PCBN材料的组织结构与力学性能

以CBN-TiN-Ti-Al₂O₃为初始原料，采用高温高压法在1500 ℃不同保温时间下制备PCBN材料，探讨其在不同保温时间下的物相组成、显微结构、力学性能和切削性能。结果表明:保温时间对PCBN材料物相组成无明显影响，但有助于提高其结晶度，实现其烧结均匀化和致密化；在保温时间为9.00 min时，能获得综合性能最佳的PCBN材料，其相对密度为99.1%，抗弯强度为910.9 MPa，磨耗比为7120，显微硬度为33.5 GPa；用此PCBN做成的刀具加工模具钢零件，最多可加工365个。 

Microstructures and mechanical properties of PCBN materials

The PCBN material was prepared by high temperature and high pressure method at 1 500℃ and different holding times with CBN-TiN-Ti-Al₂O₃ as the initial raw material. The phase compositions, microstructures, mechanical properties and cutting performance of PCBN under different sintering holding times were discussed. The results show that the holding time has no obvious effect on the phase compositions of PCBN, but it is helpful to improve its crystallinity and to realize its sintering uniformity and densification. When the holding time is 9.00 min, the PCBN material with the best comprehensive performance can be obtained with the relative density of 99.1%, the bending strength of 910.9 MPa, the wear ratio of 7120 and the microhardness of 33.5 GPa. The tool made of this PCBN can process up to 365 die steel parts.