The new developedγ/γʹCo–Al–Nb-base alloys show great potentials as high-temperature materials.However,finding appropriate compositions to improve performance of alloys still poses a great challenge to the developm...The new developedγ/γʹCo–Al–Nb-base alloys show great potentials as high-temperature materials.However,finding appropriate compositions to improve performance of alloys still poses a great challenge to the development of Co–Al–Nb-base alloys.Motivated by the lack of alloying effects on fundamental properties of criticalγʹphase,we systematically performed a theoretical investigation on the effect of alloying elements TM(TM:Ti,V,Cr,Zr,Mo,Ta,W,Re,and Ru)on phase stabilities and mechanical properties of L1_(2)-typeγʹ(Co,Ni)_(3)(Al,Nb).By analyzing the stability ofγʹphase with respect to its competitive B2 and D0_(19) phases,the results shown that Ti,V,and Cr enhance the L1_(2) stability and widen the L1_(2)–D0_(19) energy barrier,in which V yields the maximum influence.The analysis of electronic structure indicated that the alternation of valence electrons at fermi level would be the atomic origin for doping TM inγʹphase.The calculated results of mechanical properties shown that V and Cr are expected to be optimal dopant for enhancing the strength and the ductility ofγʹphase.The addition of Ta is also beneficial for enhancing the strength at the slight expense of ductility ofγʹphase.By drawing the mechanical maps,the preferred composition range for the phases with desired properties is roughly demarcated in theory for the multi-addition of V/Cr and V/Ta inγʹphase.The findings would be useful for optimizing the performance of novelγ/γʹCo–Al–Nb-base superalloys.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52371014 and U22B20132)the Shenzhen Science and Technology Program(No.JCYJ20230807091401004)+1 种基金the Fundamental Research Funds for the Central Universities(No.20720230036)the Guided Subject of Dean’s Fund(No.YZJJ-YDL-0004).
文摘The new developedγ/γʹCo–Al–Nb-base alloys show great potentials as high-temperature materials.However,finding appropriate compositions to improve performance of alloys still poses a great challenge to the development of Co–Al–Nb-base alloys.Motivated by the lack of alloying effects on fundamental properties of criticalγʹphase,we systematically performed a theoretical investigation on the effect of alloying elements TM(TM:Ti,V,Cr,Zr,Mo,Ta,W,Re,and Ru)on phase stabilities and mechanical properties of L1_(2)-typeγʹ(Co,Ni)_(3)(Al,Nb).By analyzing the stability ofγʹphase with respect to its competitive B2 and D0_(19) phases,the results shown that Ti,V,and Cr enhance the L1_(2) stability and widen the L1_(2)–D0_(19) energy barrier,in which V yields the maximum influence.The analysis of electronic structure indicated that the alternation of valence electrons at fermi level would be the atomic origin for doping TM inγʹphase.The calculated results of mechanical properties shown that V and Cr are expected to be optimal dopant for enhancing the strength and the ductility ofγʹphase.The addition of Ta is also beneficial for enhancing the strength at the slight expense of ductility ofγʹphase.By drawing the mechanical maps,the preferred composition range for the phases with desired properties is roughly demarcated in theory for the multi-addition of V/Cr and V/Ta inγʹphase.The findings would be useful for optimizing the performance of novelγ/γʹCo–Al–Nb-base superalloys.
