MANUFACTURE OF CERAMIC LUMINOUS TUBE FOR HIGH PRESSURE METALLIC VAPOR DISCHARGE LAMP

摘要

PURPOSE:To unify the crystal structure of a ceramic tube and a ceramic cap so as to obtain a ceramic luminous tube with high dimensional accuracy and without the fear of the gas leakage at the inserted portion by inserting the flange portion of a raw material cap into the end portion of a raw ceramic tube and sintering them. CONSTITUTION:The high purity alpha-alumina powder used for the raw material of a raw cap 4 has relatively small initial sintering shrinkage and is formed to the cylindrical raw cap 4 provided with a flange portion 8. And the high purity alpha-alumina powder used for the raw material of a raw ceramic tube 2 has a larger initial sintering shrinkage than that of the high purity alpha-alumina powder used for the said raw cap 4 and is formed to the raw ceramic tube 2 of specified length. After inserting the cylindrical portion 6 of the non-sintered raw cap 4 into one end portion of the non-sintered raw ceramic tube 2, they are sintered with the conventional method to produce a ceramic luminous tube 16 of unified crystal structure.