The microstructure, hot flow stress behavior, and fracture mechanism of spray-formed and extruded (SFEed) Al-12Zn-2.4Mg-1.1Cu-0.3Zr alloy were investigated by uniaxial tensile stress over temperature range 523-673 K and strain rate range 0.00005-0.05 s⁻¹. The interaction among activation energy and deformation parameters was analyzed. An Arrhenius-based constitutive equation was proposed to determine the peak flow stress of SFEed Al-12Zn-2.4Mg-1.1Cu-0.3Zr alloy. The results reveal that the recrystallization degree and MgZn₂ phase content as well as dislocation density for various deformation conditions are vital for peak flow stress. The studied alloy exhibits superior peak flow stress by the high alloying elements and RRA heat treatment. The transformation of fracture mechanism from void coalescence to intergranular fracture is mainly caused by the interaction between dislocation and MgZn₂ phase. Low activation energy on the case of high temperature is contributed by the reduction of energy barrier for dislocation motion caused by microstructure evolution. The proposed constitutive equation can determine the peak flow stress with reasonable precision by analysis of standard statistical parameters.

通过在523-673 K温度范围和应变速率范围内的单轴拉伸应力研究了喷射成型和挤压（SFEed）Al - 12Zn - 2.4Mg - 1.1Cu - 0.3Zr合金的显微组织，热流应力行为和断裂机理。0.00005-0.05 s ^-1。分析了活化能和变形参数之间的相互作用。提出了一种基于Arrhenius的本构方程来确定SFEed Al - 12Zn - 2.4Mg - 1.1Cu - 0.3Zr合金的峰值流应力。结果表明，再结晶度和MgZn ₂各种变形条件下的相含量和位错密度对于峰值流应力至关重要。所研究的合金通过高合金元素和RRA热处理表现出优异的峰值流应力。断裂机理由空隙合并转变为晶间断裂的主要原因是位错与MgZn ₂相的相互作用。高温情况下的低活化能归因于微结构演化引起的位错运动的能垒的减少。通过对标准统计参数的分析，所提出的本构方程可以确定合理的峰值流应力。