| 摘要 |
PURPOSE:To obtain a reinforcing material for a ferrite head which can be melt- stuck to a ferrite head core with glass, by varying a coefficiency of thermal expansion over a wide range by specifying the composition ratio of TiO2, MgO and CaO. CONSTITUTION:A reinforcing material for a ferrite head is the sintered ceramic of a mixture of TiO2, MgO and CaO, and the composition of three materials is within a range encircled with a thick line. Namely, 5<=x<=90, 0<=y<=90, and 2.5<=z<=95, and x+y+z=100 where (x) is the mol% of TiO2, (y) is that of MgO, and (z) is that of CaO. To be concrete, the coefficient of thermal expansion of ceramic obtained by mixing and sintering 80mol% TiO2, 5mol% NgO and 5mol% CaO is 80X10<-7>/ deg.C. While 50mol% TiO2 is used fixedly, the mixing ratio of MgO and CaO is varied to set the coefficient of thermal expansion linearly and freely over a wide range. |
