时效过程对2519铝合金抗晶间腐蚀性能的影响  

Effect of Aging Process on the Intergranular Corrosion of 2519 Aluminium Alloy

作　　者：李慧中[1] 张新明[1] 陈明安[1] 周卓平[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《金属热处理》2005年第5期58-61,共4页Heat Treatment of Metals

基　　金：国家"973"重点基础研究发展规划项目(G1999064908)

摘　　要：用显微硬度计、光学金相显微镜、透射电镜等手段研究了2519铝合金在180℃下的时效特性及不同时效状态对合金的抗晶间腐蚀能力的影响。结果表明,2519铝合金在180℃时效时具有三阶段时效特性,达到峰值时效时间为12h。欠时效状态下合金有明显的晶间腐蚀,而峰值时效和过时效状态下晶间腐蚀不敏感。欠时效状态下,晶界析出相呈连续链状分布,晶界上无沉淀带较宽;而在峰值时效和过时效状态下,晶界析出相呈离散分布,无沉淀带较窄,晶间腐蚀是作为阳极的贫铜区发生腐蚀形成溶解通道所致。Isothermal age-hardening curve and effects of ageing time on intergranular corrosion of 2519 aluminium alloy aged at 180°C were investigated by means of optical microscopy and transmission electron microscopy. The results show that the three aged stages are observed in the 2519 aluminium alloy aged at 180°C, and its peak-aged time is 12 h. The under-aged alloy is sensitive to intergranular corrosion, while the peak-aged or the over-aged one is not. Continuous precipitate chains are found on the grain boundaries of the under-aged alloy and the precipitate-free zones on the grain boundaries are wide, while in the peak-aged or the over-aged alloy the precipitates distribute in a discrete manner and the precipitate-free zones on the grain boundaries become very narrow. The intergranular corrosion could be ascribed to anodic dissolution of the Cu-depleted zones.

关 键 词：2519铝合金 时效 晶间腐蚀 无沉淀带 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG174.3[金属学及工艺—金属材料]