METHOD OF REDUCING MAGNESIUM LOSS DURING SINTERING OF ALUMINIUM OXIDE ARTICLES

摘要

A method for reducing the loss of magnesium during the sintering of aluminum oxide articles, such as ceramic discharge vessels for lighting applications. Magnesium oxide is added to aluminum oxide articles to control grain growth during sintering, b ut the sintering causes magnesium loss from the article. In order to address this problem, on e or more aluminum oxide articles that are enriched in magnesium oxide are added to th e sintering furnace to stem the loss of magnesium oxide in the remaining articles. The enriched aluminum oxide article is made by soaking a porous aluminum oxide article in an aqueous solution of magnesium nitrate and heating the porous article to convert the magnesium nitrate to magnesium oxide. The enriched articles may then be added in one o r several locations to the sintering furnace, where the magnesium from the enriched articles is released to suppress the magnesium loss.