(1. 四川理工學(xué)院工程實踐中心，自貢 643000；
2. 四川理工學(xué)院機械工程學(xué)院，自貢 643000；
3. 四川大西洋焊接材料股份有限公司，自貢 643010；
4. 西南交通大學(xué)材料科學(xué)與工程學(xué)院，成都 610031)
摘 要: 利用金相顯微鏡分析7A04鋁合金半固態(tài)與鑄態(tài)組織，對半固態(tài)與鑄態(tài)7A04鋁合金進行極化曲線與阻抗譜電化學(xué)測試分析，通過中性鹽霧實驗對比分析二者的質(zhì)量損失率、腐蝕面積率和腐蝕坑深度，并采用激光共聚焦顯微鏡分析腐蝕形貌差異。結(jié)果表明：半固態(tài)初生α(Al)晶粒細(xì)小圓整，半固態(tài)試樣的耐腐蝕性能優(yōu)于鑄態(tài)試樣的，半固態(tài)試樣腐蝕質(zhì)量損失率較低，半固態(tài)試樣的蝕坑平均深度及最大深度均小于鑄態(tài)試樣的。半固態(tài)工藝可顯著提高7A04鋁合金的耐腐蝕性能。
關(guān)鍵字: 7A04鋁合金；半固態(tài)；鑄態(tài)；極化曲線；阻抗譜；鹽霧腐蝕
（1. Engineering Practice Center, Sichuan University of Science and Engineering, Zigong 643000;
2. College of Mechanical Engineering, Sichuan University of Science and Engineering, Zigong 643000;
3. Sichuan Atlantic Welding Consumables Co., Ltd., Zigong 643010;
4. School of Material Science and Engineering, Southwest Jiaotong University, Chengdu 610031）
Abstract:The microstructure of semi-solid and as-cast 7A04 aluminum alloys was studied by optical microscopy, and the electrochemical corrosion behavior was investigated mainly by polarization curve and impedance spectroscopy. The mass loss rate, corrosion area rate and corrosion depth were researched by the salt spray corrosion, the corrosion morphologies were observed by laser scanning confocal microscopy. The results show that the semi-solid processing leads to a structure with fine and round grains (primary α(Al)), corrosion resistance of semi-solid sample is better than that of the as-cast sample. Both mass-loss and average corrosion depth of semi-solid sample are smaller than those of the as-cast sample. The semi-solid processing can improve the corrosion resistance of 7A04 aluminum alloy obviously.
Key words: 7A04 aluminum alloy; semi-solid; as-cast; polarization curve; impedance spectroscopy; salt spray corrosion
