The microstructure and precipitation characteristics of 22Cr-14W-2Mo superalloys added with various La contents have been studied by SEM, TEM and EDX.It is found that the carbides are refined by adding La.M23C6 carbid...The microstructure and precipitation characteristics of 22Cr-14W-2Mo superalloys added with various La contents have been studied by SEM, TEM and EDX.It is found that the carbides are refined by adding La.M23C6 carbides inside the grain in a diameter of 50 nm have a cube-cube orientation relationship with the matrix, and these precipitates on {111} planes align along 110 orientation.Since the large dissolved La atom will be a barrier to atom diffusion, it leads to an inhibiting effect on the carbides growing.M6C carbides are influenced by La-S phases.La-S phases formed in the center of M6C seem to be the heterogeneous nucleus of M6C to increase the nucleation ratio.It is also noticed that finer M6C carbides precipitated on the {111} planes of the matrix are around large M6C.The finer M6C carbides are caused by the special absorption effect of La-S phases.展开更多
An external electric field was applied on GH4169 superalloy during aging at 700℃ in order to study the hardness variation.The results indicate that the amount of vacancies in the matrix increase after electric field ...An external electric field was applied on GH4169 superalloy during aging at 700℃ in order to study the hardness variation.The results indicate that the amount of vacancies in the matrix increase after electric field treatment and some monovacancies changes into the vacancy clusters.Vacancy flow forms and the segregation of Fe and Cr atoms of the alloy generates because of the non-equilibrium distribution of electric field induced by the charged surfaces.Since the severe lattice distortion will occur at the local area,the specimen is hardened.展开更多
基金supported by the Program for Changjiang Scholars and Innovative Research Teams in Chinese Universities (No. IRT0713)the National Natural Science Foundation of China (No. 50841025)
文摘The microstructure and precipitation characteristics of 22Cr-14W-2Mo superalloys added with various La contents have been studied by SEM, TEM and EDX.It is found that the carbides are refined by adding La.M23C6 carbides inside the grain in a diameter of 50 nm have a cube-cube orientation relationship with the matrix, and these precipitates on {111} planes align along 110 orientation.Since the large dissolved La atom will be a barrier to atom diffusion, it leads to an inhibiting effect on the carbides growing.M6C carbides are influenced by La-S phases.La-S phases formed in the center of M6C seem to be the heterogeneous nucleus of M6C to increase the nucleation ratio.It is also noticed that finer M6C carbides precipitated on the {111} planes of the matrix are around large M6C.The finer M6C carbides are caused by the special absorption effect of La-S phases.
基金Item Sponsored by National Natural Science Foundation of China[No.51171039]973 Program of China[2010CB631203]+1 种基金the Fundamental Research Funds for the Central University of China[N100602002]the 2010 Academy Awards Sponsorship of Doctoral Candidate for Newcomer of China[22002096]
文摘An external electric field was applied on GH4169 superalloy during aging at 700℃ in order to study the hardness variation.The results indicate that the amount of vacancies in the matrix increase after electric field treatment and some monovacancies changes into the vacancy clusters.Vacancy flow forms and the segregation of Fe and Cr atoms of the alloy generates because of the non-equilibrium distribution of electric field induced by the charged surfaces.Since the severe lattice distortion will occur at the local area,the specimen is hardened.
