of joint strength in the post-corrosion joint specimens were relatively small (up to 10%) in the polymer-insulated group but greater (up to 90%) in the group with no insulation. Cross-sectional characterization of post-corrosion joints with polymer insulation revealed local pits developed on AZ31B under galvanic influence, indicating that limited galvanic attack (that did not decrease the joining integrity significantly) could still occur during a long salt spray exposure (1264 h) owing to the permeation of an aqueous corrosive medium.
研究了使用聚合物绝缘材料来减轻AZ31B镁合金与碳纤维增强复合材料螺栓连接的电偶腐蚀。为评估有无聚合物绝缘的螺栓连接的腐蚀行为，进行了溶液浸泡和盐雾暴露（ASTM B117）试验，并在试验后测定了接头试样的腐蚀深度和腐蚀体积。聚合物绝缘的螺栓连接显示出低得多的腐蚀深度和腐蚀体积，突出了电偶腐蚀的有效减轻。在腐蚀后接头试样中，聚合物绝缘组的接头强度降低相对较小（高达约10%），而无绝缘组的接头强度降低更大（高达90%）。对有聚合物绝缘的腐蚀后接头的横截面表征显示，在电偶作用下AZ31B上出现了局部凹坑，这表明由于腐蚀性水介质的渗透，在长时间盐雾暴露（约1264小时）期间仍可能发生有限的电偶侵蚀（但未显著降低连接完整性）。
