| 摘要 |
PURPOSE: To inhibit the growth of grains and to improve strength and toughness by incorporating ZrO2 into Ni-Zn ferrite having a specified compsn. CONSTITUTION: ZrO2 is added by 0.1-10.0 pts.wt. to 100 pts.wt. Ni-Zn ferrite consisting of, by weight, 59-72% Fe2 O3 , 7-31% NiO, 1-23%, ZnO, 0-4% CuO and 0-2% MnO respectively in terms of it and they are wet-mixed, dried, calcined, granulated, compacted into a prescribed shape and fired in an oxygen atmosphere to obtain a sintered compact having 1-18μm average grain diameter, >=15kg/mm<2> three-point bending strength and >=1.5kgf.cm/cm<2> impact strength measured by a Charpy impact test. The objective ferrite substrate 10 is a plate made of the sintered compact. Plural dividing grooves 11 are formed in the surface of the substrate 10 in longitudinal and transverse directions, and electrodes and electric circuits are multiprinted by film printing. After baking, the substrate 10 is divided along the grooves 11 and many electronic parts are simultaneously obtd. |
