可加工B_4C/BN复相陶瓷的制备与性能研究  

Fabrication and Properties of the Machinable B_4C/BN Composites Ceramics

作　　者：江涛[1] 金志浩[1] 乔冠军[1] 

机构地区：[1]西安交通大学 金属材料强度国家重点实验室,陕西西安710049

出　　处：《稀有金属材料与工程》2007年第A03期585-588,共4页Rare Metal Materials and Engineering

摘　　要：采用热压烧结工艺制备了B_4C/BN可加工复相陶瓷,热压烧结工艺参数为:热压温度为1850℃,热压压力为30 MPa,保温时间为1 h。通过向B_4C基体中加入不同含量的h-BN来研究h-BN的含量对所制备的B_4C/BN复相陶瓷材料的力学性能和可加工性能的影响,并通过XRD和SEM来研究复相陶瓷的物相组成和显微结构。结果表明:随着复相陶瓷中的h-BN含量的增加,B_4C/BN复相陶瓷的密度逐渐降低;B_4C/BN复相陶瓷的抗弯强度和断裂韧性有所降低;复相陶瓷的维氏硬度大幅度降低;而硬度的降低导致了复相陶瓷的可加工性能得到显著的提高,当h-BN的含量高于20%(质量分数,下同)时,B_4C/BN复相陶瓷具有良好的可加工性能。The machinable B4C/BN composites ceramics were fabricated by hot-pressing sintering process with sintering temperature of 1850 ℃, the pressure of 30 MPa and holding time of 1 h. Effects of the h-BN content on the mechanical properties and machinability of the B4C/BN composites were investigated, and the phase composition and microstructure of the B4C/BN composites were investigated by X-ray diffraction and SEM, respectively. The experimental results showed that, with h-BN content increasing, the density of composites decreased gradually resulting in corresponding decrease in fracture strength and fracture toughness of the composites; and the Vickers hardness of composites decreased gradually, while the machinability was improved noticeably. When the h-BN content was more than 20%, the B4C/BN composites exhibited excellent machinability.

关 键 词：碳化硼 六方氮化硼 复相陶瓷 热压烧结 可加工陶瓷 

分 类 号：TQ174.1[化学工程—陶瓷工业]