包覆型BN-AIN复合粉体研究

Preparation of BN-Coated AIN Composite Powders

利用包覆法,首先通过将AIN粉体均匀分散到硼酸(H38O3)和尿素(CO(NH2)2)的无水乙醇溶液中,制备出与硼酸和尿素均匀混合的AIN粉体。然后在氮气氛下,经过氮化处理来制备BN-AIN的复合粉体。DTA/TG分析显示,氮化反应从800℃开始,到1100℃时结束。XRD和TEM分析发现,复合粉体是由非晶态的BN均匀包覆AIN的复合颗粒组成。

AlN-BN composite powders with the microstructure of micrometer-sized AlN particles coated with BN particles were prepared via a chemical reaction, which used a mixture of boric acid （H3BO3） and urea （CO（NH2）2） as reactants coated on the surface of the AlN particles to react in nitrogen ambient. DTA/TG analysis indicated that urea and boric decompose at 180-350 ℃ and generate ammonia gas （NH3） and boric oxide （B2O3）, respectively. The two products react to form BN at 800-1100 ℃. The XRD and TEM studies showed that the coating layer （BN） was composed mostly of amorphous BN at the reaction temperature of 850-1100 ℃