摘要
采用热压烧结制备h-BN体积含量分别为30%和40%的可加工SiC/30%h-BN和SiC/40%h-BN复相陶瓷,并在不同温度和氧化气氛下对复相陶瓷样品进行热处理。测试了预制Vickers压痕的复相陶瓷样品在热处理前后的强度和表面硬度,并通过X射线衍射和扫描电子显微镜等研究了复相陶瓷表面成分和显微结构的变化。结果表明:氧化气氛下的热处理可恢复陶瓷在加工时由表面损伤降低的强度,1100℃热处理2h的陶瓷效果最佳。经1100℃热处理2h后,带压痕的SiC/40%h-BN复相陶瓷的强度恢复到389.81MPa,表面硬度从6.11GPa提高10.48GPa。SiC和h-BN的高温氧化行为是强度恢复和表面硬度升高的主要原因。
Machinable SiC/h-BN ceramics with 30% （volume fraction,the same below） and 40% h-BN were fabricated by hot pressing sintering,and then the samples were heat-treated at different temperatures for 2 h in oxidizing atmosphere. The strength of SiC/h-BN samples with prefabricated Vickers indentation and the surface Vickers hardness of the SiC/h-BN samples before and after heat treatment were tested. The microstructure and surface component of the SiC/h-BN samples were characterized by scanning electron microscope and X-ray diffraction. The results show its strength decreases by indentation,the indentation can be recovered by heat treatment in oxidizing atmosphere,and the restoration of the strength of the sample treated at 1 100 ℃ for 2 h is the best. After heat-treated at 1 100 ℃ for 2 h,the strength of SiC/40%h-BN with indentation recovers is up to 389.81 MPa,and its hardness in-creases from 6.11 to 10.48 GPa. It shows that the high temperature oxidation treatment of SiC and h-BN results in strength recovery and Vickers harness improvement.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2010年第8期1503-1508,共6页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(50772086)
国家“863”计划(2007AA03-Z558)资助项目
关键词
碳化硅
六方氮化硼
热处理
表面硬化
可加工陶瓷
silicon carbide
hexagonal boron nitride
heat treatment
surface hardening
machinable ceramics
