Zn元素及时效工艺对2056铝合金微观组织和力学性能的影响  

Effects of Zn additions and aging process on microstructure and mechanical properties 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] 廖忠全[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《中国有色金属学报》2012年第9期2477-2485,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2012CB619503)

摘　　要：通过显微硬度测试、常规拉伸性能测试、DSC分析和透射电镜观察,研究少量Zn元素及时效工艺对2056铝合金微观组织与力学性能的影响。结果表明:在T6、T8和T3时效状态下,2056合金的抗拉强度(σb)和屈服强度(σ0.2)均比不含Zn合金的高,而伸长率(δ)相差不大,这是因为Zn的添加形成富Zn团簇,促进GPB区的形成,进一步促进S′相的析出,提高合金强度。2056合金在T6、T8峰时效态和T3态下的σb和σ0.2由大到小顺序为T8,T3和T6,时效前的预变形形成大量位错,由于位错和溶质原子强烈的交互作用,形成大量的位错塞积和缠结,增加了T3态合金的强度;在T8态下,大量的位错成为S′相的形核点,使合金形成细小、密集和均匀弥散的S′相,其强度较T6和T3态的得到较大提高。The effects of Zn additions and aging process on the microstructure and mechanical properties of 2056 aluminum alloy were investigated by micro-hardness test, tensile test, differential scanning calorimetry （DSC） and transmission electron microscopy （TEM）. The results show that the tensile strength （δb） and yield strength （δ0.2） of 2056 aluminum alloy are higher than those of the alloy without Zn while the elongation is almost the same in T6, T8 and T3 temper. This is because with the addition of Zn, Zn-rich clusters form, which accelerates the precipitation of GPB zone and the precipitation of S＇ phase further, thus improving the strength of the alloy. The order of δb and δ0.2 of 2056 aluminum alloy in T3, peak-aged T6 and T8 temper from large to small is T8, T3 and T6. The predeformation before aging makes plenty of dislocations form. Due to the strong interaction between the solute atoms and dislocations, there exists large quantity of dislocation pile-up while dislocations become tangled up, which improve the strength in T3 temper. In T8 temper, the dislocations become the precipitation sites of S＇ phase, making fine, dense and uniform S＇ phase in the matrix. The strength of the alloy in T8 temper improves a lot compared with that ofat and T3 temper.

关 键 词：2056铝合金 ZN 时效处理 力学性能 微观组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]