Abstract
Fernico alloys are now being used for glass sealing because of its low expansion coefficient fitted to hard glasses. These alloys transform from γ to α phase at low temperature on cooling. Sometimes glasses are broken after sealing by the stress induced with the martensitic transformation of Fernico at near room temperature. In this experiment the effects of heat treatments on the suppressing of the transformation of Fernico were examined. The results obtained are as follows: (1) The transformation processes in Fernico are considered as the same as in Fe-Ni binary system which consist of transformation by diffusion at high temperature and of martensitic transformation at low temperature. (2) By annealing at γ+α region after cold working, the transformation point falls remarkably as compared with normal high temperature treatment. (3) The expansion coefficient of the specimen annealed at γ+α region does not so differ from normal that of a specimen. Thus such a heat treatment may be useful for glass sealing with Fernico.
