Investigation of a ferrite/silicon nitride composite concept aimed at automotive applications
Résumé
This paper presents the investigation of the behavior of a Fe-1.5 wt% Si thin sheet upon plasma-assisted nitriding at 570°C. It had been confirmed that a very fine and intense precipitation of amorphous silicon nitride occurs as nitrogen diffuses into the sheet. The precipitates, the size of which is comprised between several and several tens of nanometer, display a cubic morphology in spite of their amorphous structure. These cubes adopt a particular morphology in relation to the matrix with their faces parallel to the {100} plane family. These precipitates cause a notable hardening of the alloy and it was possible to harden a 1 mm sheet across its whole thickness in under 8 h.