(1. 湖南工業(yè)大學(xué) 冶金與材料工程學(xué)院，株洲 412007；
2. 中國中車 株洲電力機(jī)車有限公司，株洲 412007)
摘 要: 采用掃描電鏡(SEM)、透射電鏡(TEM)、電子背散射技術(shù)(EBSD) 、能譜儀(EDS)和拉伸測試等手段，研究快速冷沖及再結(jié)晶退火對噴射成形快速凝固細(xì)晶Al-Cu-Mg合金微觀組織和力學(xué)性能的影響。結(jié)果表明：細(xì)晶Al-Cu-Mg合金在快速冷沖及再結(jié)晶退火過程中析出相主要以平衡相S相為主，還有少量較粗的Al6Mn相，隨著變形道次的增加，析出相的密度不斷增大、尺寸顯著減小。快速冷沖引入的缺陷有助于Al-Cu-Mg合金脫溶和再結(jié)晶形核，促進(jìn)S相和再結(jié)晶的形核與長大，從而有效細(xì)化晶粒、獲得均勻納米晶組織和促進(jìn)S相彌散分布。快速冷沖Al-Cu-Mg合金的主要強(qiáng)韌化機(jī)制是細(xì)晶強(qiáng)化和析出強(qiáng)化，經(jīng)4道次快速冷沖后合金的極限抗拉強(qiáng)度和伸長率分別達(dá)578MPa和17.5%，與1道次快速冷沖合金試樣的相比較，極限抗拉強(qiáng)度提高48.5%，伸長率提高44.6%。
關(guān)鍵字: 噴射成形；Al-Cu-Mg合金；快速冷沖；再結(jié)晶退火；析出相；力學(xué)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
