Hot deformation behavior and microstructure evolution of the Cu-7Ni-7Al-4Fe-2Mn(-0.6Cr) alloys

In this paper, the effects of Cr on the hot deformation behavior, precipitated phase characteristics and microstructure of Cu-7Ni-7Al-4Fe-2Mn alloy were studied. The hot compression test of the alloy was carried out by thermal simulation tester, and the flow stress, grain size and precipitated phase type of the alloy under different deformation parameters were analyzed by means of EBSD and TEM. The results show that the addition of Cr significantly increases the flow stress and hot deformation activation energy of the alloy, and promotes the dynamic recrystallization behavior of the alloy. TEM analysis shows that the addition of Cr changes the type of Fe-rich phase in the alloy, from the original FCC structure γ-Fe phase to the L1 2 structure Fe 3 Cr phase, and enhances the pinning effect of the second phase dislocation, thereby significantly increasing the peak stress of the alloy. In addition, the optimum hot processing parameters of the two alloys were determined by hot processing map analysis, which provided a theoretical basis for optimizing the hot processing technology of the alloys. • Cr promotes the DRX behavior of the alloy. • Cr changed the type of Fe-rich phase in the alloy. • The pinning effect of Fe 3 Cr on dislocations is stronger than that of γ-Fe. • Cr enlarges the hot working safety zone of the alloy.