| 摘要 |
PURPOSE:To improve transparency by forming a porcelain having a specific composition expressed by a specific formula, a specific average crystal grain diameter and a prescribed light transmittance in a condition including a specific thickness of the porcelain, measuring wavelength, scattered light and reflection loss. CONSTITUTION:A sintered compact is formed by adjusting each oxide powder of Pb, La, Zr and Ti to have a prescribed composition, press molding it and firing the molded body in a vacuum of 1X10<-2>-1X10<-5>Torr at 1150-1250 deg.C for 0.25-2hr. The transparent high density porcelain expressed by the formula, (x=0.087-0.093, y/z=0.66/0.34-0.64/0.36), 0.05-5mum in average crystal grain diameter, 0.2mm in the thickness of the porcelain, >=65% in light transmittance in the condition of 0.633mum measuring wavelength and including scattered light and reflection loss is obtained by burying the sintered compact worked into a thin plate having the prescribed thickness in a heat resistant vessel filled with a powder such as a smelting ZrO2 powder having 50-3000mum average particle diameter and subjecting it to hot hydrostatic pressing with gaseous Ar or the like as a pressure medium of 500-700kg/cm<2> at 1050-1200 deg.C for 0.5-2hr. |
