固溶温度对2A96铝锂合金电化学腐蚀性能的影响

为了寻求合适的固溶处理制度,采用电化学测试、金相组织观察、显微硬度测试等手段研究2A96铝锂合金的极化曲线、交流阻抗、开路电位与腐蚀时间的关系及其金相组织和显微硬度。在T6态下,选取5个不同固溶温度处理2A96铝锂合金,固溶处理时间均为60 min。实验结果表明:固溶温度为510 ℃时,合金的自腐蚀电压最小,自腐蚀电流密度最大,即固溶温度为510 ℃时试样最容易被腐蚀,腐蚀速率也最快,此时开路电位随腐蚀时间的增加下降最快;2A96铝锂合金在不同固溶温度下的金相组织晶粒尺寸都比较均匀,晶粒呈等轴状分布;固溶温度为540 ℃时,试样硬度最大,达到236.41 HV。

Effects of Solution Temperature on Electrochemical Corrosion Behavior of 2A96 Al-Li Alloy

In order to find a suitable solution treatment,the polarization curve,AC impedance,open circuit potential and corrosion time of 2A96 Al-Li alloy were studied by means of electrochemical method,microstructure and microhardness.In T6 state,2A96 Al-Li alloy was treated at 5 different solution temperatures for 60min.The experimental results showed that the corrosion voltage of the alloy was the minimum with the corrosion current density being the greatest when the solution temperature was 510℃,indicating the alloy was most vulnerable to corrosion,while the corrosion rate was the fastest at 510 ℃,and the open circuit potential decreased most rapidly with the increase of corrosion time.The grain size and microstructure of 2A96 Al-Li alloy were uniform at different solution temperatures,with the grain distribution being equiaxial.The hardness of the alloy reached 236.41 HV when the solution temperature was 540 ℃.