纯相PcBN的高温高压制备综述

A review of preparing binderless PcBN at high temperature and high pressure

PcBN是cBN的聚晶体,具有尺寸大、各向同性、无解理面等优点,因而应用广泛。商用PcBN大多采用添加黏结剂的方式进行烧结以降低烧结条件,通常是在压力为5.5~7.7 GPa、温度为1600~2300 K条件下合成的。但黏结剂也降低了产品的性能,其维氏硬度在22~45 GPa。鉴于材料本身就是最好的黏结剂,本文对使用4种不同初始材料制备纯相PcBN的烧结行为及材料性能进行介绍和评价。用cBN作为初始材料并配合相关工艺能制备出性能较好的纯相PcBN材料。

Polycrytalline cubic boron nitride,PcBN for short,has the advantages of large size,isotropy and no cleav-age plane so that it is widely used.Commercial PcBNs are generally sintered with binders to reduce sintering conditions to pressures ranging from 5.5 to 7.7 GPa and temperatures of 1600 to 2300 K.However,binders reduce the perform-ance of the product,Vickers hardness ranging from 22 to 45 GPa for example.Based on the fact that the material itself is the best binder,pure phase PcBNs were prepared by four different initial materials,the sintering behavior and the properties of which were introduced and evaluated.In conclusion,the pure phase PcBN material with good perform-ance can be prepared by using cBN as the initial material and adopting related processes.