| 摘要 |
1326730 Surface coated Si 3 N 4 UNITED KINGDOM ATOMIC ENERGY AUTHORITY 21 Aug 1970 [22 Aug 1969] 41889/69 Heading B2E [Also in Division C1] Si 3 N 4 coated with a surface layer of Al 2 O 3 is prepared by either decomposing an aluminium compound, e.g. Al(NO 3 ) 3 , or hydrolysing Al 2 Cl 6 , on the surface of the nitride. The nitride may be additionally coated with B 2 O 3 which may be prepared by decomposing a boron compound, e.g. H 3 BO 3 on the surface of the nitride. The oxides may be present in an amount between 0.1-10% by wt. of the nitride. The coated nitride is preferably prepared by immersing the nitride in Al(NO 3 ) 3 solution, drying and calcining at 850‹C. The Al 2 O 3 -B 2 O 3 layer may be prepared by subsequently immersing the Al 3 O 3 coated nitride in H 2 BO 3 , drying and then calcining at 850‹C. |
