(1. 湖南工业大学 冶金与材料工程学院，株洲 412007；
2. 中国中车 株洲电力机车有限公司，株洲 412007)
摘 要: 采用扫描电镜(SEM)、透射电镜(TEM)、电子背散射技术(EBSD) 、能谱仪(EDS)和拉伸测试等手段，研究快速冷冲及再结晶退火对喷射成形快速凝固细晶Al-Cu-Mg合金微观组织和力学性能的影响。结果表明：细晶Al-Cu-Mg合金在快速冷冲及再结晶退火过程中析出相主要以平衡相S相为主，还有少量较粗的Al6Mn相，随着变形道次的增加，析出相的密度不断增大、尺寸显著减小。快速冷冲引入的缺陷有助于Al-Cu-Mg合金脱溶和再结晶形核，促进S相和再结晶的形核与长大，从而有效细化晶粒、获得均匀纳米晶组织和促进S相弥散分布。快速冷冲Al-Cu-Mg合金的主要强韧化机制是细晶强化和析出强化，经4道次快速冷冲后合金的极限抗拉强度和伸长率分别达578MPa和17.5%，与1道次快速冷冲合金试样的相比较，极限抗拉强度提高48.5%，伸长率提高44.6%。
关键字: 喷射成形；Al-Cu-Mg合金；快速冷冲；再结晶退火；析出相；力学性能
（1. School of Metallurgical and Material Engineering, Hunan University of Technology, Zhuzhou 412007, China;
2. CRRC Zhuzhou Electric Locomotive Co., Ltd., Zhuzhou 412007, China）
Abstract:The effect of rapid cold punching and recrystallization annealing on the microstructure and mechanical properties of Al-Cu-Mg alloy with fine grain produced by spray forming process was studied by the analysis methods, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron back scatter diffraction(EBSD), energy disperse spectroscopy (EDS) and the tensile test. The results indicate that S phase as the equilibrium phase is precipitated in the Al-Cu-Mg alloy matrix in the process of the rapid cold punching and the recrystallization annealing, and a small amount of coarse phase Al6Mn is also precipitated at the same time. The density of the precipitated phase becomes larger and the particle size becomes smaller with increasing of the passes number. The crystal defects made in the process of the rapid cold stamping are useful for the alloy phase ex-solution, and also benefit for the nucleation and growth of the S phase, which is effective to obtain the refined grain, the homogeneous nanocrystalline structure, and uniformly distributed S phase. The main strength mechanism of the Al-Cu-Mg alloy prepared by rapid cold punching is fine grain strengthening and precipitation strengthening. Ultimate tensile strength and elongation of the alloy after 4 passes are 578 MPa and 17.5%, respectively. And the ultimate tensile strength and elongation of the alloy with 4 passes are increased by 48.5% and 44.6% compared with the alloy with 1 pass.
Key words: spray forming; Al-Cu-Mg alloy; rapid cold punching; recrystallization annealing; precipitated phase; mechanical property
