中文摘要：

通过等温压缩试验研究AA2014锻造铝合金的热变形行为。试验在Gleeble-3180热模拟机上进行，温度和应变速率范围分别为350~480°C和0.001~1s-1。利用金相显微镜(OM)、电子背散射衍射(EBSD)、透射电子显微镜(TEM)等分析手段观察合金在不同变形条件下的显微组织，并构建应变为0.1、0.3、0.5和0.7时的加工图。结果表明：高应变速率(>0.1s-1)时易出现失稳变形区，并以局部不均匀变形为主要失稳形式。当应变为0.7时，加工图中存在两个稳定变形区：I区(350~430°C，0.005~0.1s-1)和Ⅱ区(450~480°C，0.001~0.05s-1)，其主要软化机制均为动态回复。在变形区I中得到均匀的显微组织，在变形区Ⅱ中发生扩展回复，这将导致潜在的亚晶界逐步转变为新的大角度晶界。AA2014锻造铝合金的最佳热加工参数如下：温度370~420°C，应变速率0.008~0.08s-1。

英文摘要：

The hot deformation behavior of AA2014forging aluminum alloy was investigated by isothermal compression tests attemperatures of350-480°C and strain rates of0.001-1s-1on a Gleeble-3180simulator.The corresponding microstructures of thealloys under different deformation conditions were studied using optical microscopy(OM),electron back scattered diffraction(EBSD)and transmission electron microscopy(TEM).The processing maps were constructed with strains of0.1,0.3,0.5and0.7.The results showed that the instability domain was more inclined to occur at strain rates higher than0.1s-1and manifested in theform of local non-uniform deformation.At the strain of0.7,the processing map showed two stability domains:domain I(350-430°C,0.005-0.1s-1)and domain II(450-480°C,0.001-0.05s-1).The predominant softening mechanisms in both of the twodomains were dynamic recovery.Uniform microstructures were obtained in domain I,and an extended recovery occurred in domainII,which would lead to the potential sub-grain boundaries progressively transforming into new high-angle grain boundaries.Theoptimum hot working parameters for the AA2014forging aluminum alloy were determined to be370-420°C and0.008-0.08s-1.