中文摘要：

采用形变热处理法制备7B04铝合金细晶板材,利用EBSD和高温拉伸等实验方法研究退火过程中升温速率对板材晶粒组织和超塑性的影响。结果表明：升温速率为5.0×10^-3K/s时,退火后板材的轧向和法向的平均晶粒尺寸分别为28.2μm和13.9μm,形核效率为1/1000。随着升温速率的提高,合金平均晶粒尺寸不断减小,形核效率不断提升。当升温速率提高至30.0K/s时,其轧向和法向的平均晶粒尺寸分别降低至9.9μm和5.1μm,形核效率提升至1/80。此外,板材的伸长率也随着升温速率的提高而增大,在773K/8×10^-4s^-1的变形条件下,试样的伸长率从100%提高至730%。

英文摘要：

Fine-grained 7B04 aluminum alloy sheets were manufactured through thermo-mechanical treatment.The effects of anneal heating rate on grain structure and superplasticity were investigated using electron back scattering diffraction（EBSD）and high temperature tensile test.The results show that at the heating rate of 5.0×10^-3K/s,the average grain sizes along the rolling direction（RD）and normal direction（ND）are 28.2μm and 13.9μm respectively,the nucleation rate is 1/1000.With the increase of heating rate,the average grain size decreases,and the nucleation rate increases.When the heating rate increases to 30.0K/s,the average grain sizes along the RD and ND decrease respectively to 9.9μm and 5.1μm,and the nucleation rate increases to 1/80.Besides,with the increase of heating rate,the elongation of sheets also increases.The elongation of the specimens increases from 100%to730% under the deforming condition of 773K/8×10^-4s^-1.