| 摘要 |
PROBLEM TO BE SOLVED: To obtain an alumina sintered compact having low Na and K contents and usable even in a semiconductor producing device without using powdery stock consisting of ultrahigh purity particles. SOLUTION: The total amt. of Na2 , K2 O, SiO2 , CaO, Fe2 O3 and TiO2 contained as impurities in this alumina sintered compact is 100-10,000ppm and the Na2 O and K2 O account for <=4wt.% of the total amt. At least an acid compd. is added to powdery stock for an alumina sintered compact, metals in the stock are allowed to react with the acid compd. to form metallic salts and these salts are removed. |
