热处理制度对2519铝合金晶间腐蚀性能的影响

Effect of Heat Treatment on Microstructure,Tensile Strength and Intergra nular Corrosion of 2519 Aluminum Alloy

通过拉伸测试、显微硬度测试、透射电镜 (TEM)及扫描电镜 (SEM)分析等手段研究了不同热处理制度对 2 5 19铝合金组织、力学性能及抗晶间腐蚀性能的影响。结果表明 ,与T6状态相比 ,2 5 19合金经T8处理后 ,合金的强度、硬度提高 ,合金峰值时效时间提前 ,但塑性降低 ,同时 ,晶内沉淀析出的θ′相数目增加、尺寸减小、分布均匀 ,沿晶界析出的θ′(θ)相数量减少 ,且不连续分布 ,无沉淀带变窄。T8处理提高了合金峰值时效态抗晶间腐蚀的能力。

The effect of heat treatment on the microstructure, tensile strength and intergranular corrosion of 2519 aluminum alloy was investigated by means of tensile test, microhardness test, transmission electron microscope (TEM) and scanning electron microscope (SEM). The results show that the hardening effect of the first stage is decreased, the hardness and tensile strength are significantly improved, the time of peak aged is aheaded and the ductility is decreased in T8 condition aged at 180°C for comparison to that of T6 condition, T8 treatment promotes a more homogeneous distribution of the fined and dispersed θ′ phase and reduces the number of θ′ (θ) phase on grain boundaries which distributed in a more discrete manner and thus shrinks the total volume of precipitation-free zones at grain boundaries. It also improve intergranular corrosion resistance of alloy in the peak aged condition.