| 摘要 |
<p>Low-loss Mn-Zn-ferrites, for magnetic cores having low inconstancy are prepd by mixing MnCO3, ZnO and Fe2O3, esp. wet-grinding, (i) presintering the mixed and ground raw materials at a temp which lies above the MnCO3 dissociation temp in an atmos, such that oxidn of the MnO obtd, from decomposing MnCO3 on presintering is prevented, (ii) heating and sintering the pre-sintered and compressed starting materials in a non-oxidising atmos. and (iii) cooling the sintered ferrite in an equilibrium atmos. such that O2-stoichiometry of ferrite set up on sintering is maintained. Pref. (I) takes place in a protective gas, esp. very pure N2, at 500-1100 (1000) degrees C, or in producer gas, or in a sealed container in air, followed by quick cooling; (ii) takes place esp. in a productive gas, partic, N2 at 1050-1350 degrees C for 15 hrs. Pre-sintered raw material may be admixed with 0-0.1 wt.% SiO2, 0-3 wt.% TiO2, 0-0.3 wt.% CaCO3 and 0-0.1 wt.% V2O5.</p> |
