A calculation of viscosities for iron-metalloid liquids
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Input
Input
Lattice
Physical Parameters
Parameter
Calibration
Optional procedure B r o a d e n i n g and Doublet Corrections
Procedure
C o n s t r u c t i o n of (see E q . ( 1 ) )
the C o m p o s i t i o n - D e p t h P r o f i l e
Output Plots
and Tables
Fig. 5--Schematicdiag~mof the in~rmationflow in the computerp~gram "TIBAC".
depth profile using Eq. [1]. Output is produced in plotted and tabular forms. The program is well documented to facilitate adoption to the user's particular system. It has been written to function with FORTRAN 77-type compilers but should also function without modification in earlier FORTRAN compilers. Core requirements on a CDC- 175 computer were 196 K of 60 bit words, and execution times varied from 60 to 200 seconds.
REFERENCES 1. K. E. Wiedemann and J. Unnam: "TIBAC--Transformation of an Intensity Band for the Analysis of Composition," LAR-13356, COSMIC, University of Georgia, 1984. 2. B. Ia. Pines and E.F. Chaidouski: Doklady, Academie Nauk. SSSR, 1956, vol. 111, pp. 1234-37. 3. D.R. Tenney, J.A. Carpenter, and C. R. Houska: Journal of Applied Physics, 1970, vol. 41(11), pp. 4485-92. 4. J. Unnam, J.A. Carpenter, and C.R. Houska: Journal of Applied Physics, 1973, vol. 44, pp. 1957-67. 5. E.S. Bumps, H.D. Kessler, and M. Hansen: Trans. ASM, 1953, vol. 45, pp. 1008-28. 6. C. Feng and C. Elbaum: Transactions Am. Institute of Metallurgical Engineers, 1958, vol. 212, pp. 47-51. 7. C. E. Shamblen and T. K. Redden: Science and TechnologyandApplication of Titanium, 1968, pp. 199-208. 8. R.N. Shenoy, J. Unnam, and R.K. Clark: Journal of Oxidation of Metals, 1986, in press. 9. K.E. Wiedemann and J. Unnam: Journal of Applied Physics, 1985, vol. 58, pp. 1095-1101.
A Calculation of Viscosities for Iron-Metalloid Liquids YOSHITAKE NISHI and AKIRA YOSHIHIRO Using the heat of vaporization, the free energy of mixing, the ionic radius, and the atomic radius, a method of calculation is suggested for liquid viscosity. Furthermore, the supercooled liquid viscosities are calculated for Fe-B alloy. The critical cooling rate for glass formation is estimated by the use of the supercooled liquid viscosity and the homogeneous nucleation theory for Fe-17 at. pct B alloy. Based on the kinetic and thermodynamic points of view, the viscosity is an atomic scale measure of the thermal motion and structure of materials in the liquid state. Therefore, the viscosity has been known to be one of the most sensitive factors controlling the reaction and crystallization in the liquid. 1~ However, it is not easy to measure the viscosity in the liquid alloys. Thus, we suggest a practical method to obtain the viscosity as a function of temperature. Correction of Eyring Assumption. Using hole theory, 5 the apparent activation energy E v 6-9 of viscosity has been correlated with a heat of vaporization Evap ~~in pure materials.
Ev = Evap/n
[1]
Here n is a constant, n is 3.5 -+ 0.5 for unassociated liquids and about 16 --- 8 for alloy liquids. Since metals are generally ionized in the liquid state, Eyring has sugge
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