【摘要】 利用透射电镜能谱法(TEM-EDX)研究了GH742合金中γ′和γ基体两相成分随温度和时效时间的变化规律。结果表明:合金在1050℃时效时,γ′相和γ基体的成分在时效初期变化较大,当时效时间超过1440min后,γ′相和γ基体的成份基本稳定。合金在750～1100℃时效时,γ′相和γ基体的成分均随着温度的升高而发生变化,其中γ基体的成分随温度变化较明显。合金中各元素在γ′和γ两相中的偏析率Cγ′/Cγ变化规律研究表明:Ti,Al,Nb,Ni等γ′形成元素的偏析率均随着时效温度的升高而降低,而Cr,Co,Mo等γ形成元素的偏析率均随着时效温度的升高而增大。更多还原

【Abstract】 The phase composition of γ’ phase and γ matrix in GH742 was investigated by energy dispersive of X-ray spectroscopy(EDX) in an analysis transmission electron microscope(TEM-EDX).The dependence of composition of γ’ and γ phase on aging time indicates that the composition of γ’ and γ phase evolves drastically in short aging time at the temperature of 1050℃ and reaches the equilibrium condition when aging for 1440 min.The dependence of composition of γ’ and γ phase on temperature indicates that the composition of γ’ and γ phases evolves with the increasing temperature in the range of 750℃ to 1100℃.The dependence of partitioning ratios Cγ’/Cγon temperature shows that the partitioning ratios Cγ’/Cγ of γ’-forming elements Ti,Al,Nb,Ni have a decrease and those of γ-forming elements Cr,Co,Mo have an increase with the temperature increasing.更多还原