-1的條件下進(jìn)行熱拉伸試驗，研究了厚度為5 mm的7075合金傳統(tǒng)鑄軋板和電脈沖鑄軋板的微觀組織和熱成形性能。實驗用脈沖電流參數(shù)為：單周期脈寬0.005 s和峰值強(qiáng)度300 A。結(jié)果顯示，脈沖電流能夠促進(jìn)凝固過程的枝晶細(xì)化，并誘發(fā)組織均勻化。由于電磁振蕩增強(qiáng)了凝固過程中溶質(zhì)混合能力，極壓電流有效地促進(jìn)了晶粒細(xì)化和析出相的均勻化。同時，面心立方（fcc）鋁合金鑄軋板織構(gòu)具有{423}<144>取向，經(jīng)脈沖電流改性后，取向為{421}<216>。脈沖電流處理后的合金峰值流動應(yīng)力約為未處理合金的1.1~1.3倍。電子背散射衍射分析表明，脈沖電流通過促進(jìn)動態(tài)再結(jié)晶的方式，有效地改善了晶粒的擇優(yōu)分布。在此基礎(chǔ)上，分別建立了鋁合金帶材的雙曲正弦方程和含Zener-Holloman參數(shù)的本構(gòu)模型。此外，通過對斷口形貌的觀察發(fā)現(xiàn)，脈沖電流的引入有利于提高7075鋁合金的高溫機(jī)械性能。最后建立了優(yōu)化的工藝流程圖，并確定了適宜的熱加工溫度為290~330 ℃和應(yīng)變速率為0.001~0.002 s-1。;The microstructure and thermal formability of twin-roll cast 7075 alloy strips prepared with and without electrical pulse (EP) of 5 mm in thickness were investigated by hot tensile tests under the condition of deformation temperature of 250~350 °C and strain rate of 0.001~0.01 s-1. The related EP current parameters are as follows: the single cycle pulse width is 0.005 s; the pulse peak current is 300 A. The results show that the EP current effectively promotes the grain refinement and the precipitate homogeneousness, because the electromagnetic oscillation enhances the solute mixing ability during solidification. Meanwhile, the rolling textures of face-centered cubic (fcc) 7075 Al strips have the {423}<144> orientation. After EP current modification, the orientation of 7075 Al strips is {421}<216>. The peak flow stress of the 7075 alloy strips prepared with EP current is about 1.1~1.3 times larger than that of the original 7075 alloy strips. The electron back-scattered diffraction analysis shows that EP current can effectively improve the preferred distribution of the grains by promoting the dynamic recrystallization. Furthermore, the hyperbolic sine equation and the constitutive model with Zener-Holloman parameter are established based on the analyses. Besides, according to the fracture morphology, the EP current is beneficial to improve the mechanical properties of 7075 alloys at elevated temperature. Finally, the processing maps are established and the proper hot working parameters are designed as the temperature range of 290~330 °C and the strain rate of 0.001~0.002 s-1."/>