Mg与Ag含量对Al-Cu-Mg-Ag新型耐热铝合金晶间腐蚀性能的影响  

Effects of Mg and Ag Contents on Intergranular Corrosion Property of Al-Cu-Mg-Ag New Heat-resistant Al Alloy

作　　者：刘晓艳[1] 王召朋 龙亮[1] 张喜亮[1] 崔好选[1] 高飞[1] 

机构地区：[1]河北工程大学装备制造学院,河北邯郸056038

出　　处：《材料工程》2016年第9期68-75,共8页Journal of Materials Engineering

基　　金：河北省自然科学基金资助项目(E2013402056);河北省高等学校科学技术研究项目(QN2014002);河北省研究生创新资助项目(16129026)

摘　　要：采用晶间腐蚀性能测试研究Mg与Ag含量对Al-Cu-Mg-Ag合金抗腐蚀性能的影响,结合透射电子显微分析技术与电化学分析技术等探讨了不同成分合金的晶间腐蚀机理。结果表明:增加Mg与Ag含量能够提高合金的时效硬化速率。随Mg含量的增加,强化相Ω相尺寸逐渐减小,体积分数逐渐增大,晶界析出相增多,无沉淀析出带(PFZ)中溶质原子减少,PFZ与基体的电位差增大,合金的抗晶间腐蚀能力逐渐降低。随Ag含量的增加,合金中的强化相由大量的θ′相和少量的Ω相,逐渐转变为大量的Ω相和少量的θ′相。Ag含量的改变对PFZ的电位差影响不大,合金的耐蚀性主要取决于PFZ的宽度。增加Ag含量能够细化晶界析出相,减小PFZ宽度,腐蚀通道变窄,合金的抗晶间腐蚀性能得到提高。The effects of Mg and Ag contents on the corrosion resistance of Al-Cu-Mg-Ag alloy were investigated by intergranular corrosion（IGC）testing.The corrosion mechanism of the alloys with different chemical composition was discussed by transmission electron microscopy（TEM）and electrochemical analyses.The results indicate with increasing Mg and Ag content,the age hardening rate of the alloy increases.The size of the strengthening phasesΩ decreases with increasing Mg content whereas phase volume fraction increases.More solution atoms are consumed to form the precipitation on the grain boundaries of the alloy with higher Mg content,which increases the potential difference between precipitation free zone（PFZ）and the matrix and subsequently,the IGC resistance of Al-CuMg-Ag alloy decreases.Increasing the Ag content,the main strengthening phases transform from great amounts ofθ′with lessΩto plentifulΩwith lessθ′.The variation of Ag content hardly affects the potential of PFZ,and the corrosion resistance of the alloy depends mainly on the width of PFZ.With increasing Ag content,the precipitations on the grain boundaries are refined;the width of PFZ decreases and correspondingly,the corrosion passageway becomes narrow.The IGC resistance of AlCu-Mg-Ag alloy is enhanced with increasing Ag content.

关 键 词：Mg含量 Ag含量 AL-CU-MG-AG 晶间腐蚀 无沉淀析出带 

分 类 号：TG174.3[金属学及工艺—金属表面处理]