The porcelain null for the insulator which is superior in steep wave

摘要

PROBLEM TO BE SOLVED: To ensure a characteristic, equal to the surge strength, of porcelain, wherein a corundum crystal phase is relatively and uniformly distributed without actually accempaning a fine porosity, by making the mean density of a corundum crystal, enclosing the fine porosity, have a specific value or less, even the fine porosity, in the fine structure of an alumina-containing porcelain, exists in a condition where the fine porosity is selected by the corundum crystal. ;SOLUTION: A nearly mean diameter has about 0.5-30μm in a porosity existing in a bulky corundum crystal and/or a corundum aggregate, satisfying a required surge strength of about 2000KV/μs or more, and having a containing quantity of the corundum crystal of about 5-40wt.%, also a mean particle diameter of the fine porousity of about 20-30μm. The mean condensity of the corundum crystal enclosing the porosity is preferably about 10 pieces/mm² or less, and alumina is to be suitably added about 5-40% as raw material. This porcelain can be suitably used as a high-voltage suspension insulator, for displaing surge strength of about 2000kV/μs or more.;COPYRIGHT: (C)1998,JPO