中文摘要：

通过调整杂质元素Si的含量研究了Si含量对7050铝合金组织和耐腐蚀性能的影响规律。结果表明，合金固溶时效后的组织沿加工方向排列。晶内弥散的第二相颗粒主要为A12CuMg相和Mg2Si相，形态为长条状或针状；第二相的含量、分布及形态等与Si元素的含量密切相关。同时，Si含量升高，电导率也升高；Si含量高的合金自腐蚀电位也有所提高。提高Si含量有利于延迟剥蚀的发生，但对之后的剥蚀有较强的加速作用。

英文摘要：

The effects of Si content on the microstructure and corrosion resistance of 7050A1 alloy were investigated. The results show that grains are arranged along the machining direction after aging treatment. The main second phases are A12CuMg and Mg2Si. The amount, distribution and shape of the second phases are closely related to the content of Si. The electrical conductivity and corrosion potential increase with the increase of Si content. The higher content of Si can delay the start of exfoliation corrosion, but can accelerate the process of exfoliation corrosion.