Issue
J. Phys. Colloques
Volume 48, Number C8, Décembre 1987
Fifth European Conference on Internal Friction and Ultrasonic Attenuation in Solids
Page(s) C8-233 - C2-237
DOI https://doi.org/10.1051/jphyscol:1987832
Fifth European Conference on Internal Friction and Ultrasonic Attenuation in Solids

J. Phys. Colloques 48 (1987) C8-233-C2-237

DOI: 10.1051/jphyscol:1987832

A COMMENT ON THE 87°C I.F. PEAK IN Fe-V-N ALLOYS

TINGGUO CHEN, XIAOMING XIE et ZILIANG WU

Shanghai Institute of Metallurgy, Academy of Sciences of China, Shanghai, China 200050


Abstract
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.