| 摘要 |
1,241,104. Boron nitride. LOCKHEED AIRCRAFT CORP. 12 Aug., 1969 [19 Aug., 1968], No. 40363/69. Heading C1A. A boron filament is given a boron nitride surface coating, at least 0À1 Á thick, which is adherently bonded, and whose surface is continuous, by first forming a liquid boron oxide coating on the filament, and then converting this to the nitride by heating in a nitrogencontaining atmosphere. The preferred temp. for forming the oxide coating is within the range 560-1000‹ C. and the preferred temp. for nitriding is from 350-1100‹ C. The filaments thus prepared are for use as reinforcement in composite metal and metal alloy matrices. The liquid boron oxide coating may be prepared by heating the boron filament surface in an oxidizing atmosphere such as air, oxygen, or a mixture of oxygen with nitrogen or inert gas. |
