烧结温度对合成PCBN复合片性能的影响

Effect of Sintering Temperature on Properties of Synthetic PCBN Composite

将立方氮化硼微粉和Ti、AlN微粉按一定的质量比进行混料,在高温和超高压条件下合成聚晶立方氮化硼(PCBN)复合片,利用X射线衍射和扫描电子显微镜对试样的物相组成和显微结构进行分析,研究了烧结温度对PCBN的力学性能、显微结构以及切削性能的影响。研究表明:在超高压5.5 GPa,高温1400~1550℃之间,PCBN复合片中的物相由BN、AlN、TiN、TiB2和W组成;PCBN中的cBN颗粒通过反应生成的物相彼此连接;PCBN的力学性能和切削性能随烧结温度的升高增强。

The cubic boron nitride powders,TiN and Al powders were mixed at a certain mass ratio.Polycrystalline cubic boron nitride(PCBN)was synthesized under high temperature and ultrahigh pressure conditions.The phase constitution and microstructure of specimens were analyzed by X-ray diffraction and scanning electronic microscopy.The effect of sintering temperature on the mechanical properties,microstructure and cutting performance of PcBN were investigated.The research shows that the phase in PCBN composite sheet is composed of BN,AlN,TiN,TiB2 and W between 5.5 GPa and high temperature of 1400~1550℃;the cBN particles in PCBN are connected to each other through the reaction phase;the mechanical and cutting properties of PCBN increase with increasing sintering temperature.