Zn及热处理制度对2056铝合金力学性能及局部腐蚀行为的影响  

Effects of Zn and aging condition on mechanical properties and local corrosion behavior of 2056 aluminum alloy

作　　者：罗先甫[1] 郑子樵[1] 葛婧萱[1] 张海锋[1] 钟警[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2012年第1期55-62,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：国家重点基础研究发展规划(973计划)资助项目(2005CB623705)

摘　　要：通过拉伸性能测试、晶间腐蚀(IGC)、剥落腐蚀(EXCO)实验、极化曲线测试及透射电镜(TEM)分析,研究Zn元素和不同热处理制度对2056铝合金室温常规力学性能、抗晶间腐蚀性能、抗剥落腐蚀性能及微观组织的影响。结果表明,微量Zn均匀存在于合金的各个位置,可促进S′相的析出和提高合金强度;减小晶内与晶界的电化学腐蚀动力,使晶界析出的S相数量减少并不连续分布,无沉淀析出带(PFZ)变窄,提高合金的抗晶间腐蚀性能和抗剥蚀性能。与T6处理态相比,经T8处理后,晶内析出的S′相数量增加、尺寸减小、分布均匀,合金的强度显著提高,塑性降低;同时,沿晶界析出的S相数量减少,PFZ变窄,合金的抗晶间腐蚀和抗剥落腐蚀能力提高。在3.5%的NaCl溶液中进行的极化曲线测试也表现出相同的结果。The effects of Zn and aging condition on mechanical properties,intergranular corrosion resistance,exfoliation corrosion resistance and microstructure of 2056 aluminum alloy were investigated by means of tensile testing,intergranular corrosion experiments,exfoliation corrosion experiments,polarization curves measurement and transmission electron microscopy（TEM） analysis.The results show that trace Zn distributes uniformly in the alloy and it can promote the precipitation of S′ phase which can improve the strength and decrease the electrochemistry corrosion kinetics.The precipitation of S equilibrium phases along the grain boundaries decreases and distributes discontinuously,and the precipitate free zone（PFZ） becomes narrower in the alloy containing Zn,which can enhance the exfoliation corrosion resistance and the intergranular corrosion resistance of the alloy.After T8 temper,the strength improves and the plasticity decreases,less S′ phase precipitates uniformly at the grain interface.The precipitation of S equilibrium phases along the grain boundaries decreases and the PFZ becomes much narrower,which can improve the intergranular corrosion resisitance and exfoliation corrosion resistance compared with T6 temper.The test of polarization curves in the 3.5% NaCl solution reveals the same conclusion.

关 键 词：ZN 热处理 2056铝合金 局部腐蚀 微观组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]