| Co-Investigator(Kenkyū-buntansha) |
TANAKA Toshihiro Faculty of Eng., Osaka Univ., Research Associate, 工学部, 助手 (10179773)
KITA Yoshifumi Faculty of Eng., Osaka Univ., Research Associate, 工学部, 助手 (80029115)
IIDA Takamichi Faculty of Eng., Osaka Univ., Associate Professor, 工学部, 助教授 (70029247)
|
|---|
| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥5,200,000)
Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1985: ¥4,700,000 (Direct Cost: ¥4,700,000)
|
|---|
| Research Abstract |
The purpose of this work is to measure and discuss thermodynamically the equilibrium distribution coefficient <k0^x> which is one of the most important factors to investigate various phenomena of the solidification of alloys, e. x. micro-segregation of solute elements.
First of all, the equilibrium distribution coefficients of phosphorus, <k0^p> in Fe-P and Fe-P-C ternary alloys were measured by use of a method, in which the specimen including solid-liquid coexisted phases was quenched and then the concentrations of solute elements were determined by EPMA. Temperature dependence of <k0^p> was also obtained. Furthermore, the variation of <k0^p> with carbon concentration was discussed using Distribution Interaction Coefficient, i.e. the parameter showing the effect of solute-interactions on <k0^x> in multi-component alloys, which was derived thermodynamically.
Second, the equilibrium distribution coefficients of Ni,Cr,Si,Mn and Mo were measured at several Cr and Ni compositions in Fe-Cr-Ni base alloys. In this experiment, the specimen was set in a furnace with temperature gradient and the upper part of the specimen was melted. After the solid-liquid interface was formed and then quenched, the concentration distributions near the interface were measured to determine <k0^x> .
Finally, the equilibrium distribution coefficients of 11 elements in Ni base binary alloys were measured in the same experimental method applied for Fe-Cr-Ni base alloys. The theoretical equations on <k0^x> in <Fe^-> , <Co^-> , and Ni-base alloys were derived on the basis of thermodynamics and elastic continuum theory, and the controlling factor of <k0^x> in those alloys could be evaluated quantitatively by these equations.
Some parts of the results described above have been already presented at the annual meeting, and those have been also published in Trans. ISIJ. The rest will be presented in Trans. ISIJ. in the near future.
|
