| 摘要 |
PURPOSE:To enable a device to have high dimensional accuracy and to increase the performance of the device by adding a certain amount of glass to ferrite so as to reduce its contraction coeffiecient to 10% or less. CONSTITUTION:After 0.3-15wt% noncrystalline glass powder with the softening point at 700 deg.C or less is added to ferrite powder and mixed together, the mixture is sintered at temperatures higher than those at which the minute shrinkage of the ferrite begins. Although a compact obtained by pressurizing the ferrite powder in a metal mold contains void holes, diffusion will occurs among atoms constituting the ferrite if the compact is heated at temeprature higher than 800- 1,000 deg.C. As the minute shrinkage progresses, the compact indicates almost nearly no magnetism, however, the strength thereof increases when it begins to function as a magnetic material. |
