2A70铝合金环件胀形强化微观机制的试验研究  

Experiment Study on Bulging Strengthening Microscopic Mechanism of 2A70 Aluminum Alloy Ring

作　　者：江道 易幼平[1,2] 黄始全 JIANG Dao YI Youping HUANG Shiquan(State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China Hight Alloy Research Institute, Central South University, Changsha 410083, China)

机构地区：[1]中南大学高性能复杂制造国家重点实验室,湖南长沙410083 [2]中南大学轻合金研究院,湖南长沙410083

出　　处：《热加工工艺》2017年第20期75-78,共4页Hot Working Technology

基　　金：国家重点基础研究发展规划项目(2012CB619504);高性能复杂制造国家重点实验室自由探索项目(zzyjkt2014-02)

摘　　要：结合2A70铝合金环件胀形工艺研究的需要,采用拉伸试验、扫描电镜、透射电镜研究胀形强化的微观机制。结果表明:经过胀形工艺的铝合金环件拉伸强度明显提高,但伸长率略有下降;胀形工艺为合金引入大量位错,有利于基体中空位和溶质的扩散,促进合金强化相—S相的均匀析出,并使无沉淀析出带变窄;大量弥散分布的S相缩小第二相质点间距,位错绕过质点应力增大,有利于提高合金的强度;较窄的无沉淀析出带会导致塑性下降。Combined with the necessary of studying bulging forming of 2A70 aluminum alloy ring, the microscopic mechanisms of bulging strengthening were investigated by tensile test, scanning electron microscope and transmission electron microscope. The results show that after bulging forming, the tensile strength of the aluminum alloy ring increases obviously, but the ductility decreases a little. The bulging forming introduces a large number of dislocations into alloy, which is beneficial to the spread of vacancies and solute in matrix, and promotes the uniform distribution of strengthening phase--S phase precipitation, and makes PFZ （precipitate free zone） narrow. A large number of dispersed S-phase narrows the particle space, and the bypassing stress of the dislocation increases, which is beneficial to improve the strength of the alloy. The narrowed PFZ can lead to the decrease of plasticity.

关 键 词：2A70铝合金 胀形工艺 时效 微观组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]