The static recrystallization behavior of 7075 aluminum alloy containing Al_(3)(Sc,Zr)phase prepared by casting and the relationship between recrystallization behavior and mechanical properties were studied.The additio...The static recrystallization behavior of 7075 aluminum alloy containing Al_(3)(Sc,Zr)phase prepared by casting and the relationship between recrystallization behavior and mechanical properties were studied.The addition of Sc and Zr made the Sc−Zr−7075 aluminum alloy remain the most of fibrous structure and high-density dislocations formed in the extrusion process,resulting in the recrystallization fraction of the alloy decreasing from 35%to 22%,and the corresponding fraction of substructure increasing from 59%to 67%.The Sc and Zr effectively inhibited the recrystallization behavior of 7075 aluminum alloy mainly,which was attributed to the fact that the existence of fine and coherent Al_(3)(Sc,Zr)phase(r=35 nm,f=1.8×10^(−3))strongly pined the dislocations and grain boundaries,preventing the dislocations from rearranging into sub-grain boundaries and from developing into high angle grain boundaries,and further hindering the formation and growth of recrystallized core of the alloy.展开更多
Gr/CuCr10 alloys with graphene contents of 0.1 wt.%,0.3 wt.%,0.5 wt.%,and 0.7 wt.%were prepared by a hot pressing sintering process.Compared with CuCr10 alloy,the relative density of CuCr10 composite with 0.3 wt.%addi...Gr/CuCr10 alloys with graphene contents of 0.1 wt.%,0.3 wt.%,0.5 wt.%,and 0.7 wt.%were prepared by a hot pressing sintering process.Compared with CuCr10 alloy,the relative density of CuCr10 composite with 0.3 wt.%addition of graphene remained constant,while the electrical conductivity increased from 62.2%(IACS)to 69.5%(IACS).The main reason for the increased electrical conductivity is that the addition of graphene leads to the size reduction of Cr phase and thus reduces the scattering of electrons.In addition,Brinell’s hardness of 0.3 wt.%Gr/CuCr10 composite increased from HB 91.8 to HB 99.6 compared with that of CuCr10 alloy.The graphene was mainly distributed at the interface of Cu and Cr.A nano-Cr;C;phase,which has been observed through HRTEM,is the main reason for the wettability enhancement at the interface of Cu and Cr,thus improving the hardness of the material.展开更多
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(No.51871111)the Natural Science Foundation of Shandong Province,China(No.ZR2018LE001)+1 种基金the Science and Technology Program of University of Ji’nan,China(Nos.XKY2036,XKY1713)the Key Research and Development Program of Shandong Province,China(No.2019GGX102008).
文摘The static recrystallization behavior of 7075 aluminum alloy containing Al_(3)(Sc,Zr)phase prepared by casting and the relationship between recrystallization behavior and mechanical properties were studied.The addition of Sc and Zr made the Sc−Zr−7075 aluminum alloy remain the most of fibrous structure and high-density dislocations formed in the extrusion process,resulting in the recrystallization fraction of the alloy decreasing from 35%to 22%,and the corresponding fraction of substructure increasing from 59%to 67%.The Sc and Zr effectively inhibited the recrystallization behavior of 7075 aluminum alloy mainly,which was attributed to the fact that the existence of fine and coherent Al_(3)(Sc,Zr)phase(r=35 nm,f=1.8×10^(−3))strongly pined the dislocations and grain boundaries,preventing the dislocations from rearranging into sub-grain boundaries and from developing into high angle grain boundaries,and further hindering the formation and growth of recrystallized core of the alloy.
基金financially supported by the National Natural Science Foundation of China(No.51871111)Jinan Changan Graphene Aluminum Material Technology Co.,Ltd.,Chinathe Dingmei New Material Technology Co.,Ltd.,China。
文摘Gr/CuCr10 alloys with graphene contents of 0.1 wt.%,0.3 wt.%,0.5 wt.%,and 0.7 wt.%were prepared by a hot pressing sintering process.Compared with CuCr10 alloy,the relative density of CuCr10 composite with 0.3 wt.%addition of graphene remained constant,while the electrical conductivity increased from 62.2%(IACS)to 69.5%(IACS).The main reason for the increased electrical conductivity is that the addition of graphene leads to the size reduction of Cr phase and thus reduces the scattering of electrons.In addition,Brinell’s hardness of 0.3 wt.%Gr/CuCr10 composite increased from HB 91.8 to HB 99.6 compared with that of CuCr10 alloy.The graphene was mainly distributed at the interface of Cu and Cr.A nano-Cr;C;phase,which has been observed through HRTEM,is the main reason for the wettability enhancement at the interface of Cu and Cr,thus improving the hardness of the material.
