以Ar气氛保护管式炉常压合成的Ti3SiC2粉体和商业立方氮化硼微粉为原料,采用六面顶压机,在4.5GPa、1050℃保温10min的条件下制备出Ti3SiC2结合立方氮化硼超硬复合材料。用扫描电子显微镜观察了复合材料的微观结构,用X射线衍射和电子能谱分析样品的结构和成分。结果表明:立方氮化硼颗粒均匀地分布在基体中,且两者界面结合良好;磨损实验之后,立方氮化硼颗粒仍然与基体结合良好。复合材料基体主要成分为Ti3SiC2以及少量TiC作为第二相。用气氛保护管式炉不能在常压条件下制备这种复合材料,主要原因不是立方氮化硼在常压条件下的高温相变,而是Ti3SiC2在氮化硼存在时的高温分解。
Ti3 SiC2-cBN composite was prepared by a cubic high pressure apparatus under 4. 5 GPa at 1 050 ℃ for 10 min with commercial cubic boron nitride (cBN} powders and Ti3 SiC2 powders as starting materials. The Ti3 SiC2 powders were prepared in a tube furnance under Ar atmosphere. The microstructrure was observed using scanning electron microscope. The phase and the composition were analyzed using X-ray diffraction and electron energy dispersive spectra. The results show that the eBN particles were homogenously distributed in Ti3 SiC2 matrix. The cBN particles are bonded with the matrix during friction and are not removed. The main phase of the composites matrix is Ti3 SiC2 with a little TiC as a second phase. However, the composites cannot be obtained in a tube furnace under normal pressure. The main reason is not the phase transformation of cBN at a high temperature under normal pressure. It is because that Ti3 SiC2 reacts with BN and decomposes at a high temperature.