Associate Professor of Mechanical Engineering, California Institute of Technology, Pasadena, Calif.
Baen, Spencer R.
Graduate Student in Mechanical Engineering, California Institute of Technology, Pasadena, Calif.
Pages: 13 Published: Jan 1950
This paper presents a critical review of the X-ray diffraction data of the sigma phase in the binary alloys of iron, cobalt, nickel, chromium, and vanadium. Although the crystal structure of the sigma phase is still unknown, a tentative tetragonal unit cell is suggested to describe the structure, at least as a first approximation. On the basis of this cell the lattice parameters of the various binary sigma phases are computed. The case of a ternary sigma solid solution in the iron-chromium-molybdenum system is also discussed and the influence of molybdenum on the lattice parameter of sigma is described. A short discussion is given on the occurrence of the sigma phase in binary alloys and its relation to atomic diameter and crystal structure of the two component metals.
Paper ID: STP46103S