An Al-Cu-Mg-Zr alloy,which obtained different homogenization cooling rates by changing the heattreated sample size,was compressed to various strains at the deformation temperature of 300℃ and strain rate of 0.01 s^(-...An Al-Cu-Mg-Zr alloy,which obtained different homogenization cooling rates by changing the heattreated sample size,was compressed to various strains at the deformation temperature of 300℃ and strain rate of 0.01 s^(-1).The results showed that the homogenization cooling rate had strong effects on the hot deformation behavior of the alloy.The flow stress and relative dynamic softening rate of the alloy were significantly higher under a high cooling rate(HCR) than those under a low cooling rate(LCR).Furthermore,based on X-ray diffraction,scanning electron microscopy,transmission electron microscopy,and thermodynamic equilibrium phase calculation,the substructure evolution in the grain interior,morphology,and spatial distribution of the precipitates were studied to determine the differences in the flow softening mechanism.The main softening mechanism could be summarized as dynamic recovery and precipitation coarsening for the LCR alloy and dynamic precipitation for the HCR alloy.展开更多
The billets of Al-Zn-Mg-Cu-Zr and Al-Zn-Mg-Cu-Zr-0.5Er alloys were prepared by semi-continuous direct chill casting （DCC）.The effects of trace Er on microstructure of Al-Zn-Mg-Cu-Zr alloy under as-cast and homogeniz...The billets of Al-Zn-Mg-Cu-Zr and Al-Zn-Mg-Cu-Zr-0.5Er alloys were prepared by semi-continuous direct chill casting （DCC）.The effects of trace Er on microstructure of Al-Zn-Mg-Cu-Zr alloy under as-cast and homogenization conditions were studied.The results show that the grain morphology is large dendritic structure and the grain size increases obviously by the addition of 0.5% Er.Moreover,most of Er element in the alloy segregates at grain boundary during solidification,resulting in ternary Al8Cu4Er phase.After homogenization,most of the MgZn2 phase at grain boundary has dissolved back to Al matrix in the two alloys.In the Er-containing alloy,the dissolution temperature of Al8Cu4Er phase is about 575 °C.Therefore,the homogenization treatment cannot eliminate Al8Cu4Er phase validity.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51674111 and51605234)the Research Fund for the Doctoral Program of Higher Education of China(No.20130161110007)。
文摘An Al-Cu-Mg-Zr alloy,which obtained different homogenization cooling rates by changing the heattreated sample size,was compressed to various strains at the deformation temperature of 300℃ and strain rate of 0.01 s^(-1).The results showed that the homogenization cooling rate had strong effects on the hot deformation behavior of the alloy.The flow stress and relative dynamic softening rate of the alloy were significantly higher under a high cooling rate(HCR) than those under a low cooling rate(LCR).Furthermore,based on X-ray diffraction,scanning electron microscopy,transmission electron microscopy,and thermodynamic equilibrium phase calculation,the substructure evolution in the grain interior,morphology,and spatial distribution of the precipitates were studied to determine the differences in the flow softening mechanism.The main softening mechanism could be summarized as dynamic recovery and precipitation coarsening for the LCR alloy and dynamic precipitation for the HCR alloy.
基金Project(ZR2021QE136)supported by the Natural Science Foundation of Shandong Province,ChinaProject(2020B010186002)supported by the Key Research and Development Program of Guangdong Province,China。
基金Project(50875031) supported by the National Natural Science Foundation of ChinaProject(2005CB623705) supported by National Basic Research Program of China
文摘The billets of Al-Zn-Mg-Cu-Zr and Al-Zn-Mg-Cu-Zr-0.5Er alloys were prepared by semi-continuous direct chill casting （DCC）.The effects of trace Er on microstructure of Al-Zn-Mg-Cu-Zr alloy under as-cast and homogenization conditions were studied.The results show that the grain morphology is large dendritic structure and the grain size increases obviously by the addition of 0.5% Er.Moreover,most of Er element in the alloy segregates at grain boundary during solidification,resulting in ternary Al8Cu4Er phase.After homogenization,most of the MgZn2 phase at grain boundary has dissolved back to Al matrix in the two alloys.In the Er-containing alloy,the dissolution temperature of Al8Cu4Er phase is about 575 °C.Therefore,the homogenization treatment cannot eliminate Al8Cu4Er phase validity.
