Processus De Formation Du Film D’oxyde De L’acier Ferromagnétique À L’air Ambiant Et Sous Vide

Résumé: When applying a magnetic field around a contact of a ferromagnetic couple, the latter largely modifies the behavior of friction and wear of the contact. The friction tests are carried out in two different gaseous environments: with ambient air and under vacuum at 5.10-5 Pa. In ambient air, the effect of the magnetic field on the wear rate is significant, noting that the application of a sufficient magnetic field (H = 10 kA/m) decreases the wear rate from 6 to 10 time. The effect of the magnetic field on the tribology of contact in the open air remains valid up to a limit intensity H = 40 kA/m. Beyond this limit, other effects are manifested: increased magnetic attraction and contact temperature due to eddy currents. In addition, non-oxidized wear particles, resulting from abrasive wear at the start of sliding, remain trapped due to the strong magnetic attraction. The vacuum wear process is completely different. Note here that the wear is adhesive and severe. The adhesion causes a particle transfer between the pin and the disc. On the other hand, under vacuum the magnetic field does not generate an oxide layer, since the oxygen level in this environment is negligible.

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