| 摘要 |
PROBLEM TO BE SOLVED: To produce a materiel having an excellent resistance to thermal shock by incorporating a specified molar ratio of Fe2 O3 , NiO and ZnO as main components and the specified molar ratio of SiO2 and Cr2 O3 as the secondary components. SOLUTION: In a Ni-Zn based ferrite, 47-50 mol.% Fe2 O3 , 15-35 mol.% NiO and 10-33 mol.% ZnO are incorporated as the main components and 0.05-2.0 wt.% Bi2 O3 , 0.05-1.0 wt.% SiO2 and 0.05-1.5 wt.% Cr2 O3 per main components are incorporated as the secondary components. And in a Ni-Cu-Zn based ferrite, 47-50 mol.% Fe2 O3 , 15-30 mol.% NiO, <=10 mol.% CuO and 10-33 mol.% ZnO are incorporated as the main components and 0.05-2.0 wt.% bi2 O3 , 0.05-1.0 wt.% SiO2 and 0.05-1.5 wt.% Cr2 O3 per main components are incorporated as the secondary components. The Fe2 O3 , NiO, CuO and ZnO being the main components form a crystal phase, and the Bi2 O3 and SiO2 being the secondary components form a vitreous phase as a stress relaxation layer existing at an intercrystalline boundary. |
