| 摘要 |
PURPOSE:To produce highly concentrated Mn-Zn ferrite with low porosity by a method wherein a powder compact to which specified wt% of at least one kind out of Bi2O3, V2O5, In2O3 and SnO2 is added is primary-sintered in nitrogen atmosphere and then pressurized with thermal hydrostatic pressure within specific range. CONSTITUTION:Within Mn-Zn ferrite comprising 51.0-54.0mol% of Fe2O3, 26.0-31.0mol% of Mn, 14.0-22.0mol% of Zn, a powder formed body to which 0.01-2.0wt% of at least one kind out of Bi2O3, V2O5, In2O3 and SnO2 is added is primary-sintered in nitrogen atmosphere and then pressurized with thermal hydrostatic pressure of 800-1,600kg/cm<2>. With the upper limit of additive exceeding 2wt%, the magnetic permeability of powder compact is abruptly deteriorated apt to leave numerous pores unable to attain to high concentration at the HIP processing pressure not exceeding 800kg/cm<2> while the characteristics of powder compact is also deteriorated because of excessive distortion at the HIP processing pressure exceeding 1,600kg/cm<2>. |
