# Accession Number:

## AD0614009

# Title:

## THERMODYNAMICS OF MARTENSITIC F. C. C. REVERSIBLY YIELDS B. C. C. AND F. C. C. REVERSIBLY YIELDS H. C. P. TRANSFORMATIONS IN THE IRONRUTHENIUM SYSTEM,

# Descriptive Note:

# Corporate Author:

## MANLABS INC CAMBRIDGE MASS

# Personal Author(s):

# Report Date:

## 1965-03-01

# Pagination or Media Count:

## 25.0

# Abstract:

A thermodynamic analysis of the iron-ruthenium system has been performed on the basis of the regular solution model by approximating the lattice stability of h. c. p., f. c. c. and b. c. c. ruthenium as being similar to nonmagnetic iron. The analysis permits calculation of the entire phase diagram, the T sub o-x curves for diffusionless f. c. c. reversibly yields b. c. c. and f. c. c. reversibly yields h. c. p. reactions at one atmosphere and the compositional dependence of the f. c. c.b. c. c. h. c. p. pressure-temperature triple points, all of which compare reasonably well with observation. The driving force for the martensitic f. c. c. reversibly yields b. c. c. reaction is temperature dependent and similar to that observed for iron-nickel alloys. The driving force for the martensitic f. c. c. reversibly yields h. c. p. reaction is about 50 calmole and, as expected from crystallographic considerations, is smaller than the corresponding f. c. c. reversibly yields b. c. c. driving force. Author