以BN、SiO2和A1N为原料,采用热压工艺制备出BN-30%SiO2复合陶瓷,研究了A1N添加量对复合陶瓷物相组成、微观组织及力学性能的影响。结果表明:随着A1N的引入,烧结后的复合陶瓷中出现SiAlON相。当材料中AIN加入量小于5%时,可发现有非晶SiO2相。随A1N加入,复合陶瓷弯曲强度和断裂韧性较BN-30%SiO2复合陶瓷均有所提高,并随A1N添加量增加呈先升高后降低趋势,而弹性模量增加并不明显。AIN添加量为5%时,材料弯曲强度和断裂韧性达到最大值(分别为247.0MPa和4.02 MPa·m^1/2),与BN-Si02复合陶瓷相比,分别提高了57.5%和40.6%。
The BN-based composite ceramics were fabricated with BN, SiO2 and A1N as raw materials by an hot-press sintering process. The effect of A1N content on the phase constitution, microstructure and mechanical properties of the composites was investigated. The results show that SiA1ON can appear in the composites sintered by a hot pressing due to the introduction of A1N. The amorphous SiO2 appears in the composites without A1N or with A1N of 〈 5%. The flexural strength and fracture toughness of the composite, which are greater than those of BN-30%SiO2 composite, firstly increase and then decrease with the increase of AIN. The elastic modulus does not increase. When AIN content is 5%, the flexural strength and fracture toughness are 247.0 MPa and 4.02 MPa.m^1/2, respectively, which are 57.5% and 40.6% greater than those of BN-SiO2 composites.