It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of gr...It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of grains has its own domain and dislocation structure. There are mono- and polydomains with and without dislocations. The grains of the main phase of monoand polydomains without dislocations and polydomains with dislocations were formed by diffusion in the solid phase. In these conditions NiAl3 phase is located on the grain boundary of the main phase. The Ni2Al3 phase is located at the triple joints of the main phase.展开更多
A phase and microstructure selection map used for peritectic alloy directionally solidified under convection condition was presented,which is based on the nucleation,constitutional undercooling criterion（NCU criterio...A phase and microstructure selection map used for peritectic alloy directionally solidified under convection condition was presented,which is based on the nucleation,constitutional undercooling criterion（NCU criterion）,and the highest interface temperature criterion.This selection map shows the relationships between the phase/microstructure,the G/V ratio（G is the temperature gradient,V is the growth velocity）,and the alloy composition under different convection intensities and nucleation undercoolings.Comparing with the results from directional solidification experiments of Sn–Cd peritectic alloys,this selection map was generally in agreement with the experimental results.展开更多
文摘It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of grains has its own domain and dislocation structure. There are mono- and polydomains with and without dislocations. The grains of the main phase of monoand polydomains without dislocations and polydomains with dislocations were formed by diffusion in the solid phase. In these conditions NiAl3 phase is located on the grain boundary of the main phase. The Ni2Al3 phase is located at the triple joints of the main phase.
基金financially supported by the National Natural Science Foundation of China (No.50774061)the Research Fund of State Key Laboratory of Solidification Processing (NWPU) (No.28-TP-2009)
文摘A phase and microstructure selection map used for peritectic alloy directionally solidified under convection condition was presented,which is based on the nucleation,constitutional undercooling criterion（NCU criterion）,and the highest interface temperature criterion.This selection map shows the relationships between the phase/microstructure,the G/V ratio（G is the temperature gradient,V is the growth velocity）,and the alloy composition under different convection intensities and nucleation undercoolings.Comparing with the results from directional solidification experiments of Sn–Cd peritectic alloys,this selection map was generally in agreement with the experimental results.
