Electron probe microanalysis and SEM were employed to study the phase equilibria and diffusion paths in C Ni 8Ta, C Ni 3Ta, C Ni 2Ta diffusion couples after annealed at 1100 ℃ for 120 h or at 1200 ℃ for 120 h ...Electron probe microanalysis and SEM were employed to study the phase equilibria and diffusion paths in C Ni 8Ta, C Ni 3Ta, C Ni 2Ta diffusion couples after annealed at 1100 ℃ for 120 h or at 1200 ℃ for 120 h and then at 1100 ℃ for 24 h. Attempt was made to use the calculated stability diagram of carbon activity to explain the experimental observations. The phases formed in the diffusion layers were all in the prediced ranges.展开更多
After diffusion couples were annealed at 260-360 ℃, the concentration profiles of Zn element were measured by EPMA. It has been first quantitatively determined by Matano method that the interdiffusion coefficient in ...After diffusion couples were annealed at 260-360 ℃, the concentration profiles of Zn element were measured by EPMA. It has been first quantitatively determined by Matano method that the interdiffusion coefficient in A1-Zn fee solid solution containing high Zn contents is remarkably decreased due to the small addition of Cu. Also, the interdiffusion coefficient in A1-Zn fee solid solution clearly increases with the increasing of Zn concentration. The interdiffusion activity energy remarkably decreases with the increasing of Zn contents. On the other hand, the interdiffusion activity energy markedly increases due to the small addition of Cu in the A1 Zn fcc solid solution containing high Zn contents.展开更多
文摘Electron probe microanalysis and SEM were employed to study the phase equilibria and diffusion paths in C Ni 8Ta, C Ni 3Ta, C Ni 2Ta diffusion couples after annealed at 1100 ℃ for 120 h or at 1200 ℃ for 120 h and then at 1100 ℃ for 24 h. Attempt was made to use the calculated stability diagram of carbon activity to explain the experimental observations. The phases formed in the diffusion layers were all in the prediced ranges.
文摘After diffusion couples were annealed at 260-360 ℃, the concentration profiles of Zn element were measured by EPMA. It has been first quantitatively determined by Matano method that the interdiffusion coefficient in A1-Zn fee solid solution containing high Zn contents is remarkably decreased due to the small addition of Cu. Also, the interdiffusion coefficient in A1-Zn fee solid solution clearly increases with the increasing of Zn concentration. The interdiffusion activity energy remarkably decreases with the increasing of Zn contents. On the other hand, the interdiffusion activity energy markedly increases due to the small addition of Cu in the A1 Zn fcc solid solution containing high Zn contents.
