(中南大学 材料科学与工程学院， 长沙 410083)
摘 要: 采用硬度测试、 扫描电镜与透射电镜研究时效前冷轧预变形量对2519铝合金晶界无沉淀带(PFZ)及第二相大小、 分布和抗晶间腐蚀性能的影响。 结果表明： 经冷轧预变形后， 晶间析出相细化并弥散分布， 导致各变形量样品的时效硬度均提高， 同时使合金到达峰值的时效时间缩短； 且随着预变形量的增加， 合金晶间腐蚀性能由4级降至0级， 抗晶间腐蚀能力增强。 这是由于晶界无沉淀带变窄， 同时在晶界析出的平衡相由链条状分布逐渐变为不连续分布， 使连续网状的腐蚀通道转变为断续的腐蚀点， 进而提高了2519合金的抗晶间腐蚀性能。
关键字: 预变形量; 晶间腐蚀; 2519铝合金
（School of Materials Science and Engineering, Central South University,
Changsha 410083, China）
Abstract: By hardness tests, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the influence of predeformation reduction before aging on the size and distribution of precipitate phases and inter-granular corrosion resistance of 2519 alloy was determined. The results show that the precipitate in grains is fined after predeformation reduction. The peak-age hardness of samples is correspondingly improved, and the time for peak-aged is shortened. With the increase of the predeformation reduction, the rate of intergranular corrosion (IGC) of 2519 aluminum alloys decreases from 4 to 0, and the IGC resistance is improved. Along grain boundaries, the precipitation free zones (PFZ) is narrow and the distribution of those precipitates changes from continuous chains to non-continuous ones. Then, the discrete corrosion pits form instead of continuous pathway, which results in higher IGC resistance.
Key words: degree of predeformation; intergranular corrosion; 2519 aluminum alloys
