J. Phys. Colloques
Volume 48, Numéro C8, Décembre 1987Fifth European Conference on Internal Friction and Ultrasonic Attenuation in Solids
|Page(s)||C8-233 - C2-237|
J. Phys. Colloques 48 (1987) C8-233-C2-237
A COMMENT ON THE 87°C I.F. PEAK IN Fe-V-N ALLOYSTINGGUO CHEN, XIAOMING XIE et ZILIANG WU
Shanghai Institute of Metallurgy, Academy of Sciences of China, Shanghai, China 200050
It is shown in the present paper that the 87°C internal friction peak in the Fe-V-N system often refered to in the literature does not behave like an s-i interaction peak. It is induced by the nitrogen atoms accupying the anion hole of a defective vanadium nitride precipitate. The effective holes capable of holding interstitials for internal friction generation must be situated in the interface between the α-Fe matrix and the defective precipitate. The 95°C peak occurs for a precipitate with a N/V ratio of 0.7 to 0.8, corresponding to the metastable compound V4 N3 of of highest hole concentration. Lattice parameter measurements show that a stoichiometric VN precipitate with ao=4.13Å produce no 95°C peak while a defective VN0.69 with ao=4.08Å can give 95°C peak.