University “Politehnica ” Bucharest

A short selective review of concepts and ideas concerning the conditions in which the melts may be undercooled in vitreous state is presented. The important role of the cooling rate in the broadening of the glass forming domains, encouraging the apparition of the new ultra high cooling rate techniques, is underlined. Correlation between the undercooling in the vitreous state tendency and basicity (pB in %) is demonstrated. The new evidenced fact that the classic glass formers are located in the central field of the basicity scales, i.e. approximately between 40 and 60 % of pB, is discussed. The speed of the heath dissipation Vhd, as a very general glass forming condition, is defined. The fulfilling of this condition allows obtaining every liquid or melt in vitreous state. The two new possibilities of melts undercooling tendency estimation are easily utilisable the necessary data being accessible