【摘要】 聚晶立方氮化硼由于其优异的机械性能和物理化学稳定性而备受关注，在机械加工领域有着十分广泛的应用前景。本文通过将Al、Co、W、Ti N与cBN微粉球磨混合，随后通过高温高压烧结法在1500°C,5.5 GPa的条件下与不同Co含量的WC-Co硬质合金基底烧结结合，系统的研究了不同合金基体对PcBN复合材料界面强度的影响及作用机理。当硬质合金为WC-11.5%Co时，PcBN复合片的抗弯强度以及维氏硬度值综合效果最好分别为1623.67MPa和46.03 GPa。通过微观结构分析，cBN相与WC-Co合金基底之间的紧密结合主要依靠在高温高压的条件下Co原子的相互渗透扩散，Co原子由浓度高的WC-Co合金基底向浓度低的cBN相进行扩散扎钉，最终实现的界面结合。通过热处理，材料在表面发生物理损伤，主要表现形式为结合剂相从样品表面析出，与此同时试样表面发生氧化，生成B₂O₃、Al₂O₃和TiO₂等氧化相。更多还原

【Abstract】 polycrystalline cubic boron nitride has attracted attention because of its excellent mechanical properties and physical and chemical stability, which has a wide application prospect in the field of machining. In this paper, Al, Co, W, TiN and cBN powder were mixed by ball milling,and then sintered with WC-Co cemented carbide substrates with different Co contents at 1500℃ and 5.5 GPa by high temperature and high pressure sintering method. The influence of different alloy substrates on the interfacial strength of PcBN composite and mechanism were systematically studied. When the cemented carbide is WC-11.5 %Co, the combined effects of bending strength and Vickers hardness of PcBN composite are 1623.67 MPa and 46.03 GPa. By microstructure analysis, the combination between cBN phase and WC-Co alloy substrate mainly depends on the mutual penetration and diffusion of Co atoms under the conditions of high temperature and high pressure. The Co atoms diffuse and pin from the WC-Co alloy substrate with high concentration to the cBN phase with low concentration, and finally the interface is bonding. Through heat treatment, the material is physically damaged on the surface, which is mainly manifested by the precipitation of binder phase from the surface of the sample. At the same time, the surface of the sample is oxidized to form oxidation phases such as B₂O₃, Al₂O₃ and TiO₂.更多还原